Difference between revisions of "Rikesh Patel"

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Assistant Professor, Department of Electrical and Electronic Engineering, University of Nottingham
 
Assistant Professor, Department of Electrical and Electronic Engineering, University of Nottingham
  
'''Address''' : A46 Coates Building, University Park, Nottingham, NG7 2RD, UK
+
Address: A46 Coates Building, University Park, Nottingham, NG7 2RD, UK
  
'''Phone''' : +44 (0)115 84-67892
+
Phone: +44 (0)115 84-67892
  
'''Email''' : rikesh.patel[[Image:Atnotts.png|110px|link=]]
+
Email: rikesh.patel[[Image:Atnotts.png|110px|link=]]
  
'''ORCID''' : [https://orcid.org/0000-0003-0751-4533 0000-0003-0751-4533]
+
ORCID: [https://orcid.org/0000-0003-0751-4533 0000-0003-0751-4533]
 +
 
 +
External links:
  
 
[https://nottingham-repository.worktribe.com/person/234634/rikesh-patel/outputs UoN repository] [http://eprints.nottingham.ac.uk/view/people/Patel=3ARikesh=3A=3A.html (old link)]
 
[https://nottingham-repository.worktribe.com/person/234634/rikesh-patel/outputs UoN repository] [http://eprints.nottingham.ac.uk/view/people/Patel=3ARikesh=3A=3A.html (old link)]
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==Journal publications==
 
==Journal publications==
  
 +
<bibtex>
 +
@article{leeSimpleMethodMeasuring2021,
 +
  title = {Simple Method of Measuring Thicknesses of Surface-Hardened Layers by Laser Ultrasonic Technique},
 +
  author = {Lee, Yong and Kitazawa, So and Patel, Rikesh},
 +
  year = {2021},
 +
  url = {https://iopscience.iop.org/article/10.35848/1347-4065/ac030f},
 +
  journal = {Jpn. J. Appl. Phys.},
 +
  issn = {0021-4922, 1347-4065},
 +
  doi = {10.35848/1347-4065/ac030f}
 +
}
 +
</bibtex>
  
 +
<bibtex>
 +
@article{patelSinglePixelCamera2021,
 +
  title = {Single Pixel Camera Methodologies for Spatially Resolved Acoustic Spectroscopy},
 +
  author = {Patel, Rikesh and Sharples, Steve D. and Clark, Matt and Somekh, Mike G. and Li, Wenqi},
 +
  year = {2021},
 +
  url = {https://aip.scitation.org/doi/10.1063/5.0040123},
 +
  journal = {Appl. Phys. Lett.},
 +
  volume = {118},
 +
  number = {5},
 +
  pages = {051102},
 +
  issn = {0003-6951, 1077-3118},
 +
  doi = {10.1063/5.0040123},
 +
  language = {en}
 +
}
 +
</bibtex>
  
 +
<bibtex>
 +
@article{brownNondestructiveDetectionMachininginduced2021a,
 +
  title = {Non-Destructive Detection of Machining-Induced White Layers through Grain Size and Crystallographic Texture-Sensitive Methods},
 +
  author = {Brown, M. and Pieris, D. and Wright, D. and Crawforth, P. and M'Saoubi, R. and McGourlay, J. and Mantle, A. and Patel, R. and Smith, R.J. and Ghadbeigi, H.},
 +
  year = {2021},
 +
  url = {https://linkinghub.elsevier.com/retrieve/pii/S0264127521000253},
 +
  journal = {Materials \& Design},
 +
  volume = {200},
 +
  pages = {109472},
 +
  issn = {02641275},
 +
  doi = {10.1016/j.matdes.2021.109472},
 +
  language = {en}
 +
}
 +
</bibtex>
 +
 +
<bibtex>
 +
@article{dryburgh_spatially_2019-1,
 +
  title = {Spatially Resolved Acoustic Spectroscopy for Integrity Assessment in Wire-Arc Additive Manufacturing},
 +
  author = {Dryburgh, Paul and Pieris, Don and Martina, Filomeno and Patel, Rikesh and Sharples, Steve and Li, Wenqi and Clare, Adam T. and Williams, Stewart and Smith, Richard J.},
 +
  year = {2019},
 +
  url = {https://linkinghub.elsevier.com/retrieve/pii/S2214860419302994},
 +
  journal = {Additive Manufacturing},
 +
  volume = {28},
 +
  pages = {236--251},
 +
  issn = {22148604},
 +
  doi = {10.1016/j.addma.2019.04.015},
 +
  language = {en}
 +
}
 +
</bibtex>
  
 +
<bibtex>
 +
@article{pieris_spatially_2019-1,
 +
  title = {Spatially Resolved Acoustic Spectroscopy Towards Online Inspection of Additive Manufacturing},
 +
  author = {Pieris, D and Patel, R and Dryburgh, P and Hirsch, M and Li, W and Sharples, S D and Smith, R J and Clare, A T and Clark, M},
 +
  year = {2019},
 +
  url = {https://www.ingentaconnect.com/content/10.1784/insi.2019.61.3.132},
 +
  journal = {Insight - Non-Destructive Testing and Condition Monitoring},
 +
  volume = {61},
 +
  number = {3},
 +
  pages = {132--137},
 +
  issn = {1354-2575},
 +
  doi = {10.1784/insi.2019.61.3.132},
 +
  language = {en}
 +
}
 +
</bibtex>
  
 
<bibtex>
 
<bibtex>
Line 168: Line 240:
 
<bibtex>
 
<bibtex>
 
@ARTICLE{Patel2011a,  author = {Rikesh Patel and Samuel Achamfuo-Yeboah and Roger Light and Matt Clark},  title = {Widefield heterodyne interferometry using a custom CMOS modulated light camera},  journal = {Opt. Express},  year = {2011},  volume = {19},  pages = {24546--24556},  number = {24},  month = {Nov},  abstract = {In this paper a method of taking widefield heterodyne interferograms using a prototype modulated light camera is described. This custom CMOS modulated light camera (MLC) uses analogue quadrature demodulation at each pixel to output the phase and amplitude of the modulated light as DC voltages. The heterodyne interference fringe patterns are generated using an acousto-optical frequency shifter (AOFS) in an arm of a Mach-Zehnder interferometer. Widefield images of fringe patterns acquired using the prototype MLC are presented. The phase can be measured to an accuracy of {\textpm}6.6{\textdegree}. The added value of this method to acquire widefield images are discussed along with the advantages.},  doi = {10.1364/OE.19.024546},  owner = {rp},  publisher = {OSA},  timestamp = {2012.01.13},  url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-19-24-24546}, pdf = {http://optics.eee.nottingham.ac.uk/w/images/d/d6/Pap1.pdf}}
 
@ARTICLE{Patel2011a,  author = {Rikesh Patel and Samuel Achamfuo-Yeboah and Roger Light and Matt Clark},  title = {Widefield heterodyne interferometry using a custom CMOS modulated light camera},  journal = {Opt. Express},  year = {2011},  volume = {19},  pages = {24546--24556},  number = {24},  month = {Nov},  abstract = {In this paper a method of taking widefield heterodyne interferograms using a prototype modulated light camera is described. This custom CMOS modulated light camera (MLC) uses analogue quadrature demodulation at each pixel to output the phase and amplitude of the modulated light as DC voltages. The heterodyne interference fringe patterns are generated using an acousto-optical frequency shifter (AOFS) in an arm of a Mach-Zehnder interferometer. Widefield images of fringe patterns acquired using the prototype MLC are presented. The phase can be measured to an accuracy of {\textpm}6.6{\textdegree}. The added value of this method to acquire widefield images are discussed along with the advantages.},  doi = {10.1364/OE.19.024546},  owner = {rp},  publisher = {OSA},  timestamp = {2012.01.13},  url = {http://www.opticsexpress.org/abstract.cfm?URI=oe-19-24-24546}, pdf = {http://optics.eee.nottingham.ac.uk/w/images/d/d6/Pap1.pdf}}
</bibtex>
 
 
==Proceedings ==
 
 
 
<bibtex>
 
@inproceedings{patel_widefield_2011-2,
 
  langid = {english},
 
  location = {{Toronto}},
 
  title = {Widefield Ultrastable Heterodyne Interferometry Using a Custom {{CMOS}} Modulated Light Camera},
 
  isbn = {978-1-55752-914-5},
 
  url = {https://www.osapublishing.org/abstract.cfm?URI=AOPT-2011-JWA14},
 
  doi = {10.1364/AOPT.2011.JWA14},
 
  booktitle = {Adaptive {{Optics}}: {{Methods}}, {{Analysis}} and {{Applications}}},
 
  booktitle = {Imaging and {{Applied Optics}}},
 
  publisher = {{OSA}},
 
  urldate = {2018-10-25},
 
  date = {2011},
 
  pages = {JWA14},
 
  author = {Patel, Rikesh and Clark, Matt and Achamfuo-Yeboah, Samuel},
 
  file = {/home/rp/Zotero/storage/HXL5XB6B/Patel et al. - 2011 - Widefield ultrastable heterodyne interferometry us.pdf}
 
}
 
</bibtex>
 
 
<bibtex>@inproceedings{p._dryburgh_targeted_2018,
 
  location = {{Edinburgh}},
 
  title = {Targeted Rework of Powder Bed Fusion Additive Manufacturing},
 
  url = {http://www.jlps.gr.jp/en/proc/lpm/18/},
 
  shorttitle = {Tue-3-{{OR15}}},
 
  abstract = {There is a clear industrial pull to fabricate high value components using premium high temperature aerospace materials by additive manufacturing. Inconveniently, the same  materials’ properties which allow them to perform well in service render them difficult to process  via powder bed fusion. Current build systems are characterised by high defect rates and erratic  microstructure, leading to components with inferior mechanical properties. Given the high specific costs in  powder bed fusion manufacture there is a real and apparent need to minimise component scrappage due to  these defects. Here a method is proposed to make good the defects that will inevitably be  produced in current class laser processing of metallic powders. This study investigates the use of spatially resolved acoustic  spectroscopy (SRAS) scan data to inform repair strategies within a commercial selective laser melting  machine. Using the common aerospace nickel superalloys, Inconel 718 and CM247-LC, localised remelting was shown to consistently reduce the depth of defect. A 50 \% reduction in defect depth  was observed for both materials using different rework strategies. No appreciable variation was seen  with the single-shot strategy, due inaccurate realignment.},
 
  booktitle = {19th {{International Symposium}} on {{Laser Precision Microfabrication}}},
 
  publisher = {{JLPS}},
 
  date = {0018-08-20},
 
  pages = {JLMN-18-089},
 
  author = {{P. Dryburgh} and {R. Patel} and {S. Catchpole-Smith} and {M. Hirsch} and {L. Perry} and {I. A. Ashcroft} and {A.T. Clare}}
 
}
 
 
</bibtex>
 
<bibtex>@inproceedings{don_milesh_pieris_spatially_2018,
 
  location = {{Nottingham}},
 
  title = {Spatially Resolved Acoustic Spectroscopy Additive Manufacturing – towards Online Inspection},
 
  url = {http://www.bindt.org/events/PastEvents/ndt-2018/},
 
  abstract = {High-integrity engineering applications such as aerospace will not  permit the incorporation of components containing any structural defects. The  current generation of additive manufacturing platforms yield components with relatively  high levels of defects. The in-line inspection of the components built using additive  can provide closed-loop feedback and vary build parameters during fabrication to  minimise such defects. This article reviews the capability of spatially resolved  acoustic spectroscopy to be used as an in-line inspection tool for detecting the changes in parts  induced due to variations in build parameters. The first considers the build laser  power and the second varies the laser scan strategy used to build the component. Using the  detected probe light intensity map and the measured surface acoustic velocity, the  detection of surface defects, subsurface defects and component microstructure can be measured.},
 
  booktitle = {57th {{The British Institue}} of {{Non}}-Destructive {{Testing Annual Conference}}},
 
  date = {0018-12-09},
 
  author = {{Don Milesh Pieris} and {Rikesh Patel} and {Paul Dryburgh} and {Matthias Hirsch} and {Wenqi Li} and {Steve D. Sharples} and {Richard J. Smith} and {Adam T. Clare} and {Matt Clark}}
 
}
 
 
</bibtex>
 
<bibtex>@inproceedings{paul_dryburgh_spatially_2018,
 
  location = {{Burlington VT}},
 
  title = {Spatially Resolved Acoustic Spectroscopy for Texture Imaging in Powder Bed Fusion Nickel Superalloys},
 
  abstract = {There is a clear industrial pull to fabricate high value components using premium high temperature aerospace materials by additive manufacturing. Inconveniently, the same material properties which allow them to perform well in service render them difficult to process via powder bed fusion. Current build systems are characterised by high defect rates and erratic microstructure, leading to components with inferior mechanical properties. The work presents microstructural texture imaging of powder-bed fusion components by a non-contact laser ultrasonic method, Spatially Resolved Acoustic Spectroscopy (SRAS). In short, this work demonstrates the ability to SRAS to detect and characterise meso-scale crystalline texture features. Probing samples manufactured by powder bed fusion, in the common nickel based aerospace superalloy Inconel 718, it has been shown the the primary crystalline orientation of can be inferred from the measured velocity, with good agreement with Electron Backscatter Diffraction. The studied sample was found to have a microstructure formation that bore a heavy resemblance to the chosen scanning pattern, with clear influence from the geometry through varying scan vector length and island-boundary scan strategy. this work forms part of a progression towards deployment of a SRAS system as an in-situ inspection solution for PBF.},
 
  booktitle = {45th {{Annual Review}} of {{Progress}} in {{Quantitative Nondestructive Evaluation}}},
 
  publisher = {{AIP Conference Proceedings}},
 
  date = {2018},
 
  author = {{Paul Dryburgh} and {Rikesh Patel} and {Don M. Pieris} and {Matthias Hirsch} and {Wenqi Li} and Steve D. Sharples and {Richard J. Smith} and {Adam T. Clare} and {Matt Clark}}
 
}
 
 
</bibtex>
 
<bibtex>@inproceedings{matt_clark_spatially_2018,
 
  location = {{Burlington VT}},
 
  title = {Spatially {{Resolved Acoustic Spectroscopy}} ({{SRAS}}) {{Microstructural Imaging}}},
 
  abstract = {Spatially resolved acoustic spectroscopy (SRAS) is an acoustic microscopy technique that can image the microstructure and measure the crystallographic orientation of grains or crystals in the material. It works by measuring the velocity of surface acoustic waves (SAWs) via the acoustic spectrum. In the usual configuration the SAWs are generated by laser using a pattern of lines and detected by laser close to this grating like source. The use of the acoustic spectrum as a means of measuring the velocity has a number of practical advantages which makes the technique robust and fast and gives good spatial resolution. This makes the measurement suitable for imaging and gives it many advantages over traditional laser UT and microstructural measurement techniques.
 
It works by measuring the velocity of surface acoustic waves (SAWs) via the acoustic spectrum. In the usual configuration the SAWs are generated by laser using a pattern of lines and detected by laser close to this grating like source. The use of the acoustic spectrum as a means of measuring the velocity has a number of practical advantages which makes the technique robust and fast and gives good spatial resolution. This makes the measurement suitable for imaging and gives it many advantages over traditional laser ultrasonic testing (LUT) and established microstructural measurement techniques.
 
As SRAS is a LUT technique is can be applied to a wide range of industrially relevant samples as a non-destructive evaluation technique. There are no size limitations on the samples that can be imaged and the surface preparation required is significantly more relaxed than many other techniques with the capability of operating on many as manufactured finishes. This permits the use of SRAS as an online inspection tool, for instance during additive or subtractive manufacturing, as a QA tool during manufacture or as an NDE/T tool in service.},
 
  booktitle = {45th {{Annual Review}} of {{Progress}} in {{Quantitative Nondestructive Evaluation}}},
 
  publisher = {{AIP Conference Proceedings}},
 
  date = {2018},
 
  author = {{Matt Clark} and {Adam Clare} and {Paul Dryburgh} and {Wenqi Li} and {Rikesh Patel} and {Don Pieris} and {Steve Sharples} and {Richard Smith}}
 
}
 
</bibtex>
 
 
==Conferences and Events ==
 
 
<bibtex>@techreport{rikesh_patel_custom_2010,
 
  venue = {{Nottingham (UK)}},
 
  title = {Custom {{CMOS}} Modulated Light Camera for Use in Aerospace Industry},
 
  abstract = {There is often the need to obtain a 3D image of a scene quickly. It is particularly useful in machine vision and in rover navigation. As shown in the figure above, the rover scans the area ahead of it and navigates appropriately. By using a low power camera array, it is possible to capture wide-field image maps with depth or distance information. Total power consumption is about 10W, and weight is under 1kg.
 
The CMOS camera works by using a sending a beam of modulated light to the target scene, and measuring the change in phase of the reflected light. Since time of flight is directly linked to the phase, it is possible to determine the range to the scene. By using an array of photo-detectors, it is possible to map the distance to several points in the scene quickly, and no scanning is required.},
 
  type = {Poster},
 
  institution = {University of {{Nottingham Institute}} of {{Aerospace Exposition}}},
 
  date = {2010-11-26},
 
  author = {{Rikesh Patel}, {Samuel Achamfuo-Yeboah, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_widefield_2011,
 
  venue = {{London (UK)}},
 
  title = {Widefield Heterodyne Interferometry Using a Custom {{CMOS}} Modulated Light Camera},
 
  abstract = {A method of detecting optical heterodyne interference fringes using a custom camera array has been developed. The custom CMOS modulated light camera (MLC) uses quadrature demodulation to output phase changes from detected modulated light as a DC voltage. The heterodyne interference fringe pattern is generated using an Acouto-optical frequency shifter in an arm of a Mach-Zehnder interferometer. Widefield images of fringe patterns acquired using the MLC are presented. Significance of using this method to acquire widefield images are discussed along with the advantages.},
 
  type = {Poster},
 
  institution = {3rd {{Intelligent Imaging Programme}}},
 
  date = {2011-03},
 
  author = {{Rikesh Patel}}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_widefield_2011-1,
 
  venue = {{Toronto (Canada)}},
 
  title = {Widefield Ultrastable Heterodyne Interferometry Using a Custom {{CMOS}} Modulated Light Camera},
 
  url = {https://www.osapublishing.org/abstract.cfm?URI=AOPT-2011-JWA14},
 
  abstract = {A method of detecting optical heterodyne interference fringes using a custom CMOS modulated light camera array has been developed. Widefield phase images are generated using quadrature demodulation and are kept stable using a feedback system.},
 
  type = {Poster},
 
  institution = {{{OSA Imaging}} and {{Applied Optics}} 2011},
 
  date = {2011-07-14},
 
  author = {{Rikesh Patel}, {Matt Clark, Samuel Achamfuo-Yeboah}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_widefield_2012,
 
  venue = {{Durham (UK)}},
 
  title = {Widefield Two-Laser Interferometer System Using a Modulated Light Camera},
 
  type = {Oral},
 
  institution = {{{IOP Photon12}}},
 
  date = {2012-07},
 
  author = {{Rikesh Patel}, {Samual Achamfuo-Yeboah, Roger Light, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_ultrasonic_2015,
 
  venue = {{Frejus (France)}},
 
  title = {Ultrasonic {{Inspection}} of {{Additive Manufactured Components}}},
 
  url = {https://intranet.sfa.asso.fr/archives/J87-AFPAC2015/},
 
  abstract = {Additive manufacturing (AM) is an important fabrication process in fields that include aerospace, automotive and medicine. Rapid prototypes of complex structures can be constructed using 3D metal printing; these structures will have high tensile strength that may not be constructed otherwise.
 
 
However, variations in the AM build process can affect the quality of the metal structure. Defects such as print warps, cracks, gaps and holes built into the structure (e.g. due to unconsolidated metal powder) can be difficult to detect visually. Changes to the build speed, the process order or the print technology could affect sections of the printed component; this unknown micro-structure can lead to unknown material performance. Laser ultrasonic inspection is an attractive technique for AM inspection as it is can cope with the complex form factors of AM parts.
 
 
SRAS (spatially resolved acoustic spectroscopy) is a method of characterising material though laser generated surface acoustic waves. The grain structures of AM metal parts can be imaged using this system, which would include information on the size and orientation of the grain; this can be used to ascertain the material strength. In addition, this technique can be used to detect the print porosity (e.g. gaps or errors).
 
 
Difficulties arise in performing laser ultrasound detection on optically rough samples; this paper presents work to date on capturing SRAS images of AM constructs. Images are taken of samples made using different 3D metal printing technologies including selective laser melting (SLM) and wire and arc additive manufacturing (WAAM). Whilst this is currently conducted offline, potentially, the presented inspection system could be performed in an online capacity as the components are printed, to verify mechanical properties and provide information to feed back into the build process.},
 
  type = {Oral},
 
  institution = {14th {{Anglo}}-{{French Physical Acoustics Conference}} ({{AFPAC2015}})},
 
  date = {2015-01-15},
 
  author = {{Rikesh Patel}, {Guangying Guan, Matthias Hirsch, Wenqi Li, Richard Smith, Samuel Achamfuo-Yeboah, Roger Light, Adam Clare, Christopher Tuck, Matt Clark, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{richard_smith_sras_2015,
 
  venue = {{Porton Down (UK)}},
 
  title = {{{SRAS UT Grain Measurement}}},
 
  type = {Oral},
 
  institution = {The {{Technical Cooperation Programme}} ({{TTCP}})},
 
  year = {05/Mar/2015},
 
  author = {{Richard Smith}, {Rikesh Patel, Guangying Guan, Matthias Hirsch, Wenqi Li, Samuel Achamfuo-Yeboah, Roger Light, Adam Clare, Christopher Tuck, Matt Clark, Steve Sharples}},
 
  editoratype = {collaborator},
 
  note = {Invited}
 
}
 
 
</bibtex> <bibtex>@techreport{adam_clare_ndt_2015,
 
  venue = {{Rotherham (UK)}},
 
  title = {{{NDT}} for {{AM}} – {{Research}} Efforts at the {{University}} of {{Nottingham}}},
 
  type = {Oral},
 
  institution = {{{BINDT Aerospace Event}}  2015},
 
  date = {2015-04},
 
  author = {{Adam Clare}, {Steve Sharples, Chris Tuck, Kristian Groom, Matthias Hirsch, Rikesh Patel, Wenqi Li, Richard Smith, Guangying Guan}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_using_2015,
 
  venue = {{Evanston IL (USA)}},
 
  title = {On Using Ultrasonic Non-Destructive Evaluation for Additive Manufactured Samples},
 
  abstract = {Additive manufacturing (AM) is an important fabrication process in fields such as aerospace, automotive and medicine.  Metal 3D printing is an emerging technology that allows for rapid prototyping of complex structures that can have high tensile strength and could not be constructed otherwise. However, variations in the AM build process can affect the quality of the metal structure. Defects such as print warps, cracks, gaps and holes built into the structure, i.e. due to unconsolidated metal powder, can be difficult to detect visually. Whilst in a complete print the micro-structure can be estimated statistically, changes to the build speed, the process order or the print technology could affect sections of the printed component; this unknown micro-structure can lead to unknown material performance or unwanted weaknesses.
 
 
Laser ultrasonic inspection is an attractive technique for AM inspection as it is can cope with the complex form factors of AM parts. Potentially, laser ultrasonic inspection could be performed online, as the components are printed, to verify mechanical properties and provide information to feed back into the build process.
 
 
SRAS (spatially resolved acoustic spectroscopy) is a method of characterising material though laser generated surface acoustic waves. The grain structures of AM metal parts can be imaged using this system, which would include information on the size and orientation of the grain; this can ultimately be used to ascertain the material stiffness. In addition, this technique can be used to detect the print porosity (e.g. gaps or errors). Difficulties arise in performing laser ultrasound detection on optically rough samples; this paper presents work to date on capturing SRAS images of the AM material from the speckle reflection. Images are taken of samples made using 3D metal printing technologies including selective laser melting (SLM) and wire and arc additive manufacturing (WAAM). Whilst this is currently conducted offline, the presented system illustrates a concept that could, in the future, be able to make measurements in an online capacity.},
 
  type = {Oral},
 
  institution = {4th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2015}})},
 
  date = {0015-06-28},
 
  author = {{Rikesh Patel}, {Matthias Hirsch, Wenqi Li, Richard Smith, Samuel Achamfuo-Yeboah, Chris Tuck, Matt Clark, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{jethro_coulson_non-destructive_2015,
 
  venue = {{Minneapolis MN (USA)}},
 
  title = {Non-{{Destructive Evaluation}} for {{Additive Manufacturing}}},
 
  url = {https://www.qndeprograms.org/sites/default/files/2015-abstract_1.pdf},
 
  abstract = {Additive manufacturing (AM) is an important fabrication process in fields that include aerospace, automotive and medicine. Rapid prototypes of complex structures can be constructed using 3D metal printing; these structures will have high tensile strength that may not be constructed otherwise.
 
However, variations in the AM build process can affect the quality of the metal structure. Defects such as print warps, cracks, gaps and holes built into the structure (e.g. due to unconsolidated metal powder) can be difficult to detect visually. Changes to the build speed, the process order or the print technology could affect sections of the printed component; this unknown micro-structure can lead to unknown material performance. Laser ultrasonic inspection is an attractive technique for AM inspection as it is can cope with the complex form factors of AM parts.
 
 
SRAS (spatially resolved acoustic spectroscopy) is a method of characterising material though laser generated surface acoustic waves. The grain structures of AM metal parts can be imaged using this system, which would include information on the size and orientation of the grain; this can be used to ascertain the material strength. In addition, this technique can be used to detect the print porosity (e.g. gaps or errors).
 
Difficulties arise in performing laser ultrasound detection on optically rough samples; this paper presents work to date on capturing SRAS images of AM constructs. Images are taken of samples made using different 3D metal printing technologies including selective laser melting (SLM) and wire and arc additive manufacturing (WAAM). Whilst this is currently conducted offline, potentially, the presented inspection system could be performed in an online capacity as the components are printed, to verify mechanical properties and provide information to feed back into the build process.},
 
  type = {Oral},
 
  institution = {42nd {{Annual Review}} of {{Progress}} in {{Quantitative Nondestructive Evaluation}} ({{42QNDE}})},
 
  date = {2015-07-26},
 
  author = {{Jethro Coulson}, {Rikesh Patel, Steve Sharples, Adam Clare, Wenqi Li, Richard Smith, Matthias Hirsch, Chris Tuck, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{steve_sharples_rcnde_2015,
 
  venue = {{Manchester (UK)}},
 
  title = {{{RCNDE}}: {{NDE}} for {{Additive Manufacturing Research Review}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Research Review Meeting}}},
 
  date = {2015-04-22},
 
  author = {{Steve Sharples}, {Adam Clare, Matt Clark, Chris Tuck, Richard Smith, Rikesh Patel, Guangying Guan, Matthias Hirsch, Wenqi Li, Preetha Malla}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_laser_2016,
 
  venue = {{Linz (Austria)}},
 
  title = {Laser Ultrasonic Inspection of  As-Deposited {{AM}} Samples},
 
  url = {https://www.recendt.at/de/lu2016.html},
 
  abstract = {The use of additive manufacturing (AM) for production of performance parts as well as for rapid prototyping is of interest for those in the aerospace, construction and medical fields. This emerging manufacturing route has a major advantage over more traditional methods as it allows for complex designs that may not be produced any other way. The process, also commonly known as 3D printing, can utilise a variety of materials – metal alloy printed parts can be extremely useful as they can endure high strain and temperature. However, the performance limit of the parts will depend largely on the print quality – this would include structural defects (e.g. pores, cracks, delamination) as well as part non-conformities (e.g. design errors, size errors, inappropriate micro-structure). To discover any potential part weaknesses, a non-destructive, non-contact inspection method would be ideal, especially if it is practical to implement into a printer in order to inspect parts in-situ (as it is being printed).
 
Spatially resolved acoustic spectroscopy (SRAS) is a method of characterising material though laser generated surface acoustic waves (SAW) - it has been used to map metal grain structures using SAW velocity measurement[1]. The method can also be used to detect defects (e.g signal attenuation or significant change in velocity)[2]. The established SRAS detection system requires a smooth surface finish (Ra$<$100nm) - the surface roughness of an as-deposited part is much higher (Ra$>$3μm).
 
In this paper, we present our solution of measuring the surface acoustic wave generated on an as-deposited AM part. The SAW is measured using the speckle reflection off the optically rough surface, captured using a speckle knife edge detector (SKED)(figure 1). The mapped SAW velocities measured off the AM part in a 2D scan will be presented – the link between print parameters and print quality will be illustrated. Mapping the characteristics of an as-deposited part in a timely and non invasive manner is a critical improvement to the AM technology.},
 
  type = {Oral},
 
  institution = {5th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2016}})},
 
  year = {02/July/2016},
 
  author = {{Rikesh Patel}, {Matthias Hirsch, Wenqi Li, Richard Smith, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{victoria_ageeva_control_2016,
 
  venue = {{Linz (Austria)}},
 
  title = {Control of the {{Rayleigh}} Wave Propagation with a Resonant Metawedge: A Practical Concept Demonstration of Seismic Metamaterials},
 
  url = {https://www.recendt.at/de/lu2016.html},
 
  abstract = {The use of additive manufacturing (AM) for production of performance parts as well as for rapid prototyping is of interest for those in the aerospace, construction and medical fields. This emerging manufacturing route has a major advantage over more traditional methods as it allows for complex designs that may not be produced any other way. The process, also commonly known as 3D printing, can utilise a variety of materials – metal alloy printed parts can be extremely useful as they can endure high strain and temperature. However, the performance limit of the parts will depend largely on the print quality – this would include structural defects (e.g. pores, cracks, delamination) as well as part non-conformities (e.g. design errors, size errors, inappropriate micro-structure). To discover any potential part weaknesses, a non-destructive, non-contact inspection method would be ideal, especially if it is practical to implement into a printer in order to inspect parts in-situ (as it is being printed).
 
Spatially resolved acoustic spectroscopy (SRAS) is a method of characterising material though laser generated surface acoustic waves (SAW) - it has been used to map metal grain structures using SAW velocity measurement[1]. The method can also be used to detect defects (e.g signal attenuation or significant change in velocity)[2]. The established SRAS detection system requires a smooth surface finish (Ra$<$100nm) - the surface roughness of an as-deposited part is much higher (Ra$>$3μm).
 
In this paper, we present our solution of measuring the surface acoustic wave generated on an as-deposited AM part. The SAW is measured using the speckle reflection off the optically rough surface, captured using a speckle knife edge detector (SKED)(figure 1). The mapped SAW velocities measured off the AM part in a 2D scan will be presented – the link between print parameters and print quality will be illustrated. Mapping the characteristics of an as-deposited part in a timely and non invasive manner is a critical improvement to the AM technology.},
 
  type = {Poster},
 
  institution = {5th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2016}})},
 
  year = {02/July/2016},
 
  author = {{Victoria Ageeva}, {Andrea Colombi, Adam Clare, Richard V. Craster, Rikesh Patel, Richard Smith, Matt Clark}},
 
  editoratype = {collaborator},
 
  note = {Student prize winner (1st)}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_rcnde_2016,
 
  venue = {{Manchester (UK)}},
 
  title = {{{RCNDE}}: {{Laser}} Ultrasonic Inspection of  as-Deposited {{AM}} Samples},
 
  type = {Oral},
 
  institution = {{{RCNDE Early Stage Researchers Event}} 2016},
 
  date = {2016-07},
 
  author = {{Rikesh Patel}}
 
}
 
 
</bibtex> <bibtex>@techreport{a._clare_-process_2016,
 
  venue = {{Guimaraes (Portugal)}},
 
  title = {In-{{Process Monitoring}} of {{Additive Layer Manufacturing}}},
 
  url = {https://cirp2016.org/},
 
  abstract = {Additive layer manufacturing methods are renowned for generating parts with defects that are difficult to detect and resulting part integrity is therefore difficult to predict. Post process, non-destructive evaluation is currently used to assess this but an improved solution is to embed measurement apparatus within machine tools in order to continually evaluate performance in process.
 
This presentation will provide an insight into ongoing work which makes use of two techniques; optical coherence tomography (OCT) and Spatially Resolved Acoustic Spectroscopy (SRAS) for polymer and metal ALM methods respectively. Both of these techniques are of significant interest to machine builders since they are able to evaluate both surface and subsurface integrity. Through the use of OCT it is possible to discriminate between the density of subsurface regions within the near surface 500µm of Nylon 12 SLS specimen. In addition the use of SRAS is shown to detect surface pores alongside correlating crack densities with laser scan strategies. The use of these tools also presents new opportunities for inspection and discussion will also focus on how they will be used in the industrial setting.},
 
  type = {Oral},
 
  institution = {{{CIRP}} 66th {{General Assembly}} ({{CIRP}} 2016)},
 
  date = {2016-08-21},
 
  author = {{A. Clare}, {S. Sharples, R. Leach, G. Guan, M. Hirsch, R. Patel}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_rcnde_2016-1,
 
  venue = {{Nottingham (UK)}},
 
  title = {{{RCNDE}}: {{Inspection}} of Additive Manufacture Parts Using {{SRAS}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Industrial Working Group Visit}} 2016},
 
  date = {2016-09-14},
 
  author = {{Rikesh Patel}, {Wenqi Li, Matthias Hirsch, Richard Smith, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_using_2016,
 
  venue = {{Nottingham (UK)}},
 
  title = {Using Spatially Resolved Acoustic Spectroscopy ({{SRAS}}) on {{AM}} Produced Parts},
 
  url = {http://optics.eee.nottingham.ac.uk/w/images/7/76/Optics%2Bultrasound_abstracts.pdf},
 
  type = {Oral},
 
  institution = {{{IOP Optics}}+{{Ultrasound III}}},
 
  year = {09/Nov/2016},
 
  author = {{Rikesh Patel}, {Wenqi Li, Paul Marrow, Matthias Hirsch, Richard Smith, Adam Clare, Steve Sharples, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{adam_t._clare_approaches_2017,
 
  venue = {{Hanover (Germany)}},
 
  title = {Approaches for {{AM}} In-Process Inspection Using {{SRAS}} and {{OCT}}},
 
  url = {https://www.euspen.eu/events/17th-international-conference-exhibition/},
 
  type = {Oral},
 
  institution = {{{EUSPEN}} 17th {{International Conference}} \& {{Exhibition}}},
 
  date = {2017-01-23},
 
  author = {{Adam T. Clare}, {Matthias Hirsch, Guanying Guan, Rikesh Patel, Wenqi Li, Paul Dryburgh, Don Pieris, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_rcnde_2017,
 
  venue = {{Warwick (UK)}},
 
  title = {{{RCNDE}}: {{Additive Manufacturing}} and the Role of {{NDE}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Technology Transfer Event}} 2017},
 
  date = {2017-01-30},
 
  author = {{Rikesh Patel}, {Wenqi Li, Matthias Hirsch, Richard Smith, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_rcnde_2017-1,
 
  venue = {{Warwick (UK)}},
 
  title = {{{RCNDE}}: {{SRAS}} Live Demonstration},
 
  type = {Demonstration},
 
  institution = {{{RCNDE Technology Transfer Event}} 2017},
 
  date = {2017-01-30},
 
  author = {{Rikesh Patel}, {Wenqi Li, Matthias Hirsch}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{steve_sharples_rcnde_2017,
 
  venue = {{Bristol (UK)}},
 
  title = {{{RCNDE}}: {{NDE}} for {{Additive Manufacturing Research Review}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Research Review Meeting}}},
 
  year = {10/May/2017},
 
  author = {{Steve Sharples}, {Adam Clare, Matt Clark, Chris Tuck, Richard Smith, Matthias Hirsch, Rikesh Patel, Wenqi Li, Paul Dryburgh, Don Milesh Pieris}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{adam_clare_rcnde_2016,
 
  venue = {{Glasgow (UK)}},
 
  title = {{{RCNDE}}: {{NDE}} for {{Additive Manufacturing Research Review}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Research Review Meeting}}},
 
  date = {2016-04-27},
 
  author = {{Adam Clare}, {Steve Sharples, Matt Clark, Chris Tuck, Richard Smith, Matthias Hirsch, Rikesh Patel, Wenqi Li}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_sked---box_2017,
 
  venue = {{Telford (UK)}},
 
  title = {{{SKED}}-{{In}}-a-Box},
 
  url = {http://www.bindt.org/events/Materials-Testing-2017/},
 
  type = {Demonstration},
 
  institution = {{{BINDT MT2017}}},
 
  year = {05/Sept/2017},
 
  author = {{Rikesh Patel}, {Don Pieris, Paul Dryburgh, Matthias Hirsch, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{don_milesh_pieris_non-destructive_2017,
 
  venue = {{Derby (UK)}},
 
  title = {Non-{{Destructive Evaluation}} of {{Additive Layer Manufactured Component Microstructure}}},
 
  type = {Oral},
 
  institution = {Rolls {{Royce EngD Conference}} 2017},
 
  year = {01/Nov/2017},
 
  author = {{Don Milesh Pieris}, {Sam Catchpole-Smith, Matt Clark, Adam Clare, Steve Sharples, Rikesh Patel, Wenqi Li, Richard Smith}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_sked---box_2017-1,
 
  venue = {{Derby (UK)}},
 
  title = {{{SKED}}-{{In}}-a-Box},
 
  type = {Demonstration},
 
  institution = {Rolls {{Royce EngD Conference}} 2017},
 
  year = {01/Nov/2017},
 
  author = {{Rikesh Patel}, {Don Pieris, Paul Dryburgh, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_sked---box_2017-2,
 
  venue = {{Glasgow (UK)}},
 
  title = {{{SKED}}-in-a-Box: A Simple and Inexpensive Laser Ultrasound Rough Surface Detector System},
 
  url = {https://www.iopconferences.org/iop/frontend/reg/thome.csp?pageID=678826&eventID=1164&CSPCHD=000001000000AloUgmZfeAXt5VsIDeO4NDxg9AYd5_fuJaW_4h},
 
  abstract = {The advantages of using laser ultrasound (LU) to conduct non-destructive material evaluation includes the ability to perform non-contact testing and measure small features. However LU is not often used in an industrial environment due to some detection drawbacks. The detection system may not be robust enough under microphonics/vibration. Given the industrial context, it is difficult to detect ultrasonic signals on surfaces that give specular return (rough surfaces). Finally, commercial detector solutions are often too expensive and restrictive for the technique to be used outside niche scenarios.
 
This presentation will explore the detector known as the speckle knife edge detector (SKED), which can potentially overcome all these drawbacks. The detector is able to measure an incident speckle field shift, i.e. measure ultrasound signals off rough surfaces. There are some key benefits in using the SKED, including the cost, speed and small form factor. A demonstration of a SKED experiment is planned.},
 
  type = {Oral},
 
  institution = {{{IOP Optics}}+{{Ultrasound IV}}},
 
  year = {23/Nov/2017},
 
  author = {{Rikesh Patel}, {Samuel Achamfuo-Yeboah, Don Milesh Pieris, Roger Light, Steve Sharples, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{don_milesh_pieris_detection_2017,
 
  venue = {{Glasgow (UK)}},
 
  title = {Detection of the Manipulation of Additively Manufactured Component Microstructure Using Spatially Resolved Acoustic Spectroscopy},
 
  url = {https://www.iopconferences.org/iop/frontend/reg/thome.csp?pageID=678826&eventID=1164&CSPCHD=000001000000AloUgmZfeAXt5VsIDeO4NDxg9AYd5_fuJaW_4h},
 
  abstract = {Most additive manufacturing (AM) techniques such as selective laser melting yield columnar grains in the build direction (Z). An instrument capable of detecting and which could be used to control the component micro-structure would revolutionise the AM build process. This would open up a wide range of applications for the manufacture of high-performance components such as turbine blades where the microstructure is crucial to the mechanical properties.
 
Spatially Resolved Acoustic Spectroscopy (SRAS) has been used to image the microstructure of large-grained materials such as titanium. This talk explores the uses of SRAS to detect changes in an AM components texture in the XY plane. This is followed by an outline of experiments which aim to detect the influence of different scan strategies and demonstrate control over the microstructure along the build direction of a component.},
 
  type = {Oral},
 
  institution = {{{IOP Optics}}+{{Ultrasound IV}}},
 
  year = {23/Nov/2017},
 
  author = {{Don Milesh Pieris}, {Rikesh Patel, Matthias Hirsch, Paul Dryburgh, Sam Catchpole-Smith, Steve Sharples, Wenqi Li, Richard Smith, Adam Clare, Matt Clark}},
 
  editoratype = {collaborator},
 
  note = {Winner student prize}
 
}
 
 
</bibtex> <bibtex>@techreport{paul_dryburgh_detecting_2017,
 
  venue = {{Glasgow (UK)}},
 
  title = {Detecting and Characterising Subsurface Porosity in {{Selective Laser Melting}} ({{SLM}}) Components Using Laser Ultrasound},
 
  url = {https://www.iopconferences.org/iop/frontend/reg/thome.csp?pageID=678826&eventID=1164&CSPCHD=000001000000AloUgmZfeAXt5VsIDeO4NDxg9AYd5_fuJaW_4h},
 
  abstract = {Selective Laser Melting (SLM) is a form of additive manufacturing used to build complex geometrical shapes in a layer-by-layer process from a powder feedstock. SLM manufactured components have promising uses for high value industries such as medical, aerospace and tooling, however the process is inherently prone to defects and combined with a lack of robust suitable inspection techniques, uptake in safety critical applications has been limited. By inspecting in-situ on a layer-by-layer basis a 3D model of the component integrity could be developed, this theme is extended to present an overview of the opportunities offered by in-situ inspection along with the requirements of a suitable technique, including the ability to interrogate the subsurface. The ability to detect subsurface porosity using the Spatially Resolved Acoustic Spectroscopy (SRAS) laser ultrasound technique, and further quantify this data using dispersive Lamb waves shall be explored.},
 
  type = {Oral},
 
  institution = {{{IOP Optics}}+{{Ultrasound IV}}},
 
  year = {23/Nov/2017},
 
  author = {{Paul Dryburgh}, {Rikesh Patel, Matthias Hirsch, Don Milesh Pieris, Wenqi Li, Richard Smith, Matt Clark, Adam Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{wenqi_li_orientation_2017,
 
  venue = {{Glasgow (UK)}},
 
  title = {Orientation Imaging of Polysilicon Grains Using Spatially Resolved Acoustic Spectroscopy},
 
  url = {https://www.iopconferences.org/iop/frontend/reg/thome.csp?pageID=678826&eventID=1164&CSPCHD=000001000000AloUgmZfeAXt5VsIDeO4NDxg9AYd5_fuJaW_4h},
 
  abstract = {Solar panel is a key component for renewable energy industry; the polysilicon, also called multicrystalline silicon, is widely used to produce solar cell wafers. However, as the structure and orientation strongly linked to conversion effiencies, polysilicon are often less efficient than equivalent mono crystalline or thin film cells. The capability of a non-destructive laser ultrasonic inspection technique spatially resolved acoustic spectroscopy (SRAS) is presented for characterising silicon cell wafer's microstructure and grains orientation; scanning times, sample surface preparation and system upgrades for silicon measurement are also discussed. This technique could be used to optimise the polysilicon wafer production process and potentially improve effciency.},
 
  type = {Oral},
 
  institution = {{{IOP Optics}}+{{Ultrasound IV}}},
 
  year = {23/Nov/2017},
 
  author = {{Wenqi Li}, {R. Patel, R. J. Smith, M. Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{p_dryburgh_rcnde_2018,
 
  venue = {{London (UK)}},
 
  title = {{{RCNDE}}: {{Laser}} Ultrasound for Additive Manufacturing Defects},
 
  type = {Poster},
 
  institution = {{{RCNDE Technology Transfer Event}} 2018},
 
  date = {2018-01-29},
 
  author = {{P Dryburgh}, {DM Pieris, R Patel, W Li, R Smith, M Clark, AT Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{don_m_pieris_rcnde_2018,
 
  venue = {{London (UK)}},
 
  title = {{{RCNDE}}: {{Observing Defects}} and {{Microstructure}} in {{Additively Manufactured Components}}},
 
  type = {Poster},
 
  institution = {{{RCNDE Technology Transfer Event}} 2018},
 
  date = {2018-01-29},
 
  author = {{Don M Pieris}, {Rikesh Patel, Richard J Smith, Wenqi Li, Adam Clare, Matt Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{matt_clark_finding_2018,
 
  venue = {{Sheffield (UK)}},
 
  title = {Finding and {{Fixing Defects}} in {{Metal Powder Bed Processes}}},
 
  url = {https://mapp.ac.uk/events/mapp-1st-international-conference},
 
  abstract = {High integrity engineering applications will not permit the incorporation of many defects observed in current class powder bed fabrication systems. Therefore, there are limitations as to which engineering context this manufacturing method may be used. Ex-situ methods of inspection and verification will always be necessary for quality control but, current commercial techniques can undermine the business case for using additive manufacturing. Undertaking in process geometrical measurements, condition monitoring and intra layer integrity evaluation are therefore key aspects for pushing additive manufacturing forward and assuring that parts are of the required quality. The advancement of new instruments also allows for the inspection of additional facets of the additive manufacturing process such a re-coater performance, crystal grain size, orientation and raster scan efficacy. The ability to identify early warning signs of failure is critical in order to pause a failing or failed build to save expensive raw materials and machine time.
 
Beyond identification of defects, next generation machine tools will be able to propose and execute repair strategies to some classifications of defects once observed. This will represent a step change in machine tool technology and will serve to open numerous applications for additive manufacturing. This talk will firstly address the rapidly shifting state-of-the-art in this area focusing on metal/polymer powder bed fabrication methodologies. Techniques for comparing in-process evaluation apparatus will be discussed with respect to assessing the spatial and temporal capability of a given instrument. Instruments being developed at the University of Nottingham for in process metrology and monitoring will be presented. Typical data sets created by these will be introduced and capability examined. The method of machine integration and reasonable expectations as a result of future developments will be discussed. In addition recent advances at Nottingham will be introduced which highlight a new methodology for detecting and repairing cracks and pores produced in metal powder bed systems. Activities supported through European and EPSRC initiative will also be explored. These include in-process fringe projection/ photogrammetry techniques, a two-sensor approach to process optimization, a multi-sensor fusion approach for metal powder-bed fusion, laser ultrasonics and optical coherence tomography.},
 
  type = {Oral},
 
  institution = {1st {{Manufacturing}} Using {{Advanced Powder Processes Conference}} ({{MAPP}})},
 
  date = {2018-01-30},
 
  author = {{Adam Clare}, {Matt Clark, Steve Sharples, Richard Smith, Wenqi Li, Rikesh Patel, Paul Dryburgh, Don Milesh Pieris}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{adam_clare_healing_2018,
 
  venue = {{Phoenix AZ (USA)}},
 
  title = {Healing {{Defects}} within {{Powder Bed Fabrication}}},
 
  url = {https://www.tms.org/tms2018},
 
  type = {Oral},
 
  institution = {{{TMS}} 147th {{Annual Meeting}} and {{Exhibition}} ({{TMS2018}})},
 
  date = {2018-03-14},
 
  author = {{Adam Clare}, {Richard Leach, Ian Ashcroft, Matthias Hirsch, Rikesh Patel, Steve Sharples}},
 
  editoratype = {collaborator},
 
  note = {Invited}
 
}
 
 
</bibtex> <bibtex>@techreport{adam_clare_rcnde_2018,
 
  venue = {{Manchester (UK)}},
 
  title = {{{RCNDE}}: {{NDE}} for {{Additive Manufacturing Research Review}}},
 
  type = {Oral},
 
  institution = {{{RCNDE Research Review Meeting}}},
 
  year = {02/May/2018},
 
  author = {{Adam Clare, Rikesh Patel}, {Matt Clark, Chris Tuck, Richard Smith, Wenqi Li, Paul Dryburgh, Don Milesh Pieris}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{wenqi_li_spatially_2017,
 
  venue = {{Provo UT (USA)}},
 
  title = {Spatially Resolved Acoustic Spectroscopy ({{SRAS}}): Texture and Microstructure Characterisation},
 
  url = {https://www.qndeprograms.org/events/44th-annual-review-of-progress-in-quantitative-nondestructive-evaluation/},
 
  type = {Oral},
 
  institution = {World {{Federation}} of {{NDE Centers Short Course}} 2017},
 
  date = {2017-07-14},
 
  author = {{Wenqi Li}, {Rikesh Patel, Richard Smith, Matthias Hirsch, Matt Clark, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator},
 
  note = {Invited}
 
}
 
 
</bibtex> <bibtex>@techreport{matt_clark_spatially_2018-1,
 
  venue = {{Bristol (UK)}},
 
  title = {Spatially {{Resolved Acoustic Spectroscopy}} ({{SRAS}}) and {{NDE}} for {{Additively}} Manufactured Components},
 
  url = {http://www.bindt.org/events/PastEvents/aerospace-workshop-2018-past/},
 
  type = {Oral},
 
  institution = {{{BINDT Aerospace Event}}  2018},
 
  year = {10/Apr/2018},
 
  author = {{Rikesh Patel}, {Matt Clark, Adam Clare, Steve Sharples, Richard Smith, Wenqi Li, Paul Dryburgh, Don Milesh Pieris}},
 
  editoratype = {collaborator},
 
  note = {Invited + Panel invite}
 
}
 
 
</bibtex> <bibtex>@techreport{paul_dryburgh_targeted_2018,
 
  venue = {{Edinburgh (UK)}},
 
  title = {Targeted {{Rework}} of {{Powder Bed Fusion Additive Manufacturing}}},
 
  url = {http://www.jlps.gr.jp/en/proc/lpm/18/},
 
  abstract = {There is a clear industrial pull to fabricate high value components using premium high temperature aerospace materials by additive manufacturing. Inconveniently, the same material properties which allow them to perform well in service render them difficult to process via powder bed fusion. Current build systems are characterised by high defect rates and erratic microstructure, leading to components with inferior mechanical properties. Given the high specific costs in powder bed fusion manufacture there is a real and apparent need to minimise component scrappage due to these defects. Here a method is proposed to make good the defects that will inevitably be produced in current class laser processing of metallic powders.
 
This study investigates the use of spatially resolved acoustic spectroscopy (SRAS) scan data to inform repair strategies within a commercial selective laser melting machine.  Using the common aerospace nickel superalloys, Inconel 718 and CM247-LC, localised re-melting was shown to consistently reduce the depth of defect. A 50 \% reduction in defect depth was observed for both materials using different rework strategies. No appreciable variation was seen with the single-shot strategy, due inaccurate realignment.},
 
  type = {Oral},
 
  institution = {19th {{International Symposium}} on {{Laser Precision Microfabrication}}},
 
  date = {2018-06-26},
 
  author = {{Paul Dryburgh}, {Rikesh Patel, Sam Catchpole-Smith, Matthias Hirsch, Luke Parry, Richard J Smith, Matt Clark, Ian A Ashcroft, Adam T Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{r_patel_non-destructive_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {Non-Destructive Evaluation of Additively Manufactured Materials –towards Online Inspection for Selective Laser Melting},
 
  url = {http://lu2018.iopconfs.org/home},
 
  abstract = {Selective laser melting (SLM) is an additive manufacturing (AM) technique used to build parts layer-by-layer by fusing metallic power. The parts can have complex geometries which cannot be made using traditional manufacturing methods. The AM process consists of uncontrollable build variables which can often lead to the development of defects and part non-conformities. To certify parts for operation in tough or safety critical environments every part must be inspected. 
 
We are developing in-situ ultrasonic inspection techniques to assess build quality during the build process. This will allow for closed-loop smart fabrication systems, where detected flaws can cause used to stop entire build processes (saving time and material) or be used to correctively rework the flaw. 
 
The proposed laser ultrasound technique can be used to detected both surface and subsurface defects, and can be
 
used to inspect the material microstructure or texture. Working on as-deposited SLM material is challenging due to the high surface roughness. We will present results of the laser ultrasonic technique – spatially resolved acoustic spectroscopy (SRAS) – on as deposited material from a build chamber compatible instrument. We will discuss the possibilities for defect and microstructure control, and the challenges remaining for online inspection.
 
This work was supported by the research centre for nondestructive evaluation (RCNDE) [EP/L022125/1]},
 
  type = {Oral},
 
  institution = {6th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2018}})},
 
  year = {09/July/2018},
 
  author = {{R Patel}, {P Dryburgh, D Pieris, W Li, R Smith, A Clare, M Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_rcnde_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {{{RCNDE}}: {{Spatially}} Resolved Acoustic Spectroscopy ({{SRAS}}) Inspection on as-Deposited Selective Laser Melted ({{SLM}}) Builds},
 
  type = {Poster},
 
  institution = {{{RCNDE Early Stage Researchers Event}} 2018},
 
  date = {2018-06-18},
 
  author = {{Rikesh Patel}, {Matthias Hirsch, Paul Dryburgh, Don M. Pieris, Wenqi Li, Richard Smith, Matt Clark, Adam Clare, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{wenqi_li_rcnde_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {{{RCNDE}}: {{Orientation Imaging}} of {{Polysilicon Grains Using Spatially Resolved Acoustic Spectroscopy}}},
 
  type = {Poster},
 
  institution = {{{RCNDE Early Stage Researchers Event}} 2018},
 
  date = {2018-06-18},
 
  author = {{Wenqi Li}, {Rikesh Patel, Richard Smith, Matt Clark, Steve Sharples}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{p_dryburgh_making_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {Making and Utilising Online Measurements by Laser Ultrasound in Powder Bed Additive Manufacturing},
 
  url = {http://lu2018.iopconfs.org/home},
 
  abstract = {Selective Laser Melting (SLM) is an exciting prospect for use in high-value manufacturing. Removing many of traditional machining constraints allows significant design optimisation and weight-saving, however defects levels found in current class build systems is not acceptable for structural components. The complex geometry found in SLM posses many challenges for traditional NDT techniques. The layer-by-layer manufacturing nature provides an opportunity to take surface measurements to develop volumetric datasets, whilst circumventing many of the problems posed by novel, geodesic structures. Additionally, traditional fabrication techniques have undergone centuries of refinement, allowing close control of the final crystalline micro-structure, dictating the mechanical performance. In contrast, additive manufacturing is characterised by highly isotropic and difficult to control microstructure. Given the impact on the functional properties of the component, techniques which can provide microstucture information are highly valuable. The high associated costs with SLM, compared to both other additive and subtractive techniques encourages a minimisation of scrapped builds, current linear work flows rely on post-build inspection and subsequently significant numbers of failed builds. Whilst online monitoring can allow early scrappage, true value shall be added through the realisation of adaptive scan strategies to correct defects as they arise.
 
Spatially Resolved Acoustic Spectroscopy (SRAS) is an acoustic microscopy technique, which utilises laser ultrasonics for the excitation and detection of surface acoustic waves for materials characterisation. This technique meets many of the requirements of a suitable inspection technique for SLM, such as non-destructive, and early studies have confirmed the ability to detect defects and measure microstructure in SLM parts using SRAS. However, significant challenges remain as the technique and instrumentation is developed towards online measurements. This talk will discuss the merits of using SRAS for in-process inspection for defect detection and characterisation, with a review to enabling remedial action. Discussion will touch on system capability, including a time-cost model and progress towards build system integration. Particular focus will be paid to the detection and characterisation of porosity, both subsurface and surface breaking.},
 
  type = {Oral},
 
  institution = {6th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2018}})},
 
  year = {09/July/2018},
 
  author = {{P Dryburgh}, {D M Pieris, R Patel, W Li, R J Smith, M Clark, A T Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{w_li_orientation_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {Orientation Imaging of Polysilicon Grains Using Spatially Resolved Acoustic Spectroscopy},
 
  url = {http://lu2018.iopconfs.org/home},
 
  abstract = {Solar panel is a key component for renewable energy industry; the polysilicon, also called multicrystalline silicon, is widely used to produce solar cell wafers. However, as the structure and orientation strongly linked to conversion efficiencies, polysilicon are often less efficient than equivalent monocrystalline or thin film cells. The capability of a non-destructive laser ultrasonic inspection technique -- spatially resolved acoustic spectroscopy (SRAS) – is presented for characterising silicon cell wafer's microstructure and grains orientation; scanning times, sample surface preparation and system upgrades for silicon measurement are also discussed. This technique could be used to optimise the polysilicon wafer production process and potentially improve efficiency},
 
  type = {Oral},
 
  institution = {6th {{International Symposium}} on {{Laser Ultrasonics}} ({{LU2018}})},
 
  year = {09/July/2018},
 
  author = {{W Li}, {R Patel, R J Smith, M Clark}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_laser_2018,
 
  venue = {{Burlington VT (USA)}},
 
  title = {Laser Ultrasound in Additive Manufacture: Overcoming the Rough Surface Challenge},
 
  url = {https://register.extension.iastate.edu/qnde/program/wfnde-short-course},
 
  type = {Oral},
 
  institution = {World {{Federation}} of {{NDE Centers Short Course}} 2018},
 
  date = {2018-07-15},
 
  author = {{Rikesh Patel}},
 
  note = {Invited}
 
}
 
 
</bibtex> <bibtex>@techreport{rikesh_patel_non-destructive_2018,
 
  venue = {{Burlington VT (USA)}},
 
  title = {Non-{{Destructive Evaluation}} of {{Additively Manufactured Materials}} - towards Online Inspection for {{Selective Laser Melting}}},
 
  url = {https://register.extension.iastate.edu/qnde},
 
  abstract = {Selective laser melting (SLM) is an additive manufacturing (AM) technique used to build parts layer-by-layer by fusing metallic power. The parts can have complex geometries which cannot be made using traditional manufacturing methods. The AM process consists of uncontrollable build variables which can often lead to the development of defects and part non-conformities. To certify parts for operation in tough or safety critical environments every part must be inspected.
 
We are developing in-situ ultrasonic inspection techniques to assess build quality during the build process. This will allow for closed-loop smart fabrication systems, where detected flaws can cause used to stop entire build processes (saving time and material) or be used to correctively rework the flaw.
 
The proposed laser ultrasound technique can be used to detected both surface and subsurface defects, and can be used to inspect the material microstructure or texture. Working on as-deposited SLM material is challenging due to the high surface roughness. We will present results of the laser ultrasonic technique – spatially resolved acoustic spectroscopy (SRAS) – on as deposited material from a build chamber compatible instrument. We will discuss the possibilities for defect and microstructure control, and the challenges remaining for online inspection.},
 
  type = {Oral},
 
  institution = {45th {{Annual Review}} of {{Progress}} in {{Quantitative Nondestructive Evaluation}} ({{45QNDE}})},
 
  date = {2018-07-16},
 
  author = {{Rikesh Patel}, {Paul Dryburgh, Don Pieris, Wenqi Li, Richard Smith, Matt Clark, Adam Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{paul_dryburgh_spatially_2018-1,
 
  venue = {{Austin TX (USA)}},
 
  title = {Spatially {{Resolved Acoustic Spectroscopy}} ({{SRAS}}) for Additive Manufacturing},
 
  url = {http://sffsymposium.engr.utexas.edu/},
 
  abstract = {High-integrity engineering applications will not permit the incorporation of many defects observed in current the class of powder-bed fabrication systems. As such, there are limitations to the engineering context that this manufacturing method may be used in. Microstructure and defect interrogation are key aspects for pushing additive manufacturing forward, assuring part quality. In addition, online measurements allow for closed-loop feedback, where component measurements can inform remedial action, or vary processing parameters during fabrication.
 
The acoustic microscopy technique spatially resolved acoustic spectroscopy is an exciting proposition for use in component integrity assessment, due to its ability to detect surface and subsurface defects, and probe material properties. This talk will introduce typical datasets from both prepared and as-deposited AM surfaces, and discuss the opportunity presented by collecting data online, focusing on rework of defects. The talk will conclude with an overview of progress made towards online integration and on-going challenges.},
 
  type = {Oral},
 
  institution = {29th {{Annual International Solid Freeform Fabrication Symposium}} ({{SFF2018}})},
 
  date = {2018-08-14},
 
  author = {{Paul Dryburgh}, {Don Milesh Pieris, Rikesh Patel, Richard J Smith, Steve Sharples, Matt Clark, Adam T Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{paul_dryburgh_use_2018,
 
  venue = {{Furth (Germany)}},
 
  title = {The Use of a Laser to Monitor and Correct in {{SLM}}},
 
  url = {https://www.lane-conference.org/},
 
  type = {Oral},
 
  institution = {10th {{CIRP Conference}} on {{Photonic Technologies}} ({{LANE2018}})},
 
  year = {04/Sept/2018},
 
  author = {{Paul Dryburgh}, {Don Milesh Pieris, Rikesh Patel, Matthias Hirsch, Richard J Smith, Steve Sharples, Matt Clark, Adam T Clare}},
 
  editoratype = {collaborator}
 
}
 
 
</bibtex> <bibtex>@techreport{don_pieris_spatially_2018,
 
  venue = {{Nottingham (UK)}},
 
  title = {Spatially Resolved Acoustic Spectroscopy Additive Manufacturing – towards Online Inspection},
 
  url = {http://www.bindt.org/events/PastEvents/ndt-2018/},
 
  abstract = {High-integrity engineering applications such as aerospace will not permit the incorporation of components containing any structural defects. The current generation of additive manufacturing platforms yield components with relatively high levels of defects. The in-line inspection of the components built using additive can provide closed-loop feedback and vary build parameters during fabrication to minimise such defects. This article reviews the capability of spatially resolved acoustic spectroscopy to be used as an in-line inspection tool for detecting the changes in parts induced due to variations in build parameters. The first considers the build laser power and the second varies the laser scan strategy used to build the component. Using the detected probe light intensity map and the measured surface acoustic velocity, the detection of surface defects, subsurface defects and component microstructure can be measured.},
 
  type = {Oral},
 
  institution = {{{BINDT}}},
 
  year = {10/Sept/2018},
 
  author = {{Don Pieris}, {Rikesh Patel, Paul Dryburgh, Matthias Hirsch, Wenqi Li, Steve D. Sharples, Richard J. Smith, Adam T. Clare, Matt Clark}},
 
  editoratype = {collaborator},
 
  note = {Winner student prize}
 
}
 
 
</bibtex> <bibtex>@techreport{wenqi_li_spatially_2018,
 
  venue = {{Erice (Italy)}},
 
  title = {Spatially Resolved Acoustic Spectroscopy ({{SRAS}}): A {{NDE}} Technique for Materials Characterisation Based on Laser Ultrasonic},
 
  url = {http://www.sbai.uniroma1.it/conferenze/photoacoustic-photothermal/},
 
  type = {Oral},
 
  institution = {Progress in {{Photoacoustic}} \& {{Photothermal Phenomena Focus}} on {{Biomedical}}, {{Nanoscale}}, {{NDE}} and {{Thermophysical Phenomena}} and {{Technologies}} ({{PAPT2018}})},
 
  year = {11/Sept/2018},
 
  author = {{Wenqi Li}, {Rikesh Patel, Paul Dryburgh, Don Milesh Pieris, Richard Smith, Adam Clare, Matt Clark}},
 
  editoratype = {collaborator},
 
  note = {Winner best paper}
 
}
 
 
</bibtex>
 
</bibtex>

Latest revision as of 09:31, 31 August 2021

Rikesh Patel

Rp portrait.jpg

Assistant Professor, Department of Electrical and Electronic Engineering, University of Nottingham

Address: A46 Coates Building, University Park, Nottingham, NG7 2RD, UK

Phone: +44 (0)115 84-67892

Email: rikesh.patelAtnotts.png

ORCID: 0000-0003-0751-4533

External links:

UoN repository (old link)

Google Scholar

ResearchGate

Grants on the web

Journal publications

Lee, Yong, Kitazawa, So, Patel, Rikesh - Simple Method of Measuring Thicknesses of Surface-Hardened Layers by Laser Ultrasonic Technique
Jpn. J. Appl. Phys. ,2021
https://iopscience.iop.org/article/10.35848/1347-4065/ac030f
Bibtex
Author : Lee, Yong, Kitazawa, So, Patel, Rikesh
Title : Simple Method of Measuring Thicknesses of Surface-Hardened Layers by Laser Ultrasonic Technique
In : Jpn. J. Appl. Phys. -
Address :
Date : 2021

Patel, Rikesh, Sharples, Steve D., Clark, Matt, Somekh, Mike G., Li, Wenqi - Single Pixel Camera Methodologies for Spatially Resolved Acoustic Spectroscopy
Appl. Phys. Lett. 118(5):051102,2021
https://aip.scitation.org/doi/10.1063/5.0040123
Bibtex
Author : Patel, Rikesh, Sharples, Steve D., Clark, Matt, Somekh, Mike G., Li, Wenqi
Title : Single Pixel Camera Methodologies for Spatially Resolved Acoustic Spectroscopy
In : Appl. Phys. Lett. -
Address :
Date : 2021

Brown, M., Pieris, D., Wright, D., Crawforth, P., M'Saoubi, R., McGourlay, J., Mantle, A., Patel, R., Smith, R.J., Ghadbeigi, H. - Non-Destructive Detection of Machining-Induced White Layers through Grain Size and Crystallographic Texture-Sensitive Methods
Materials \& Design 200:109472,2021
https://linkinghub.elsevier.com/retrieve/pii/S0264127521000253
Bibtex
Author : Brown, M., Pieris, D., Wright, D., Crawforth, P., M'Saoubi, R., McGourlay, J., Mantle, A., Patel, R., Smith, R.J., Ghadbeigi, H.
Title : Non-Destructive Detection of Machining-Induced White Layers through Grain Size and Crystallographic Texture-Sensitive Methods
In : Materials \& Design -
Address :
Date : 2021

Dryburgh, Paul, Pieris, Don, Martina, Filomeno, Patel, Rikesh, Sharples, Steve, Li, Wenqi, Clare, Adam T., Williams, Stewart, Smith, Richard J. - Spatially Resolved Acoustic Spectroscopy for Integrity Assessment in Wire-Arc Additive Manufacturing
Additive Manufacturing 28:236--251,2019
https://linkinghub.elsevier.com/retrieve/pii/S2214860419302994
Bibtex
Author : Dryburgh, Paul, Pieris, Don, Martina, Filomeno, Patel, Rikesh, Sharples, Steve, Li, Wenqi, Clare, Adam T., Williams, Stewart, Smith, Richard J.
Title : Spatially Resolved Acoustic Spectroscopy for Integrity Assessment in Wire-Arc Additive Manufacturing
In : Additive Manufacturing -
Address :
Date : 2019

Pieris, D, Patel, R, Dryburgh, P, Hirsch, M, Li, W, Sharples, S D, Smith, R J, Clare, A T, Clark, M - Spatially Resolved Acoustic Spectroscopy Towards Online Inspection of Additive Manufacturing
Insight - Non-Destructive Testing and Condition Monitoring 61(3):132--137,2019
https://www.ingentaconnect.com/content/10.1784/insi.2019.61.3.132
Bibtex
Author : Pieris, D, Patel, R, Dryburgh, P, Hirsch, M, Li, W, Sharples, S D, Smith, R J, Clare, A T, Clark, M
Title : Spatially Resolved Acoustic Spectroscopy Towards Online Inspection of Additive Manufacturing
In : Insight - Non-Destructive Testing and Condition Monitoring -
Address :
Date : 2019

Patel Rikesh, Hirsch Matthias, Dryburgh Paul, Pieris Don, Achamfuo-Yeboah Samuel, Smith Richard, Light Roger, Sharples Steve, Clare Adam, Clark Matt - Imaging Material Texture of As-Deposited Selective Laser Melted Parts Using Spatially Resolved Acoustic Spectroscopy
8(10):1991
http://www.mdpi.com/2076-3417/8/10/1991
Bibtex
Author : Patel Rikesh, Hirsch Matthias, Dryburgh Paul, Pieris Don, Achamfuo-Yeboah Samuel, Smith Richard, Light Roger, Sharples Steve, Clare Adam, Clark Matt
Title : Imaging Material Texture of As-Deposited Selective Laser Melted Parts Using Spatially Resolved Acoustic Spectroscopy
In : -
Address :
Date :

Speidel Alistair, Su Rong, Mitchell-Smith Jonathon, Dryburgh Paul, Bisterov Ivan, Pieris Don, Li Wenqi, Patel Rikesh, Clark Matt, Clare Adam T. - Crystallographic Texture Can Be Rapidly Determined by Electrochemical Surface Analytics
159:89-101
https://linkinghub.elsevier.com/retrieve/pii/S1359645418305998
Bibtex
Author : Speidel Alistair, Su Rong, Mitchell-Smith Jonathon, Dryburgh Paul, Bisterov Ivan, Pieris Don, Li Wenqi, Patel Rikesh, Clark Matt, Clare Adam T.
Title : Crystallographic Texture Can Be Rapidly Determined by Electrochemical Surface Analytics
In : -
Address :
Date :

Colombi, Andrea, Ageeva, Victoria, Smith, Richard J., Clare, Adam, Patel, Rikesh, Clark, Matt, Colquitt, Daniel, Roux, Philippe, Guenneau, Sebastien, Craster, Richard V. - Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces
Scientific Reports 7(1), Dec 2017
http://www.nature.com/articles/s41598-017-07151-6
Bibtex
Author : Colombi, Andrea, Ageeva, Victoria, Smith, Richard J., Clare, Adam, Patel, Rikesh, Clark, Matt, Colquitt, Daniel, Roux, Philippe, Guenneau, Sebastien, Craster, Richard V.
Title : Enhanced sensing and conversion of ultrasonic Rayleigh waves by elastic metasurfaces
In : Scientific Reports -
Address :
Date : Dec 2017

M. Hirsch, P. Dryburgh, S. Catchpole-Smith, R. Patel, L. Parry, S.D. Sharples, I.A. Ashcroft, A.T. Clare - Targeted rework strategies for powder bed additive manufacture
Additive Manufacturing 19:127 - 133,2018
https://www.sciencedirect.com/science/article/pii/S2214860417303925
Bibtex
Author : M. Hirsch, P. Dryburgh, S. Catchpole-Smith, R. Patel, L. Parry, S.D. Sharples, I.A. Ashcroft, A.T. Clare
Title : Targeted rework strategies for powder bed additive manufacture
In : Additive Manufacturing -
Address :
Date : 2018

Rikesh Patel, Wenqi Li, Richard J. Smith, Steve D. Sharples, Matt Clark - Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy
Scripta Materialia 140(Supplement C):67 - 70,2017
http://www.sciencedirect.com/science/article/pii/S1359646217303846
Bibtex
Author : Rikesh Patel, Wenqi Li, Richard J. Smith, Steve D. Sharples, Matt Clark
Title : Orientation imaging of macro-sized polysilicon grains on wafers using spatially resolved acoustic spectroscopy
In : Scripta Materialia -
Address :
Date : 2017

Hirsch, M., Catchpole-Smith, S., Patel, R., Marrow, P., Li, Wenqi, Tuck, C., Sharples, S. D., Clare, A. T. - Meso-scale defect evaluation of selective laser melting using spatially resolved acoustic spectroscopy
Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences 473(2205),2017
http://rspa.royalsocietypublishing.org/content/473/2205/20170194
Bibtex
Author : Hirsch, M., Catchpole-Smith, S., Patel, R., Marrow, P., Li, Wenqi, Tuck, C., Sharples, S. D., Clare, A. T.
Title : Meso-scale defect evaluation of selective laser melting using spatially resolved acoustic spectroscopy
In : Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences -
Address :
Date : 2017

Matthias Hirsch, Rikesh Patel, Wenqi Li, Guangying Guan, Richard K. Leach, Steve D. Sharples, Adam T. Clare - Assessing the capability of in-situ nondestructive analysis during layer based additive manufacture
Additive Manufacturing 13:135 - 142,2017
http://www.sciencedirect.com/science/article/pii/S2214860416301877
Bibtex
Author : Matthias Hirsch, Rikesh Patel, Wenqi Li, Guangying Guan, Richard K. Leach, Steve D. Sharples, Adam T. Clare
Title : Assessing the capability of in-situ nondestructive analysis during layer based additive manufacture
In : Additive Manufacturing -
Address :
Date : 2017

Richard J. Smith, Matthias Hirsch, Rikesh Patel, Wenqi Li, Adam T. Clare, Steve D. Sharples - Spatially resolved acoustic spectroscopy for selective laser melting
Journal of Materials Processing Technology 236:93 - 102,2016
http://www.sciencedirect.com/science/article/pii/S0924013616301352
Bibtex
Author : Richard J. Smith, Matthias Hirsch, Rikesh Patel, Wenqi Li, Adam T. Clare, Steve D. Sharples
Title : Spatially resolved acoustic spectroscopy for selective laser melting
In : Journal of Materials Processing Technology -
Address :
Date : 2016

Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark - Widefield two laser interferometry
Opt. Express 22(22):27094--27101, Nov 2014
http://www.opticsexpress.org/abstract.cfm?URI=oe-22-22-27094
Bibtex
Author : Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark
Title : Widefield two laser interferometry
In : Opt. Express -
Address :
Date : Nov 2014

Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark - Ultrastable heterodyne interferometer system using a CMOS modulated light camera
Opt. Express 20(16):17722--17733, Jul 2012
http://www.opticsexpress.org/abstract.cfm?URI=oe-20-16-17722
Bibtex
Author : Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark
Title : Ultrastable heterodyne interferometer system using a CMOS modulated light camera
In : Opt. Express -
Address :
Date : Jul 2012

Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark - Widefield heterodyne interferometry using a custom CMOS modulated light camera
Opt. Express 19(24):24546--24556, Nov 2011
http://www.opticsexpress.org/abstract.cfm?URI=oe-19-24-24546
Bibtex
Author : Rikesh Patel, Samuel Achamfuo-Yeboah, Roger Light, Matt Clark
Title : Widefield heterodyne interferometry using a custom CMOS modulated light camera
In : Opt. Express -
Address :
Date : Nov 2011