NDE for AM

NDE for AM

Our optics group is currently working on a number of ways to perform non-destructive evaluation on additive manufactured parts. This is an important field of research as 3D printed parts becomes much faster and cheaper, as well as more practically viable as the primary manufacturing method. However, currently the main draw back with 3D printing is reliability - on the outside things could look as they should, but on the inside, there may be pores, cracks or design flaws that may have been missed in initial surface testing. This is especially critical for performance parts (aerospace, medical, automotive, construction, etc).

SRAS on SLM parts

The motivation for this projects is to incorporate our existing laser ultrasonic technology in to measuring AM parts as they print. SRAS has been used in the past to image the micro-structure (grains) of metal parts - this gives an indication of the parts physical properties. In addition to this useful information, the loss of signal or a drastic change in signal amplitude/frequency can indicate a change in the surface (e.g. pore, delamination) and, perhaps more critically, the subsurface region around the area being

3D printers can use different materials to create structures using different methods - an SLM machine prints metal parts by creating layers of laser fused metal powder. By incorporating the SRAS instrument into the SLM printer, it is possible to create 3D renders, layer by layer, of what was actually printed (inc. defects).

The challenges in this project are both in the optical setup, such as measuring signals off rough surfaces, as well as mechanical integration, where atmosphere, temperature, interfering particles are all factors to overcome.