Early binder jetting porosity defect

Physical sample displayed by Tom (borrowed from Mike Tarkanian). Demonstrates the 50% void / 50% shrinkage problem of powder-bed processes and the resulting defects visible on the fracture surface.

[Tom holds up samples from Desktop Metals.] If you go down the hall here — I stole these from Mike Tarkanian, sent him an email that I'd stolen them — these are demos from Desktop Metals, which is a startup literally a quarter mile down the road from Digital Alloys. They use a powder bed process. The problem with powder bed process is, it's 50 percent void, so it shrinks by 50 percent when you densify it. That leaves behind defects, so if you look on that broken piece you'll see the defects.