Additive manufacturing powder bed part failure

Photograph reference of a powder bed build that "tore itself in half" along layer lines. Tom's parallel anecdote: Joule Printing 15 months prior could not make a 6"×6" part without cracking; speeding up the machine resolved the diffusion/porosity problem.

Alex: Let's talk a little bit about the thermal management component. This is a huge thing in metal additive — I guess in any manufacturing, but especially in 3D printing. When you melt metal, it expands; when you cool it, it contracts. When you have one section of your part that's very hot and one section that's very cold, you start to deal with a lot of internal stresses. Parts manufactured with a lot of additive manufacturing processes will literally tear themselves in half, especially along layer lines where there may not be great fusion and strength. This is an example that's not atypical in 3D printing — a powder bed build that will tear itself apart. So this is a large factor when you're thinking about how to design parts for the process, how to orient parts within a build, how to support them, how to optimize parameters. Different metal manufacturing processes have different heat loads and residual stresses.