Just came across this great content! GREAT job on the content and moderation. Here is my opinion on why the failure... In addition to what was discussed, I believe we need to consider the thermal history of the specimen. It appears that early failure in bed adhesions was the start of this failure. The bed adhesion can be due to two issues: 1. Contamination: from stock material and/or build plate surface 2. Stresses due to thermal expansion rates in the specimen and build plate. After the local failure of the specimen, the heat dissipation through the build plate is reduced. Therfore, consecucutive print layers, at mentione location, remain at higher temperatures, which can lead to warpage of the part (therefore uneven top height of the part). Altogether, the bubbling effect seems to be as the result of multiple layers of the melt pool (molten power by laser) cooling on a previous uneven layer, where hindered thermal performance causes multiple layers to be diffused together.
I'm very excited for this series! This is a large part of my Master's research. Understanding how all these dozens of variables affect the part and being able to predict/prevent them will open up AM for wider use in aerospace.
Just came across this great content! GREAT job on the content and moderation.
Here is my opinion on why the failure...
In addition to what was discussed, I believe we need to consider the thermal history of the specimen. It appears that early failure in bed adhesions was the start of this failure.
The bed adhesion can be due to two issues:
1. Contamination: from stock material and/or build plate surface
2. Stresses due to thermal expansion rates in the specimen and build plate.
After the local failure of the specimen, the heat dissipation through the build plate is reduced. Therfore, consecucutive print layers, at mentione location, remain at higher temperatures, which can lead to warpage of the part (therefore uneven top height of the part). Altogether, the bubbling effect seems to be as the result of multiple layers of the melt pool (molten power by laser) cooling on a previous uneven layer, where hindered thermal performance causes multiple layers to be diffused together.
I'm very excited for this series! This is a large part of my Master's research. Understanding how all these dozens of variables affect the part and being able to predict/prevent them will open up AM for wider use in aerospace.
Great episode, thanks for all the wonderful content and information.
We need this every week