Fine-tuning Alloy Microchemistry for Additive Manufacturing

Texas A&M University researchers have adjusted the process for creating defect-free metal additive manufactured parts. The researchers identified, through a combination of machine learning and single-track 3D printing experiments utilizing laser bed powder fusion process, promising alloy chemistries and process parameters required to print parts with uniform properties at the microscale.

Alloy powders used for metal AM can be quite diverse containing metals, such as nickel, aluminum, and magnesium, at different concentrations. During printing, these powders cool rapidly after being heated by a laser beam. Since the individual metals in the alloy powder have very different cooling properties and consequently solidify at different rates, this mismatch can create microsegregation.

This defect appears as tiny pockets containing a slightly different concentration of the metal ingredients than other regions of the printed part. These inconsistencies compromise the mechanical properties of the printed part.

The research is supported by the United States Army Research Office and the National Science Foundation.