2, Honeywell, Tucson, Arizona, United States
Powder bed fusion systems such as direct metal laser sintering (DMLS) provide unprecedented abilities to manufacture complex 3-D parts and structures; however, the process produces unused metal powder that can undergo significant change in chemistry and morphology. The ability to recycle the used powder that is typically found within the build volume and in the overflow compartments requires a thorough chemical and structural analysis in order to determine the extent of reusability. In this context, characterization of virgin powder and used powder for nickel-based and stainless steel based alloys was performed in this work in a rigorous fashion to compare and contrast properties such as composition, particle size distribution and morphology. This information was then used in conjunction with other process parameters (e.g. dose factor, spreader velocity, layer thickness, and laser energy density) to determine conditions that can enable the ready integration of used powder along with virgin powder. Experimental analysis was supported by ANSYS based process modeling in the optimization process, providing a path forward for cost effective additive manufacturing methods.