Download: Impact of Powder Size, Size Distribution and Morphology on Additive Manufacturing
Martin J. Conlon, Kamran Azari
The morphology and consistency of metal powder feedstock has a profound impact on the quality, integrity and reliability of parts produced using additive manufacturing. Analysis and tests conducted using AlSi7Mg powder provided by various suppliers in both powder-bed and direct energy device printers have identified the influence and importance of powder characteristics such as particle size, size distribution, sphericity, oxide layer thickness, microstructure, fines, agglomerates and surface condition on the resultant additively manufactured part. This paper will discuss and describe research investigating how these powder characteristics impact powder properties such as flowability, packing density, moisture sorption, chemical stability, particle cohesiveness and particle size segregation in the powder-bed. Importantly, the impact of various powder characteristics on key mechanical properties in the final product—such as dimensional accuracy, hardness, surface roughness, tensile strength, yield strength and density—will be demonstrated, discussed and explained.