Powders for Additive Manufacturing Process: Characterization Techniques and Effects on Part Properties

Powder-bed based Additive Manufacturing is a class of Additive Manufacturing (AM) processes that bond successive layers of powder by laser melting to facilitate the creation of parts with complex geometries. As AM technology transitions from the fabrication of prototypes to end-use parts, the understanding of the powder properties needed to reliably produce parts of acceptable quality becomes critical. Consequently, this has led to the use of powder characterization techniques such as scanning electron microscopy (SEM), laser light diffraction, x-ray photoelectron spectroscopy (XPS), and differential thermal analysis (DTA) to both qualitatively and quantitatively study the effect of powder characteristics on part properties. Utilization of these powder characterization methods to study particle size and morphology, chemical composition, and microstructure of powder has resulted in significant strides being made towards the optimization of powder properties for powder-bed based AM processes. This paper reviews methods commonly used in characterizing metallic AM powders, and the effects of powder characteristics on the part properties in these AM processes.