Microwave Characterization of Metal Powder Composites for Powder Property Characterization in Additive Manufacturing (AM)

Common additive manufacturing (AM) methods use metal powder feedstock. The properties of the metal powder such as, particle size distribution (PSD), morphology, and presence of surface oxides or other contaminants, can adversely affect the quality of the final built part. Microwave material characterization techniques potentially offer effective ways by which to evaluate such metal properties. To assess sensitivity of microwave signals to the properties of metal powder used in AM, different types of metal powder were incorporated into resin composite samples, whose dielectric properties were then measured using the completely filled-waveguide technique at both X-band (8.2-12.4 GHz) and Ka-band (26.5-40 GHz). These measurements revealed that microwave signals are sensitive to changes in the metal powder properties. The findings open the door for future investigations by which optimized techniques can be devised to do the same in an in-line manner during the AM process.