Improving surface and porosity analyses of laser powder bed fusion parts through CT-based three-dimensional metal powder characterization

X-ray computed tomography (CT) can be used to perform three-dimensional (3D) measurements of both size and shape of metal powder used as feedstock material in laser powder bed fusion (LPBF). Such powder characteristics – which can be altered when employing particles recovered after being used although not processed in previous processes – are known to have a significant influence on typical LPBF process issues and product flaws, such as the presence of internal defects and complex surface texture. This work investigates the possibility to exploit the CT-based 3D powder characterization to guide and improve the evaluation of surface texture and internal pores by aiding the identification of surface features due to unstable process conditions and the discrimination between pores caused by insufficient fusion and voids caused by the presence of spatter formation.