An effective statistical approach to determine the most contributing process parameters on the surface roughness quality of hastelloy X components made by laser powder-bed fusion

One of the main challenges in laser powder-bed fusion (LPBF) of metal powders is to determine the correlation between the key process parameters and physical properties of the produced components. Additionally, unlike conventional manufacturing processes, LPBF, as one of the many additive manufacturing processes, involves a large number of process parameters hindering the use of conventional factorial design approaches for optimization. In this paper, a modified Plackett-Burman method supported by an experimental analysis is proposed to identify the most significant parameters on the surface roughness quality of the LPBF-made Hastelloy X coupons using an EOS 290 machine. Among more than 100 process parameters, 23 parameters are chosen for this study including laser power and speed for core, skin and contour scans as well as layer thickness, geometry, orientation, location, etc. The surface roughness values (S_q) are measured using a confocal microscope (VK-X250, Keyence, Japan). Then, the roughness measurements are statistically analyzed in Minitab® to determine the most significant process parameters affecting the roughness of the LPBF printed samples. Results of the statistical approach show that the skin thickness, geometry, and layer thickness are the most significant parameters affecting the surface roughness of Hastelloy X components made by the LPBF process.