Effects of Build Orientation and Hatch Spacing on High-Speed Milling Behavior of L-PBF 316L Stainless Steel

Abstract

Due to the philosophy of the process, the surface roughness is usually high for the parts produced with laser powder bed fusion (L-PBF) additive manufacturing (AM). Parts produced by this method need surface quality improvement processes for many applications. One of the methods used for this purpose is high speed machining (HSM). HSM is a modern manufacturing technique that offers several benefits, including improved productivity, enhanced product quality, and reduced production costs. In addition, HSM can improve the quality of finished products by reducing machining errors. In this study, samples produced with 316L powder in size of 10 x 10 x 5 mm using three different hatch spacings (60, 70, 80 mu m) and building orientations (0 degrees, 45 degrees, 90 degrees) were produced by L-PBF method, and HSM process was applied to these samples. In this context, the present study aimed to investigate the effects of porosity, microstructure and microhardness properties of 316L samples produced by L-PBF method using different hatch spacings and build orientations on cutting forces, surface roughness and burr formation in HSM. When the numerical values of the cutting forces were analyzed in both x and y directions, it was observed that the greatest cutting force occurred in the x direction. While the Fx force ranged from 6.23 to 9.35 N, the Fy force ranged from 4.88 to 8.27 N. It has been determined that as the build orientation increases at the same hatch spacing value, the cutting forces increase due to the increased porosity ratio.