The influence of material anisotropy on the machinability of laser additive manufactured stainless steel 316L

Abstract

In the laser directed energy deposition (DED) additive manufacturing process, changes in scanning strategies can lead to differences in the material's microstructure, resulting in variations in material properties, which in turn affect the material's machining performance. The differences in microstructure are mainly reflected in the anisotropy and micro defects of materials. To investigate their impact on cutting performance, this study utilized laser DED technology to fabricate 316 L stainless steel samples using two scanning strategies (0° and 90°). A comparative milling study was conducted on the DED-manufactured samples and cast samples. From a microstructural perspective (including the Schmid factor and dislocation density), the study analyzed the effects on cutting forces and examined how changes in dislocation density influence the formation of serrated chips. Using the wear delamination theory, the influence of micro-defects on tool wear under adiabatic heating conditions was explored. Additionally, the adhesive wear and diffusion wear on the cutting tools after machining were analyzed. Experimental results showed that cutting the DED 0° samples resulted in higher cutting forces and more severe tool wear. This study provides theoretical guidance for improving the machinability of materials by optimizing the DED manufacturing process.