Chip formation in stainless steel from additive manufacturing

In recent years, materials have evolved across all fields. The goal is to develop materials that are increasingly resistant while also being lightweight, stainless, and tough. All these mechanical and physical properties require increasingly complex microstructures, which can directly affect the cutting process. Adding additive manufacturing to this equation—with its ability to produce even more complex structures—makes mastering the cutting process difficult and its prediction nearly impossible. The objective of this paper is to investigate, in the case of an additively manufactured stainless steel (316L) produced using different manufacturing routes, the relationships between microstructure and the cutting process. The analyses are based on the observation of the cutting process through post-mortem examinations of chips, chemical analyses of material evolution, as well as microstructural characterizations such as EBSD tests. In addition, a specific setup was developed to ensure that each test applies a mechanically oriented load with respect to the build plane. Finally, the cutting process partly relies on the creation of a crack initiated by the tool. This crack then becomes the beginning of the shear within the primary shear zone. One possible indicator of machinability is toughness. Part of this study therefore explores the impact of toughness modification on the cutting process.