Selective Laser Melting and Subtractive Hybrid Manufacture AISI420 Stainless Steel: Evolution on Surface Roughness and Residual Stress

Abstract

Selective laser melting has the ability to produce extremely complex components, providing technical support for materials and structures integrated manufacturing of high performance components. Stability of molten pool, interfacial bonding property of molten pool and wettability of melt and substrate have an influence on microstructure, surface precision and roughness of components during the interaction of laser and material. Thus, high surface roughness of SLMed parts limits its development. Selective laser melting and subtractive hybrid manufacture is one of the development trends. Therefore, the milling method is taken to improvement surface quality of SLM-processed samples. Influence of surface roughness and residual stress by different porosity, different milling depth and different milling surface is studied. Surface roughness has been greatly improved and decreased from 10 μm to 1 μm after milling. The horizontal direction residual stress of the sample has changed from compressive stress to tensile stress and reduced a lot by milling.