Effect of In-Situ Laser Remelting on the Microstructure of SS316L Fabricated by Micro Selective Laser Melting

Due to the increasing attention on additive manufacturing of micro components, an in-house micro-selective laser melting (SLM) system using a fine laser spot size and a small layer thickness with an ability to handle fine powders has been developed recently. In this research work, in-situ laser remelting effects on the part density and microstructure of the SS316L parts fabricated using micro SLM have been studied. After every layer of micro SLM, laser remelting was performed using the same laser source. Remelting effects have been investigated at different process conditions with varying laser power and scanning speeds. The effects of remelting on the part porosity and microstructure of the micro SLM parts have been studied. Experimental results revealed that in-situ laser remelting significantly influences the part density and microstructure of the 316L micro SLM parts. The study highlights that in addition to the purpose of improving the surface finish, laser remelting can be used to tailor the microstructure and hence mechanical properties of the micro SLM parts.