Selective laser melting of silver submicron powder modified 316L stainless steel: Influence of silver addition on microstructures and performances

Abstract

In order to enhance electrical conductivity and corrosion resistance of 316L stainless steel for advanced applications, submicron silver powder was introduced into the 316L stainless steel matrix by the mean of selective laser melting. The effects of silver addition (5 wt%) on the resultant microstructures and associated physical performances of the SLMed Ag-modified composite were comprehensively investigated. Results revealed that silver addition led to the decrease of relative density and formation of finer sub-grains. Pure silver phase existed in the SLMed Ag-modified composite in the forms of micro-size silver aggregations (uniformly distributed among the 316L stainless steel matrix) and nano-size silver particles (interspersed along sub-grain boundaries). Improved electrical conductivity and corrosion resistance were obtained after the addition of silver. The influencing mechanism of modifying particles on microstructures and properties of SLM metallic composites, obtained in this work, could benefit the development of novel metallic composites towards new applications of multi-function.