Effects of process parameters on interfacial characterization and mechanical properties of 316L/CuCrZr functionally graded material by selective laser melting

Abstract

Steel-Copper functionally graded material (FGM) has shown potential in extreme environments. Selective laser melting (SLM), one of the additive manufacturing technologies, is applied to form FGM with incompatibility between two or more alloys. In this work, the effects of process parameters on the interfacial characterization of 316L/CuCrZr FGM fabricated by SLM are addressed. A processing map for CuCrZr tracks on SLM processed 316L substrate is developed by the classification of surface morphologies. Furthermore, the interfacial characteristics, microscopic features, tensile properties and microhardness of 316L/CuCrZr FGM are investigated. Experimental results illustrate that the process parameters of regular scanned tracks in a range of linear energy density (LED) from 0.535 to 1.0625 J/mm are suitable for the formation of 316L/CuCrZr FGM. It is observed that the increase in laser power and scanning space and the decrease in scanning speed restrain the generation of cracks in the 316L region. Additionally, the ultimate tensile strengths of the vertically and horizontally integrated 316L/CuCrZr FGM are 318.2 ±7.2 MPa and 519.8 ±6.2 MPa, respectively. The microhardness decreases from 234.5 ±3.9 HV in 316L region to 130.25 ±5.65 HV in CuCrZr region. This provides valuable guidance for the fabrication of Steel-Copper FGM by SLM.