Effect of scanning speed on microstructure and mechanical properties of selective laser melting AlCoCrFeNi2.1 eutectic high-entropy alloy

Abstract

The AlCoCrFeNi2.1 eutectic high-entropy alloy was prepared by selective laser melting technology, and the effect of scanning speed on its density, microstructure and mechanical properties was studied. The maximum relative density of SLM AlCoCrFeNi2.1 EHEA can reach 99.7 %. This alloy consists of FCC and BCC/B2 phases, and the transition from FCC to BCC/B2 phase occurs with the increase of scanning speed. The microstructure consists of equiaxed crystals, columnar crystals and eutectic layered structures, and a large number of nanoscale B2 phase particles are dispersed in the BCC phase. The maximum ultimate tensile strength of the SLM AlCoCrFeNi2.1 EHEA is 1380 MPa, the elongation is 10 %, and brittle fracture is the main factor.