LAUSR

Herein, the Co‐free, low‐cost dual‐phase AlCrCuFeNi3 high‐entropy alloy (HEA) is successfully developed by in situ alloying induced by selective laser melting (SLM) technique from an initial mixture of Ni and AlCrCuFeNi alloy powders. The effect of process parameters on the microstructure and strength of the SLMed AlCrCuFeNi3 HEA is investigated. It is found that the degree of in situ alloying strongly depends on the laser power. Low laser power leads to insufficient in situ alloying, and a large amount of incompletely diffused Ni and body‐centered cubic (BCC) AlCrCuFeNi alloy powder blocks remain, forming the eutectic structure with alternating face‐centered cubic and BCC phases. With the increase in laser power, the degree of in situ alloying increases, resulting in a decrease in the number of BCC phases as well as the yield strength of the SLMed AlCrCuFeNi3 HEA. The highest yield strength of the SLMed AlCrCuFeNi3 HEA is obtained at low laser power (200 W–600 mm s−1), reaching 689.02 ± 17.54 MPa.