Abstract
In the present study, AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA) was fabricated by laser melting deposition (LMD). Then, post-heat treatment was performed at different temperatures to investigate its effects on microstructure and corrosion property of the alloy. The results obtained from microstructural characterization indicate that the alloy, whether heat-treated or not, exhibited a lamellar eutectic microstructure composed of alternating FCC and BCC phases. With the increase in the heating temperature from 600 to 1000 °C, the interlamellar spacing and volume fraction of the FCC phase gradually increased. Electrochemical testing in 3.5 wt.% NaCl solution revealed that the resistance of the alloy to corrosion was improved with the increasing heating temperature, which was attributed to the increased volume fraction of the FCC phase. However, the immersion test in 3.5 wt.% NaCl solution also suggests that heating above 800 °C increased the susceptibility of the alloy to pitting corrosion, due to the more pronounced enrichment of Al in the BCC phase.