Effect of Trace Additions of Ti on the Microstructure of AlCoCrFeNi-Based High Entropy Alloy

In this study, the effect of Ti addition up to 0.075 in the atomic ratio to AlCoCrFeNi-based high entropy alloy was investigated. AlCoCrFeNi alloy has been reported to undergo spinodal decomposition into Al-Ni-rich (B2) and Cr-Fe-rich (A2) regions during solidification. The addition of trace Ti resulted in a greater degree of chemical segregation and a morphological change of Al-Ni-rich precipitate-like phase during the spinodal decomposition. In addition, trace amounts of Ti tend to be segregated along the grain boundary in the AlCoCrFeNi alloy, thus significantly refines the grain size of the AlCoCrFeNi alloy.