The microstructure, mechanical compression, and electrochemical behavior of novel equiatomic CoCrMoNiW and Co-rich Co50Cr12.5Mo12.5Ni12.5W12.5 high-entropy alloys fabricated by vacuum arc remelting

Abstract

In this research, we developed and analyzed novel equiatomic CoCrMoNiW and Co-rich Co50Cr12.5Mo12.5Ni12.5W12.5 high-entropy alloys (HEAs). Using FactSage, we identified dual face-centered cubic (FCC) and body-centered cubic (BCC) phases in the equiatomic HEA and a predominant FCC phase in the Co-rich HEA. The results of an elemental analysis reveal the significant presence of W and Mo in the equiatomic HEA and Co, Cr, and Ni in the Co-rich HEA. X-ray diffraction revealed dual-phase FCC and BCC structures in both HEAs, with the presence of an intermetallic μ phase. The Co-rich HEA exhibited significant compressive strain due to the prevalence of the ductile FCC phase at the expense of corrosion resistance. On the other hand, the CoCrMoNiW HEA demonstrated superior corrosion resistance comparable to those of the L605 alloy and 316 L stainless steel.