Microstructure and wear resistance of CoCrNbNiW high-entropy alloy coating prepared by laser melting deposition

Abstract

The defect-free CoCrNbNiW high-entropy alloy coating was successfully prepared by laser melting deposition, and its microstructure and wear resistance were investigated. The results showed that the microstructure of CoCrNbNiW high-entropy alloy coating consisted of fcc phase rich in Nb and fcc phase including un-melted W particles and rich in Cr. Moreover, an amount of fcc phase was formed at the middle and top of coating, while the bcc phase rich in Cr was formed at the bottom. Meanwhile, the un-melted W particles were diffusely distributed in the coating. Therefore, the microhardness of CoCrNbNiW high-entropy alloy coating was improved and was 2.78 times as high as that of substrate. The wear loss and wear rate of coating were 0.26 and 0.23 times higher than those of substrate, respectively. The wear resistance of substrate was obviously improved due to the preparation of CoCrNbNiW high-entropy alloy coating.