Microstructure and Wear Performance of ex/in-situ TiC reinforced CoCrFeNiW0.4Si0.2 High-entropy Alloy Coatings by Laser Cladding

Abstract

The W and extra/in-situ TiC reinforced CoCrFeNi high-entropy alloy coating was prepared on a 45 steel substrate by laser cladding. The synergistic effect of W and ex/in-situ TiC on the microstructure and wear properties of the coating was studied. The results showed that the ex/in-situ TiC promoted the selection of the FCC phase with a preferred orientation to the (111) crystal plane, and the increasing of in-situ TiC and W+ex-situ TiC/in-situ TiC resulted in the transformation of the FCC phase to the BCC phase. The microstructure of W+in-situ TiC coating was more uniform and two heterogeneous nucleation points Cr3C2 and TiC appeared in the coatings during the solidification process. The wear width, depth, and volume were minimized. The wear rate (2.54×10-6mm3/(N·m)) was an order of magnitude lower than that of CoCrFeNi (4.97×10-5 mm3/(N·m)). The W+in-situ TiC coating shows the best wear resistance. There were a small amount of wear debris and shallow furrow-like grooves, and the wear mechanism was abrasive wear. The synergistic effect of W and in-situ TiC on wear resistance was significant.