Microstructure and Wear Resistance of Alcocrfeni-Wc/Tic Composite Coating by Laser Cladding

Abstract

AlCoCrFeNi has excellent mechanical properties, however, its hardness and wear resistance are insufficient for engineering applications. In this work, the WC and in-situ TiC particles were used to enhance the wear resistance of AlCoCrFeNi coating. The microstructure, hardness, and wear resistance were studied in detail. The results showed that the in-situ TiC particles were uniformly distributed in the whole coating, ameliorating the uneven distribution of WC particles. A sound interface was formed between the particles and the coating matrix, proving the composite coating performed well in wear resistance. The phase constituents of the coating matrix were the BCC and B2 phases. The dissolution of W atoms led to an increase in the lattice constants of the BCC phase, resulting in strong solid solution strengthening of the coating matrix. Furthermore, a needle W-rich BCC phase appeared in the coating matrix with the increase of WC content. As a result, the hardness of AlCoCrFeNi-WC/TiC coatings increased from 516.4 HV0.3 to 808.7 HV0.3, and the wear resistance was increased by 14 times. Therefore, the improvement in hardness can be attributed to the WC particles, in-situ TiC particles, and solid-solution strengthening.

Keywords: High entropy alloy, laser cladding, Microstructure, WC particles, Wear resistance