Effect of In-situ TiC on Microstructure and Properties of AlCoCrFeNiMo High Entropy Alloy Laser Cladding Layer
Chenxiao Song, Jinpeng Bi, Wei Zhao, Jia Yanjun, Hui Zhang and Yuexia Lv
The AlCoCrFeNiMo(TiC)x (x = 0, 0.25, 0.5, 0.75, 1, 1.25 and 1.5) high entropy alloy cladding layer was prepared in this study using a laser cladding technology. The microstructure, wear resistance, high-temperature oxidation resistance, and corrosion resistance of the cladding layer were further comprehensively investigated by scanning electron microscopy, reciprocating friction and wear tester, muffle furnace experiments, and electrochemical tests. The research results demonstrate that, the microstructure of TiC particles transitioned from spherical to dendritic with the increase of x, accompanied by increasing proportion of in-situ TiC phase and decreasing proportion of Mo-rich regions. The properties of the cladding layer was changed due to the evolution of microstructure. The microhardness, wear resistance, high-temperature oxidation resistance and corrosion resistance of the cladding layer first increased and then decreased with the increase of x. Specifically, the highest average microhardness and corrosion resistance of the cladding layer can be achieved at x=0.25 and x=0.5, respectively. The optimal wear resistance and high-temperature oxidation resistance of the cladding layer are both obtained at x=0.75.
Keywords: laser cladding, in-situ TiC, microstructure evolution, high entropy alloy