Effect of Rare Earth on Microstructure and Wear Resistance of In-Situ-Synthesized Mo2FeB2 Ceramics-Reinforced Fe-Based Cladding.

Mo2FeB2 ceramics-reinforced Fe-based cladding with various rare earth (RE) concentrations were prepared by the carbon arc surfacing process. The effects of RE content on the microstructure, phase composition, hardness and wear resistance of the cladding were systematically discussed. Meanwhile, the area fraction and grain size of Mo2FeB2 phase were exactly measured. Moreover, the refining mechanism of rare earth Y was analyzed. Results revealed that the claddings consisted of Mo2FeB2, FeCr, MoB and CrB. Adding the rare-earth Y decreased the grain sizes of Mo2FeB2 phase. Furthermore, grain-refining effects of Mo2FeB2 phase were significant when the RE content was 2% and hard phases evenly distributed in the cladding. In addition, the maximum microhardness value of claddings was about 1078 HV. The claddings with 2% RE contents had better wear resistance, which was equivalent to a sintered sample.