Abstract: To improve the wear resistance of the kneading blade in the forage grass kneading and cutting machine, Ni60a/SiC composite powder cladding layer is prepared on 65Mn steel surface by laser cladding technology. The microhardness, phase composition, friction and wear properties of the coating are analyzed to obtain the best combination of laser cladding process parameters. The results show that the primary and secondary process parameters affect the hardness of clad layer are spot diameter, laser power, and scanning speed. The cladding layer has precipitation of new phase which mainly consists of hard phases such as NiCrO₃ and Cr₃Ni₂SiC. The optimum combination of laser cladding parameters is laser power 2 000 W, scanning speed 400 mm/min and spot diameter 3 mm. Under this parameter, the micro-hardness of the cladding layer is 870 HV_0.1, which also exhibits efficient metallurgical bonding with the substrate. In the same wear test conditions, the wear form of the cladding layer is mainly abrasive wear and the amount of wear is 0.003 g. Compared with the wear parameters of the 65Mn based, the friction coefficient is reduced by 29%, the depth of wear scar depth is reduced by 83%, and the wear resistance of the composite coating increases significantly, This study has a good reference value in improving the service life of the blade.

Key words: blade, laser cladding, cladding parameters, wear resistance