The Microstructure and Properties of Ni60 cladding layer by Laser Cladding on TC4 Alloy Surface

Abstract

Laser cladding was used to prepare a Ni60 cladding layer on the surface of TC4 alloy to enhance its hardness and wear resistance. Single-factor experiments were conducted to compare the effects of laser power, powder feeding speed, and scanning speed on the morphology, dilution rate, and microhardness of the Ni60 cladding layer. Based on fewer cracks, high hardness, and moderate dilution rate, the optimum parameters were determined. According to the results, when the laser power was 1000 W, powder feeding rate was 1.8 r/min, and scanning speed was 6 mm/s, the Ni60 cladding layer was crack-free, bonded to the TC4 substrate by metallurgical means, with a columnar and equiaxed crystalline microstructure, consisting of γ-Ni, Cr3C2, TiC, TiNi, Cr3Ni12 phases, etc. Compared to the TC4 substrate, the Ni60 cladding layer is about 2.30 times harder with an average microhardness of 836.71 HV1. Ni60 cladding layer and TC4 substrate had friction coefficients of 0.39 and 0.63, the weight loss was 21 mg and 115 mg, and the wear mechanisms were abrasive wear and adhesive wear, respectively. According to the results, the Ni60 cladding layer effectively enhances the TC4 substrate’s microhardness and wear resistance.