Microstructure and Wear Resistance of TiC-Ni60 Cladding Layer on Cr12MoV Die Steel

To improve the wear-resistant performance of cold work die steel and prolong its service life， hard TiC particles were introduced as reinforcing phases.Laser cladding technology was employed to fabricate both Ni60 and TiC-reinforced Ni60 composite cladding layers on Cr12MoV cold work die steel.Subsequently， the microstructure and friction and wear properties of the cladding layer were comparatively studied by scanning electron microscope，ball-disc high-temperature friction and wear testing machine and ultra-depth-of-field microscope.Results showed TiC ceramics melted into the molten pool of the cladding layer during the laser cladding process， and two different scales of TiC strengthening phases precipitated during the cooling process.The fine TiC phases were dispersed in the cladding layer， effectively inhibiting the grain coarsening within the microstructure， while the coarse blocky TiC aggregated together to form hard phase particles.The two different scales of TiC significantly enhanced the hardness and wear resistance of the cladding layer.The average microhardness of the TiC strengthened Ni60 composite cladding layer reached 869.5 HV0.2， which was 2.03 times that of Cr12MoV cold work die steel.The strengthening effect of TiC at different scales effectively prevented the micro-cutting action of abrasive particles，thereby enhancing the tribological performance of composite cladding layer.Furthermore， the addition of TiC reduced the friction coefficient of the composite cladding layer， and the wear volume decreased by approximately 86.4%compared with Cr12MoV cold work die steel.The wear mechanisms of the composite cladding layer were mainly abrasive wear and slight adhesive wear.