| Laser cladding technology, as a way to improve the performance of the metal surface, which can effectively improve the hardness, wear resistance and corrosion resistance of parts, has wide application prospect. Therefore, the study of coating forming process and coating properties is very meaningful. This paper expounds the methods and characteristics of laser cladding technology, analyzes the formation mechanism of laser cladding coating crack, and studies the fusing mechanism of molten pool and metal materials under the effect of laser. Through the process experiment, high rigid Ni capped WC coating was prepared, and have a systematic analysis and research of the coating microstructure morphology and composition, coating hardness, wear resistance coating were carried on. The main research content is as follows:(1) From the fusing mechanism of metal materials under the effect of laser, the laser cladding of the molten pool formation and mechanism of crack formation were studied, providing certain theoretical basis for process test.(2) By orthogonal experiment of laser power, scanning rate, preheat temperature and other process parameters, lots of Ni capped WC coating was processed, and the analysis for various process parameters on the coating and the influence of the crack sensitivity were conducted.(3) Research on coating microstructure morphology by SEM, EDS and XRD testing and analysis of the composition and phase composition of coatings, the effect of process parameters on the microstructure at the same time were also carried on.(4) The coating hardness was studied, including analying the influence of process parameters on the coating micro hardness and the micro hardness distribution of coating with different depth.(5) For testing coating wear resistance, wear resistance of different hardness of coating and substrate materials are compared through the friction coefficient and wear volume and wear morphology difference, and the result was simply analyzed. |
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