Q235表面激光熔覆原位TiC/Ni复合层显微组织研究

Microstructure and Properties of TiC/Ni Composite Coating Prepared with Laser Clad on Q235 Steel Substrate

采用CO2激光器在Q235钢基体表面激光原位合成TiC/Ni复合涂层;借助于扫描电镜(SEM)、X射线衍射仪(XRD)、能谱仪(EDS)、显微硬度计、ML-100型磨粒磨损试验机对涂层组织结构、物相、组成成分、硬度及耐磨性能进行了分析。结果表明:在Q235表面激光熔覆(Ni+Ti+C)混合粉末原位制备出了TiC/Ni复合陶瓷涂层,涂层组织细密、无裂纹、气孔且与基体呈良好的冶金结合,TiC颗粒呈现块状和花瓣状组织;从表层到底部TiC颗粒数量逐渐减少;添加Ti和C的复合涂层较镍基激光熔覆层,其显微硬度和耐磨性能都得到了一定的提高。

The TiC/Ni composite coating was in situ synthesized on Q235 substrate by agreat power CO2 laser.The microstructure,phase constitution,micro-hardness,wear resistance of TiC/Ni composite coating were examined by SEM,XRD,EDS,micro-hardness tester and ML-100 abrasion tester.The results reveal that utilizing the high temperature chemical reaction between Ni,Ti,C powders,TiC/Ni composite coating can be in situ synthesized on Q235 substrate by laser cladding.The coating has denser structure,free of pores and cracks.An excellent bonding between the coating and the substrate can be ensured by the strong metallurgical interface.The massive,flower-like,accumulated TiC particles are formed and the number of particles decreases from surface to bottom.The composite coating added Ti and C has higher micro-hardness and better wear resistance compared with Ni-based coating prepared by laser cladding.