激光熔覆原位合成TiC-TiB2增强钴基复合涂层的研究

为了提高零件表面强度和耐磨性,以TiO2,Al,B4C和KF-Co50合金粉末为原料,利用激光熔覆技术,采用预置粉末法,在Q235钢基体表面原位合成了TiC-TiB2增强Co基复合涂层。使用金相显微镜、扫描电镜和X射线衍射仪对熔覆层的组织和物相进行了分析,并对熔覆层的显微硬度及耐磨性能进行了测试。结果表明,熔覆层与基材呈现良好的冶金结合,组织致密,无裂纹、气孔等缺陷;熔覆层的主要组成相有γ-Co,TiC,TiB2,Cr23C6等;熔覆层平均显微硬度达770HV0.2,耐磨性能优异。这一结果对提高零件使用寿命具有积极意义。

Research of in situ synthesis of TiC-TiB2 reinforced Co-based composite coating by laser cladding

In order to increase the surface strength and wear resistance of the parts,TiC-TiB2 reinforced Co-based composite coating was successfully in situ synthesized by laser cladding with preplaced powder method on steel Q235 using TiO2,Al,B4C and KF-Co50 alloy powders as the binding material.The microstructure and phases analysis of the coating were performed with metallographic microscope,scanning electron microscope and X-ray diffractometer.The microhardness and wear resistance of the coating were also tested.The results show that the coating is uniform,continuous and free of pores and cracks.An excellent bonding between the coating and the substrate was ensured by the strong metallurgical interface.The microstructure of the coating is mainly composed of γ-Co,TiC,TiB2 and Cr23C6.The average microhardness of the coating is 770HV0.2 and the coating presents excellent wear resistance.The results have positive significance to improve service life of the parts.