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探讨了激光熔覆TiC4复合陶瓷涂层微观结构特征,研究了氧化铈对涂层显微组织、显微硬度及摩擦学性能的影响.在45#钢基体上制作了Ni、Cr、TiC4复合陶瓷涂层及氧化铈改性的复合涂层,用X射线衍射仪(XRD)、分析型扫描电镜(ASEM)、显微硬度计及摩擦磨损试验机对涂层组成、显微组织、显微硬度及摩擦学性能进行了分析.结果表明:利用激光熔覆方法制作的TiC4陶瓷层具有典型的包覆相和硬质点相结构,加入适量的氧化铈能有效防止TiC4结晶过程中颗粒桥接,阻止TiC4结晶成枝状结构,细化了TiC4颗粒,同时也使其分布更加离散.当添加氧化铈的质量分数为0.50%～3.0%时,TiC4颗粒离散效果最好,此时涂层显微硬度分布均匀,较不添加氧化铈涂层相比,显微硬度提高了10%左右,当添加氧化铈的质量分数超过4.0%,TiC4颗粒发生桥接,成枝状结构,且出现聚集,硬度分布离散度加大.磨损试验结果表明氧化铈能改善涂层的干摩擦特性,有效防止涂层片层状脱落,但对涂层耐磨性没有明显的改进,涂层呈现黏着磨损特征.
The microstructure of the laser cladding TiC4 composite ceramic coating was investigated and the effect of cerium oxide on the microstructure, microhardness and tribological properties of the coating was studied.Ni, Cr and TiC4 composite ceramics Coating and cerium oxide modified composite coatings were characterized by X-ray diffraction (XRD), analytical scanning electron microscopy (ASEM), microhardness tester and friction and wear tester on the composition, microstructure, microhardness And tribological properties of the TiC4 ceramic coatings were analyzed.The results show that the TiC4 ceramic coating prepared by laser cladding has the typical coating phase and hard point phase structure, adding appropriate amount of cerium oxide can effectively prevent the particles from bridging during the crystallization of TiC4 TiC4 crystallized into a dendritic structure, refined TiC4 particles, but also to make its distribution more discrete when the mass fraction of cerium oxide added 0.50% ~ 3.0%, TiC4 particles the best dispersion, the coating hardness Compared with no cerium oxide coating, the microhardness increased by about 10%. When the mass fraction of cerium oxide added exceeds 4.0%, the TiC4 particles bridge and dendritic structure with aggregates and discrete hardness distribution Increased degree of abrasion test Showed that cerium oxide can improve the dry friction properties of the coating, the coating effectively prevents the lamellar off, but without significant improvement of the wear resistance of the coating, the coating exhibits adhesive wear characteristics.