为提高金属材料表面涂层的耐磨性,采用激光熔覆工艺制备了Al₂O₃增强Fe901金属陶瓷复合涂层,研究了Al₂O₃陶瓷增强相对Fe基熔覆层组织与性能的影响。利用扫描电镜和X射线衍射仪检测了复合涂层的微观组织和物相;采用显微硬度仪和摩擦磨损试验机分析了复合涂层的显微硬度与耐磨性。结果表明: Fe901涂层的组织以柱状枝晶和等轴枝晶为主,添加的Al₂O₃可促使涂层组织转变为均匀的白色网状晶间组织及其包裹的细小黑色晶粒;复合涂层中的Al₂O₃陶瓷颗粒表面发生微熔,与Fe、Cr结合生成Fe₃Al及(Al, Fe)₄Cr金属间化合物,起到增加Al₂O₃陶瓷颗粒与金属黏结相结合强度的作用;当Al₂O₃陶瓷颗粒的质量分数为10%时,复合涂层的显微硬度较Fe901涂层增加了16.4%,复合涂层的摩擦磨损质量损失较Fe901涂层降低了50%;添加适量的Al₂O₃陶瓷有助于提高涂层的显微硬度及耐磨性。

Al2O3-reinforced Fe901 metal-ceramic composite coatings were prepared by laser cladding to improve the wear resistance of surface coating of metal materials. This study investigated the effect of Al2O3-reinforced phase on the microstructure and properties of a Fe-based cladding layer. The microstructural evolution, phase compositions, wear resistance, and microhardness of the composite coatings were studied using scanning electron microscopy, X-ray diffraction, friction and wear tester, as well as microhardness tester, respectively. The results show that the microstructure of the Fe901 coating was dominated by columnar and equiaxed dendrites. In addition, the addition of Al2O3 promoted the transformation of microstructure into a uniformly distributed white network-like intergranular structure with wrapped fine black grains. The surface of Al2O3 ceramic particles micro-melted and combined with Fe and Cr to form Fe3Al and (Al, Fe)4Cr intermetallic compounds within the composite coating, which increased the bond strength between Al2O3 ceramic particles and the metal phase. When the mass fraction of Al2O3 ceramic particles is 10%, the microhardness of the composite coating is increased by 16.4%, and the mass loss in the composite coating is reduced by 50% compared to that of the Fe901 coating. Thus, adding an adequate amount of Al2O3 ceramics can improve the microhardness and wear resistance of coatings.