激光熔覆WC/17-4PH复合涂层组织及性能研究

Study on Microstructure and Properties of Laser Cladding WC/17-4PH Composite Coating

采用LaserlineLDF-3000-60型激光器在45钢表面,利用激光熔覆技术,制备不同质量分数的17-4PH+碳化钨(WC)复合涂层。借助光学显微镜、显微硬度计、摩擦磨损测试方法对熔覆层的显微组织、硬度及耐磨性检测及分析。结果表明,熔覆层的平均硬度和磨损量均随WC质量分数的增加呈现梯度增加的趋势。当WC质量分数为25%时,涂层与基材冶金结合良好,组织均匀、致密,无热裂纹及气孔等缺陷,熔覆层平均硬度为497.6 HV,相较于基体提高了153.0%;当WC质量分数为30%时,陶瓷相进一步增多,使得熔覆层出现从涂层表层至基体的贯穿裂纹,涂层硬度相较于基体提高了160.7%,磨损量为基体的26.2%。

Composite coatings of 17-4PH+WC with varying mass fractions were prepared on the surface of 45 steel using the Laserline LDF-3000-60 laser cladding technique.The microstructure,hardness,and wear resistance of the fused cladding layer were examined and analyzed using an optical microscope,microhardness tester,and friction-wear testing method.The results indicate that the average hardness of the fused cladding layer increases with the WC content.When the WC mass fraction is 25%,the coating achieves good metallurgical bonding with the substrate,displaying a uniform and dense structure,free from defects such as thermal cracks and porosity.The average hardness of the fused cladding layer is 497.6 HV,which is 153.0%higher than that of the substrate.When the WC mass fraction is 30%,an increase in the ceramic phase results in the appearance of through-cracks from the coating surface to the substrate,with the coating hardness rising 160.7%compared to the substrate,and wear volume being 26.2%of that of the substrate.These findings suggest that the coating exhibits optimal performance when the WC mass fraction is 25%.