金刚石粒径及含量对超音速激光沉积金刚石/Cu复合涂层微观结构及性能的影响

Influence of Diamond Particle Size and Content on the Microstructure and Properties of Diamond/Cu Composite Coating Prepared by Supersonic Laser Deposition

目的研究不同金刚石粒径及含量对超音速激光沉积金刚石/Cu复合涂层微观结构及性能的影响。方法利用超音速激光沉积技术制备金刚石/Cu复合涂层。采用扫描电镜和摩擦磨损测试对涂层的显微组织结构和磨损性能进行了分析,用激光闪烁法测量复合涂层的热导率。结果金刚石均匀分布在复合涂层中,原始粉末中金刚石体积分数从30%增加到50%时,复合涂层中金刚石颗粒的面积占比仅从14.01%升至16.79%,远低于金刚石颗粒在原始粉末中的含量。400目金刚石/Cu复合涂层的平均热导率为296 W/(m·K),摩擦系数为0.551;800目金刚石/Cu复合涂层的平均热导率为238 W/(m·K),摩擦系数为0.545。结论原始粉末中金刚石配比的增加并未对复合涂层中金刚石含量的提升有显著作用。金刚石/Cu复合涂层的热导率随着增强相颗粒含量的增加而降低,随着增强相颗粒粒径的增大而提高。不同粒径金刚石颗粒的添加能显著降低Cu涂层的摩擦系数,且小粒径金刚石颗粒的添加使复合涂层的摩擦系数更低和更稳定,从而使其具有更小的磨损量和磨痕宽度,表现出较优的耐磨损性能。

The work aims to study the effects of different diamond particle sizes and contents on the microstructure and properties of diamond/Cu composite coatings prepared by supersonic laser deposition.The microstructure and wear properties of the coatings were analyzed by scanning electron microscopy and friction and wear test.The thermal conductivity of the composite coating was measured by laser scintillation.The diamond particles were evenly distributed in the composite coating.When the content of 800-mesh diamond particles in the original composite powder increased from 30%to 50%,the area ratio of diamond particles in the composite coating only increased from 14.01%to 16.79%,which was much lower than that of the diamond particles in the original composite powder.The average thermal conductivity and friction coefficient of the 400-mesh diamond/Cu composite coating were 296 W/(m·K)and 0.551,respectively;and the average thermal conductivity and friction coefficient of the 800-mesh diamond/Cu composite coating were 238 W/(m·K)and 0.545.The increase of diamond ratio in the original composite powder does not have a significant effect on the increase of diamond content in the composite coating.The thermal conductivity of the diamond/Cu composite coating decreases as the content of the diamond particles increases,and increases as the particle size of the diamond particles increases.The addition of diamond of different particle sizes can significantly reduce the friction coefficient of the Cu coating,and the diamond in smaller size can make the friction coefficient much lower and the coating more stable and then lead to lower wear amount and smaller scar width,so that the excellent wear resistance is obtained.