表面改性WC颗粒增强铜基复合材料的微观结构与摩擦学特性  

Microstructure and Tribological Performance of Cu Matrix Composites Reinforced with Cu-modified WC Particles

作　　者：徐宇轩 王兴 郭跃芬 周海滨 周佩禹 康丽 邓敏文 姚萍屏[1] XU Yuxuan;WANG Xing;GUO Yuefen;ZHOU Haibin;ZHOU Peiyu;KANG Li;DENG Minwen;YAO Pingping(College of Powder Metallurgy,Central South University,Changsha 410083,China;Institute of Material Science and Engineering,Central South of Forestry and Technology,Changsha 410004,China)

机构地区：[1]中南大学粉末冶金研究院,长沙410083 [2]中南林业科技大学材料科学与工程学院,长沙410004

出　　处：《中国表面工程》2024年第3期165-174,共10页China Surface Engineering

基　　金：国家自然科学基金(52175209)。

摘　　要：WC与Cu界面结合强度不足严重影响铜基复合材料的摩擦磨损性能,但业内尚未有良好的界面调控措施以优化性能。采用铜表面改性WC颗粒改善WC与Cu基体界面,经粉末冶金工艺制备Cu改性WC颗粒增强铜基复合材料,开展复合材料的微结构表征与摩擦学性能研究。研究表明,Cu改性WC颗粒可良好地嵌入铜基体,颗粒与Cu基体界面较基体弹性恢复能力提升33%,硬度提升20%。15 wt.%Cu改性WC增强铜基复合材料具有最佳的物理性能与摩擦学特性,较纯铜粉末冶金材料体积密度提升8%,布氏硬度提升15%,摩擦因数波动幅度最小并稳定在0.75,磨损量最小为0.075 mm^(3),磨痕轮廓圆滑,磨损面最完整且大面积成膜。随Cu改性WC含量增大,主要磨损机制由黏着磨损转变为剥离磨损,Cu改性WC颗粒促进摩擦转移层的形成,抑制磨损面裂纹的横向扩展。Cu改性WC颗粒与铜基体界面结合强度显著提升,15 wt.%复合材料抑制黏着磨损与疲劳磨损,摩擦学性能优异。采用Cu改性WC颗粒增强铜基摩擦材料有望成为优化WC与Cu基体界面提升铜基复合材料摩擦学性能的重要备选途径。Tungsten carbide(WC)particle-reinforced composites are widely used owing to their excellent mechanical properties.The limited solubility of WC in Cu and the weak mechanical interface between the WC particles and the Cu matrix are the main factors contributing to the suboptimal tribological performance of these composites.To address this issue,the surface modification of WC particles is crucial for optimizing the interface and enhancing the bonding strength between the particles and the matrix.In this study,porous spherical WC particles were modified with Cu via spraying and sintering.Cu matrix composites reinforced with five different amounts of Cu-modified WC particles(0 and 5 wt.%,10 wt.%,15 wt.%,20 wt.%,and 25 wt.%)were prepared using a powder metallurgy technique.The mechanical and tribological properties of the Cu matrix composites were tested using a hardness tester and a UMT3 friction tester.Nanoindentation and scanning electron microscope(SEM)line scanning were used to characterize the interface of the Cu-mdified WC particles and Cu matrix.Macro-and microstructural characterization and tribological performance analysis were performed on Cu matrix composites reinforced with Cu-modified WC particles.The results of this study indicate that the Cu-modified WC particles were effectively embedded in the Cu matrix,resulting in the formation of a submicron diffusion layer at the interface between the modified particles and the matrix.This modification process led to a 33%increase in elastic resilience and a 20%increase in hardness at the interface.Microcracks within the particles as well as between the particles and Cu matrix contribute to an increase in porosity.Among the tested composites,the Cu-matrix composite reinforced with 15 wt.%Cu-modified WC particles exhibited superior tribological performance.The friction coefficients of this composite showed minimal fluctuations,stabilizing at approximately 0.75,with wear volumes decreasing to 0.075 mm^(3).The worn surfaces of 15 wt.%Cu-modified WC reinforced composi

关 键 词：Cu改性WC 铜基复合材料 界面 微观结构 摩擦学性能 

分 类 号：TG156[金属学及工艺—热处理] TB114[金属学及工艺—金属学]