(Department of Materials Science and Engineering, Sharif University of Technology,
Tehran, P. O. Box 11155-9466, Iran)
摘 要: 采用放电等离子烧结制备钇稳定氧化锆(YSZ)增强铜基复合材料。为作比较，在相同条件下制备了纯铜样品。研究了粒子含量对复合材料显微组织、相对密度、电导率和维氏硬度的影响。利用销-盘装置研究材料在不同条件下的干滑动摩擦行为。干滑动摩擦测试后，采用场发射扫描电子显微镜对磨损表面进行观察。显微组织结果表明增强粒子在铜基体中分布均匀。所有样品的相对密度都达到95%以上。当YSZ含量从0增加至5%(体积分数)时，材料的电导率从99.2%IACS 降至65%IACS。Cu-5%YSZ复合材料的硬度比纯铜硬度大两倍。在加载载荷为50 N和滑动距离为1000 m条件下，纯铜的体积损失和磨损率分别为1.48 mm3和1.5×10-3 mm3/m。而对于5% YSZ增强的复合材料，其体积损失和磨损率分别降至0.97 mm3和0.9×10-3 mm3/m。此外，材料的摩擦因数从0.6降至0.4。磨损表面和磨粒观察结果表明纯铜的磨损机理为塑形变形和分层，而对于复合材料，磨损机理为氧化和犁沟。因此，Cu-YSZ复合材料可用于要求具有高电导率和热导率以及耐磨性能的继电器、电流接触器，开关和断路器。
关键字: 铜基复合材料；放电离子烧结；显微组织；电导率；滑动摩擦
（Department of Materials Science and Engineering, Sharif University of Technology, Tehran, P. O. Box 11155-9466, Iran）
Abstract:In the present study, yttria stabilized zirconia (YSZ) reinforced Cu matrix composite specimens were produced by spark plasma sintering (SPS). For comparison, pure Cu specimen was also produced in the same conditions. The effect of particles content on microstructure, relative density, electrical conductivity, and Vickers hardness was evaluated. The pin-on-disk test was also performed to determine dry sliding wear behavior of specimens under different wear conditions. After sliding wear tests, the worn surfaces were examined by field emission scanning electron microscopy (FE-SEM). Microstructural study showed satisfactory distribution of reinforcement particles in copper matrix. The relative density up to 95% was obtained for all specimens. By increasing YSZ content from 0 to 5% (volume fraction), the electrical conductivity of specimens decreased from 99.2%IACS to 65%IACS, correspondingly. The hardness of Cu-5%YSZ composite specimen was two times greater than that of pure copper. The volume loss and wear rate of pure Cu specimen were 1.48 mm3 and 1.5×10-3 mm3/m under 50 N applied load and 1000 m sliding distance. However, for composite containing 5% YSZ particles, these values dropped to 0.97 mm3 and 0.9×10-3 mm3/m, respectively. Moreover, the friction coefficient of specimens was changed from 0.6 to 0.4. The worn surface and debris observation indicate local plastic deformation and delamination as dominant wear mechanisms for pure copper, while oxidation and ploughing for composite specimen. Accordingly, it can be concluded that the Cu-YSZ composite could be a good candidate for the electrical contact applications in relays, contactors, switches and circuit breakers requiring good electrical and thermal conductivity and capability to resist wearing.
Key words: copper matrix composite; spark plasma sintering; microstructure; electrical conductivity; sliding wear
