(1. 河南科技大学 材料科学与工程学院，洛阳 471023；
2. 有色金属共性技术河南省协同创新中心，洛阳 471023)
摘 要: 采用真空热压烧结-内氧化法制备Al2O3-Cu/(25)W(5)Cr和Al2O3-Cu/(35)W(5)Cr电触头材料，分别测试其致密度、导电率和布氏硬度；利用场发射扫描电镜分析触头材料的微观组织；利用JF04C电接触触点测试系统研究两种触头材料的电接触性能。结果表明：纳米Al2O3颗粒钉扎位错引起位错缠结；在电弧侵蚀过程中，Al2O3-Cu/(25)W(5)Cr触头在30 A时有少部分材料从阳极转移至阴极，但两种触头材料最终的质量转移方向都是从阴极转移到阳极；电弧侵蚀过程中随着Cu的熔化、蒸发和喷溅，W颗粒逐渐聚集并形成针状的骨架，阳极形成了凸起，阴极留下灼坑；当弥散铜基体中W 的含量从25%增加至35%(质量分数)时，触头的熔焊力下降，抗熔焊性能提高。
关键字: 真空热压烧结；电接触；电弧侵蚀；材料转移；熔焊力
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of Nonferrous Metals, Luoyang 471023, China）
Abstract:The Al2O3-Cu/(25)W(5)Cr and Al2O3-Cu/(35)W(5)Cr composites were prepared by vacuum hot-pressing sintering and internal oxidation methods. Their relative density, electrical conductivity and Brinell hardness were measured, respectively. The microstructure was analyzed by scanning electron microscope. The JF04C electrical contact testing system was used to investigate the welding force and electric contact performance. The results shows that the pining effect of nano-Al2O3 particles causes tangle and intersecting of dislocations. The Al2O3-Cu/(25)W(5)Cr contact has a little mass transfer from the anode to cathode. But the final mass transfer direction of the two composites is from the cathode to anode. With the melting, evaporation and sputtering of Cu, W particles gathers and transforms into needle-shaped skeleton. Finally, pip and crater are presented on the anode and cathode surface, respectively. When the content of W in the dispersed copper matrix increases from 25% to 35% (mass fraction), the welding force reduces obviously.
Key words: hot-pressing sintering; electrical contact; arc erosion; material transfer; welding force
