(昆明贵金属研究所 稀贵金属综合利用新技术国家重点实验室，昆明 650106)
摘 要: AgNi触头是一种工业上应用最广泛的电接触材料。采用粉末冶金方法制备了不同Ni含量的AgNi电接触材料，在直流阻性负载条件下(24 V，20 A，DC)测试触点电弧侵蚀行为。利用扫描电子显微镜、力学性能测试以及电接触测试系统研究Ni含量对AgNi触头材料的微观组织、电弧侵蚀形貌、力学性能、电接触性能的影响，揭示AgNi触头的电弧侵蚀机理。结果表明： Ni在Ag基体中呈纤维状弥散分布，随着Ni含量增加AgNi材料的强度和电阻率都增大，但塑性下降；随着Ni含量增加，AgNi触点接触电阻显著增加，抗熔焊性能下降。AgNi触点燃弧时间随Ni含量增加波动增大，但平均燃弧时间和燃弧能量没有明显增大，AgNi30的最大燃弧能量随分断次数增加明显。除了AgNi10以外，AgNi触点材料转移方向为阳极向阴极转移，转移量随Ni含量增加先增大后减小，电弧侵蚀后触点形貌为阳极形成凹坑而阴极形成凸点，且随着Ni含量增加，凹坑和凸点大而集中。
关键字: AgNi电接触材料；电弧侵蚀；接触电阻；燃弧时间；材料转移
（State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute of Precious Metals, Kunming 650106, China）
Abstract:AgNi contacts are the most widely used electric contact materials. AgNi electric contact materials with different Ni contents were fabricated using powder metallurgy method, and the arc erosion behavior of the contacts was tested under a DC resistive load (24 V, 20 A, DC). The effects of Ni content on the microstructure, arc erosion morphology, mechanical performance, and electrical contact performance were systematacially studied by SEM, mechanical property testing, and electrical contact test system. The arc erosion mechanism was discussed. The results show that Ni disperses in the Ag substrate as fibers. With the increase of Ni content, the AgNi materials show an increasing strength and electrical resistivity while a decreasing plasticity. The contact resistance increases significantly and the welding resistance decline for the AgNi contacts. Fluctuation of the arc time increases with increasing the Ni content, while the average arc time and arc energy show no obvious increment. The maximum arc energy of AgNi30 increases obviously along with the operation number. Except for the AgNi10, material transfers from the anode to the cathode, with the mass change first increases then decreases when the Ni content increases. A pit on the anode surface and a bump on the cathode surface are formed after erosion. The pit and bump become larger and more lumped with increasing the Ni content.
Key words: AgNi electric contact material; arc erosion; contact resistance; arc time; material transfer
