AgSnO2NiO电触头材料电接触性能的研究

Electrical Contact Properties of AgSnO2NiO Electrical Contact Material

摘要:

采用合金内氧化法制备了不同NiO含量的AgSnO₂NiO电触头材料,在JF04C触点材料测试机上对材料进行电接触实验,研究了该材料的接触电阻、抗熔焊性、材料转移特性,并通过扫描电镜对试样阴/阳极表面电侵蚀下的微观形貌进行了分析。结果表明,NiO的加入有利于减小并稳定接触电阻,电压不高于18 V时,接触电阻随开闭次数的增加呈现出缓慢下降最后趋于稳定的趋势,而当测试电压增大到25 V时,各试样的接触电阻随之增大,且各试样接触电阻的增幅不同；材料的熔焊力和燃弧能量均随电压的增加而增大,NiO含量的增加并不会明显降低熔焊力,但起到了减小燃弧能量的作用。电接触过程材料为阳极转移,材料总损耗量随NiO的加入量增多而降低,阴极触头表面明显附有一层凝固后的熔融金属液形貌,材料转移主要以熔桥方式进行,且凸峰表面呈现浆糊状尖峰的形貌特征。

关键词:AgSnO₂NiO复合材料;合金内氧化;接触电阻;抗熔焊性;材料转移

Abstract:

AgSnO₂NiO electrical contacts with different NiO contents were prepared by internal oxidation method. Electrical contact experiments were conducted on the JF04C contact material testing machine. The contact resistance, anti-weldability and material transfer properties of materials were studied. The sample surface morphology changes were analyzed by scanning electron microscopy (SEM). The results show that the addition of NiO is beneficial to reduce and stabilize the contact resistance. When the voltage is not higher than 18 V, the contact resistance gradually decreases with the increase of test times and finally tends to be stable. When the voltage reaches 25 V, the contact resistance of materials will increases, and the increased degree of the contact resistance is different. Both the welding power and the arcing energy of the material will increase with the voltage increases. The increase of the NiO content does not significantly reduce the melting, but it played a important role in reducing the arc energy. The electrical contact process is anodic transfer. The total mass loss of materials decreases with the increase of NiO contact. The surface of the cathode is obviously accompanied by a layer of solidified molten metal. The material transfer is mainly carried out by a fused-bridge mode with a convex peak. The surface exhibits a paste-like peak topography.

Key words:AgSnO₂NiO; internal oxidation; contact electrical resistance; welding resistance force; material transfer