Ag-30W的电弧行为高速摄像及表面侵蚀研究

Study on Surface Erosion and Arc Erosion Profile of Ag-30W by Using High-speed Imaging Technique

采用高速摄像的方法,研究了直流条件下Ag-30W电接触材料电弧行为的基本特征和规律。通过扫描电镜技术,探讨了在电弧烧蚀触头表面的微观组织形貌、元素分布等特征。结果表明,电弧演化经历快速起弧、稳定燃烧和迅速熄灭3个过程。电弧烧蚀触头表面形貌由以钨为骨架、银为包裹层的大量凸丘组成。在电弧作用下,银包裹层可以有效保护钨骨架不被烧损,同时减少钨与空气的接触,减轻凸丘处电弧燃烧造成的侵蚀。

Arc erosion profile and regularity of Ag-30W, an electrical contact material, were investigated by the high-speed imaging technique along with the measurement of SEM morphology on contact surface under direct current. Results showed that the arc formation at different voltages was similar and underwent three stages including forming stage and steady burning and discharge quenching stage. The convex was observed on the erosion surface of the contacts under scanning electron microscopy （SEM）. The convex was formed in the break off of molten bridge by the W skeleton and Ag cladding. With the continuous erosion by the arc light, Ag cladding would protect the W skeleton from burning loss and oxidative damage, endowing the contact material with an enhanced anti-erosion ability.