AgSnO2电接触材料熔桥行为的高速摄像研究

High speed imaging observation on molten bridge of AgSnO2 electrical contact material

摘要:

本研究以AgSnO₂电接触材料为研究对象,借助高速摄像技术并与电接触试验机组成电接触-高速摄像试验体系,观测电触头对在不同负载条件下熔桥行为的基本特征和规律,并进行定量测量研究,同时通过扫描电镜(SEM)和能谱分析(EDS)对熔桥行为后触头表面的微观结构和元素分布进行分析。结果表明,AgSnO₂触头熔桥演化行为可分为接触区域熔化、熔桥稳定存在和熔桥失稳及断开三个阶段,熔桥和电弧现象可以同时存在,并且存在一定的协同和竞争关系,AgSnO₂触头材料的熔桥尺寸为微米级(0.027-0.295 mm),熔桥直径随电流的增大而增大,熔桥长度随电流的增大而减小,熔桥演化行为过程中熔桥形状依次表现为墩粗型、圆柱型和哑铃型,熔桥行为会改变触头的表面形貌和元素分布。

Abstract:

In this paper, an electrical contact-high speed imaging experimental system is developed to study the basic characteristics and laws of molten bridges of AgSnO₂ electrical contact material under different loads. On the one hand, the quantitative measurements are investigated by high speed imaging technology. On the other hand, the microstructure and element distribution on the surface of contacts are analyzed by SEM and EDS after molten bridges behavior. Results indicate that the evolution behavior of AgSnO₂ contacts can be divided into three regimes: the initial melting period, a stable period and an unstable period during which it eventually ruptures. Molten bridges and arc can exist simultaneously in which there is some cooperation and competition relationship. The dimension of molten bridges of AgSnO₂ contact material is micron scale (0.027-0.295 mm), the diameter of molten bridges increases with the increase of current and the length decreases with the increase of current. In the process of the evolution behavior of molten bridges, the feature of molten bridges can be divided into three types: the pier, follow by the cylindrical and the dumbbell. The morphology and element distribution of the contacts surface are changed by the behavior of molten bridges.