Erosion of silver-base material contacts by breaking arcs

The mechanisms of material erosion of Ag-base material contacts caused by breaking arcs up to several hundred amperes are studied. The experiments breaking AC and half-wave sinusoidal current were carried out. The factors influencing the contact erosion are analyzed; it is suggested that the electrode erosion should be the result of the heat force effects among arc, electrodes, and environment. The main cause of obvious material transfer is the asymmetry of the heat force effects at two electrodes. It is indicated that there are two forms of liquid ejection: edge ejection and center ejection. The erosion modes are divided into several different modes, and each is detailed. A mode diagram is given, and the erosion features of Ag-base materials are described