Electrical contact material
The performance of electrical contact material is one of the key factors affecting the working characteristics and electrical life of vacuum switchgear. Almost all the early vacuum switches used W, Mo and other refractory pure metals as contact materials. This type of contact material has a series of advantages, such as proper breaking capacity, good withstand voltage strength and resistance to fusion welding, proper thermal conductivity and conductivity, low ablation rate during arc burning, long contact service life, etc., and is widely used in breaking small current vacuum switches. However, pure metal contact materials with high melting point have many disadvantages, such as high breaking current and high cut-off level, which limits the application range of vacuum switches.