AgW is one kind of silver-base electrical contact materials with tungsten frame which is produced by powder metallurgy method. It combines the excellent thermal and electrical conductivities of silver and the high melting point and small burning loss of tungsten. It has high hardness, low mechanical abrasion, excellent arc erosion resistance and fusion welding resistance. The AgW material has high brazed area ratio and welding strength, the small size contact can be used in automotive welding, and the large size contact with brazing material is easy and efficient to weld.
AgW contact materials are generally prepared by powder infiltration method, and also can be prepared by power sintering method according to the material usage requirements. AgW contact materials prepared by power sintering method do not only have the features of low resistivity, high melting point and ablation resistance of AgW-type products, but also have the advantages of unique optional welding layer materials and single compound of power sintering process. Meanwhile, for AgW-type materials prepared by this processing process, there is no pure silver layer on the working surface. This is beneficial to improve the breaking capacity of contacts, and they can be used as static contacts.
（一）Structure and application