真空开关触头材料低截流、高抗焊的理论研究

A Theoretical Study on Chopping Current and fusion Welding Resistance of Contact Materials for Vacuum Switches

分析了触头截流产生机理，研究了截流与熔焊模型，讨论了触头材料特性与触头截流、熔焊的定量关系。研究结果表明，低截流与高抗焊在对触头材料性质的要求上不尽相同。增大材料的值对提高触头的抗熔焊能力和降低截流均有益处；但减小ｍａ仅仅对降低截流有利，却易于造成熔焊发生。

The current chopping mechanism and its mathematical moddare investigated and thequantitative relation between material properties and contact chopping and fusion welding resistance are discussed.The results of theoretical prediction and previous experiments onchopping current for Cd,Sn,Zn,C,Ag,Cu,Mo,and W are compared. It is shown that thereexist identical and contradictory demands on the material properties for lower chopping cur-rent and higher ability against fusion welding,Increasing the value of will be advantageousto both indices while decreasing the values of,Cp,λ,θb,and ma is only significant for re-ducing the chopping current but will make it easier for fusion welding to occur.