显微组织对CuCr真空触头材料耐电压强度的影响

研究了ＣｕＣｒ真空触头合金的显微组织对其耐电压强度的影响，研究结果表明，电击穿总是首先发生在耐电压强度低的合金相上，对Ｃｕ５０Ｃｒ５０合金，首击穿相为Ｃｒ相，而对ＣｕＣｒ５０Ｓｅｌ合金，首击穿相为Ｃｕ２Ｓｅ相．由于电压老炼的结果，首击穿相的耐电压强度上升而导致其他合金相被击穿，老炼的结果使原始粗大的合金相消失，在表层形成成分均匀的极细小显微组织，还从物理冶金学出发讨论了电压老炼的作用，认为电压老炼的过程实质上是一个在表层形成极细小显微组织和成分均匀化的高速相变过程．

THE EFFCT OF MICROSTRUCTURE OF CuCr CONTACT MATERIAL ON THE DIELECTRIC CSTRENGTH IN VACUUM

In the present work the influence of microstructure of CuCr contact materials on dielec-tric strength in vacuum is investigated.Experimental results show that breakdown selective-ly occurs on dielectrically weak phase. For Cu50Cr50 alloy,it firstly takes place on Cr parti-cles,and for CuCr50Sel alloy,on Cu2Se phase. As a result of conditioning of breakdown,the dielectric strength of these phases increases,breakdown occurs both on these phases andother phases simultaneously.Breakdown roughens the surface of cathode,but produces asmall melt laver on the surface which has much fine microstructure and more uniform micro-compositions. The role of conditioning of breakdown, from the point of view of physicalmetallurgy,is to produce much fine microstructure and more even micro-compositions whichare very beneficial to increase dielectric strength.