选择性相强化对CuCr触头材料在真空小间隙中耐电压强度的影响

研究了合金元素Ｗ、Ｃｏ的加入对ＣｕＣｒ触头材料在真空小间隙中耐电压强度的影响。研究结果表明，合金元素选择强化ＣｕＣｒ材料的Ｃｒ相能够显著提触头间隙的耐电压强度，而强化Ｃｕ相对间隙的耐电压强度没有明显作用。文章认为制备ＣｕＣｒ系触头材料时应选择适当的制备工艺，使合金元素能够选择强化材料中的Ｃｒ相。

EFFECT OF SELECTIVE STRENGTHENING OF CuCr CONTACT MATERIALS ON THE DIELECTRIC STRENGTH IN A SHORT VACUUM GAP

The influence of additions of tungsten and cobalt alloying elements into CuCr contact materials on the dielectric strength in short vacuum gaps is studied. The CuCr type contact materials, chromium alloys and copper alloys were prepared by different methods and their breakdown fields in vacuum gaps were measured. The microstructure of the various materials was also analyzed by a Scanning Electron Microscopy (SEM) and energy dispersion X-ray (EDX). Experimental results show that the dielectric strength increases significantly when the Cr phase is selectively strengthened. On the contrary, the selective strengthening of copper phase can not contribute to the dielectric strength. The strengthening mechanism of alloying elements is analyzed and the proper preparation method that determines the distribution of alloying element is also suggested in this paper.