微晶、纳米晶 CuCr 触头材料的组织及性能

Microstructure and Properties of CuCr Contact Materials with Microcrystalline or Nanocrystalline Grains

采用机械合金化的方法制备出 Ｃｕ Ｃｒ 纳米合金粉并分别在９２０ ℃、７５０ ℃及５８０ ℃将合金粉热压烧结得到了微晶、纳米晶 Ｃｕ Ｃｒ 合金。５８０ ℃热压可以得到致密度大于９０ ％ 的纳米晶 Ｃｕ Ｃｒ 块体，７５０ ℃及９２０ ℃热压晶粒长大到微米量级。纳米晶 Ｃｕ Ｃｒ 材料在真空间隙中的耐电压强度接近常规致密、低氧 Ｃｕ Ｃｒ 触头材料的水平。

Abstract: The CuCr alloy powders with nanocrystals were prepared by mechanical alloying technique. The CuCr materials with microcrystalline or nanocrystalline grains were got through consolidation of the milled powders by heat press at 920℃, 750℃ and 580℃ respectively. Experimental results show that the CuCr materials with nanocrystals and more than 90% relative density are achieved when heat pressed at 580℃. The size of grains increases to several micrometers for heat press at 750℃ and 920℃. The dielectric strength of the CuCr materials with nanocrystalline grains in vacuum has approached to that of conventional CuCr contacts.