机械活化热压制备CuCr50触头材料的组织与性能

Microstructures and Properties of CuCr50 Contact Materials Prepared by Mechanically Activated Hot Pressing

采用机械合金化(MA)活化CuCr50粉末,然后对MA粉进行真空热压制备出CuCr50触头材料。结果表明,CuCr50MA粉为亚稳态过饱和固溶体,这种过饱和固溶体在随后的热压过程中发生脱溶现象。随脱溶程度的不同,CuCr50块体材料的组织与性能也发生相应的变化。由于MA活化作用,使得CuCr50MA粉在较低的温度保压较短的时间内便获得了致密度高的块体材料,并且第二相Cr分布均匀,尺寸细小,其综合性能优于其它工艺方法获得的CuCr50触头材料。

CuCr50 powders were first activated by mechanical alloying （MA）, then used to prepare the contact materials by vacuum hot pressing. The results indicate that the CuCr50 powder by MA is ametastabe and supersaturated solid solution, would dissolve during the followed hot pressing. The microstructures and properties of bulk CuCr50 materials vary with the dissolving amounts of supersaturated solid solution. A bulk CuCr50 material of high density with fine and homogeneous Cr particles distributed can be acquired at lower temperature for shorter holding time in hot pressing due to the mechanically activated effect of MA powders. As a result, the synthetical properties of bulk CuCr50 materials fabricated by this method are superior to those prepared by other methods.