机械合金化纳米晶Cu-5% Cr粉末的热静液挤压研究

Study on hot-hydrostatic extrusion of mechanically alloyed nanocrystalline Cu-5% Cr powders

采用机械合金化制备了纳米晶Cu-5%(质量分数,下同)Cr粉末,然后对其进行了热压制坯和热静液挤压致密化研究。结果表明,经10h高能球磨,Cu-5%Cr粉末中Cu的晶粒尺寸细化到约50nm,成为纳米晶粉末。采用热压制坯和热静液挤压工艺可以使纳米晶Cu-5%Cr粉末接近完全致密化。球磨10h的Cu-5%Cr合金粉末经400℃热压制坯和600℃、挤压比为4的热静液挤压后相对密度达到99.3%。热静液挤压致密化后的Cu-5%Cr合金的晶粒有所长大,Cu基体的平均晶粒尺寸达到了500nm左右,变成了亚微米晶材料。该亚微米晶Cu-5%Cr合金具有较好的性能。

Nanocrystalline Cu-5%Cr powders have been prepared by mechanical alloying,and then the consolidation through hot-compaction and hot-hydrostatic extrusion has been investigated.The results show that,the grain size of Cu in Cu-5%Cr powders has been refined to be about 50nm and nanocrystalline powders have been obtained after high energy mechanical milling for 10h.The nanocrystalline Cu-5%Cr powders can be near fully densified by hot-compaction and hot-hydrostatic extrusion.The relative density of the billet of Cu-5%Cr powders milled for 10h attained 99.3% after being hot-compacted at 400℃ and hot-hydrostatic extruded at 600℃ with extrusion ratio of 4.The grains of Cu-5%Cr have grown up in some extent after hot-hydrostatic extrusion.The average grain size of Cu matrix attained about 500nm,and submicron crystalline material has been obtained.The submicron crystalline Cu-5%Cr alloy has better properties.