Research On Microstructure And Properties Of W-40wt%.Cu Alloy By Hot Extrusion-swaging Plastic Deformation Technology

Tungsten-copper composite is composed of tungsten and copper, which hasexcellent performance, such as high thermal and electric conductivity, arc ablationresistance, high temperature resistance, high strength, high hardness and low thermalexpansion coefficient. And it is widely used in electrical, electronic, military and otherfields. However, both the difficult densification process and the poor plasticity restrictthe preparation and the application of different specification tungsten-coppercomposites with excellent performance.Based on the characteristic of tungsten-copper composite, the thermoplasticprocess technology about the slender rod of W-40wt.%Cu composite is researched inthis paper. The purpose is to obtain the slender rod and the wire, meanwhile to improvethe electrical conductivity, hardness and relative density by plastic deformation of hotextrusion and rotary swaging process. These would improve the comprehensiveproperties, reduce cost, save resources, and enrich the preparation technology andtheory of tungsten-copper composite.First, the rods with11.08mm diameter of W-40wt.%Cu, W-30wt.%Cu,W-20wt.%Cu, and W-10wt.%Cu composite can be preparation by liquid phase sinteringand solid extrusion. The extruded tungsten-copper composite has higher relative density,relatively homogeneous microstructure, and the electrical conductivity and the hardnessare higher than government standard about electrical contact material.Second, heat treatment experiment about tungsten-copper composite of differentcomposition is researched. As a result, the comprehensive properties can be the best,when the four composition tungsten-copper composites are heated to850℃and holdthat temperature for2hours. Relative to the extruded tungsten-copper composite, theelectrical conductivity rises. And the hardness reduces, but it is still higher than thegovernment standard.Then, it is researched about the extruded W-40wt.%Cu composite on rotaryswaging technology. The tungsten-copper composites with diameter of4.46mm,5.52mm,6.84mm,8.26mm and9.64mm are prepared. And the influence of thetemperature and the accumulated deformation amount is analyzed. As a result, the bestswaging temperature is950℃.When swaged at this temperature, the tungsten-coppercomposite has homogeneous microstructural and excellent properties which are higherthan the government standard.Finally, based on the electrical conductivity of tungsten-copper composite reducingafter swaged, heat treatment for swaged W-40wt.%Cu composite with72.30% accumulated deformation amount is researched. As a result, when the swagedtungsten-copper composite is heated to700℃and hold that temperature for2hours,the comprehensive properties can be the best. And when the swaged tungsten-coppercomposite is heated to1000℃and hold that temperature for8hours, the electricalconductivity rises obviously, the hardness is lower than the government standard.