Study On Densification Technology Of W-Cu Composites In Different Ratio Of Constituents

With excellent thermal and electricity behavior, high strength and hardness, W-Cu composites have been used widely in the fields of electrical materials, electron, ordnance industry and spaceflight. Along with the further progress on the electronic industrial, the need of high performance W-Cu composite is more and more urgently. However, because of the mutual insolubility between W and Cu, it is difficult to get densified W-Cu composites by traditional methods. In this dissertation, ball milling and plastic deformation techniques are used to prepare high performance W-Cu composites.In this paper, W-Cu composites with different percentage composition of Cu (such as W-20wt.%Cu, W-30wt.%Cu, W-40wt.%Cu and W-50wt.%Cu) were studied. Then the high-density, fine-structure and good-quality composites were fabricated with the techniques of mechanical mixing, cold pressing, liquid sintering, twice hot extrusion and hot rolling.Firstly, the billet was obtained by powders mixing with short time and cold-pressing. Then the conductivity and hardness of W-Cu composites fabricated by liquid-phase sintering and first extrusion were analyzed. At the same time, the effect of copper content on performance of W-Cu composites was also researched. Secondly, twice extrusion and hot rolling techniques of extruded billets were studied in order to find the effect of twice plastic deformation on the main performance of W-Cu composites. Finally, heat-treatment was used to improve the comprehensive performance of deformed billets with different plastic deformation techniques.From above, conclusions can be drawn as followed. The deformation behavior of copper phase was obvious with the increasing of copper content during plastic deformation. However, the deformation behavior of tungsten particles was evident with the increasing of tungsten content during plastic deformation. After twice extrusion, the densification of W-Cu composites was increased, and which electric conductivity and hardness were improved. Of course, not only the electric conductivity and hardness of W-Cu composites by extrusion and hot rolling were improved, but also rods and sheets of W-Cu composites can be fabricated according to the need of engineering applications.