Investigation On Effects Of Different Additions On Microstructures And Properties Of Cu-W Alloys

Cu-W alloy is widely used as electrical contact material in various high voltage interrupters and as electrode material for electrical discharge machining, due to its advantages of high strength, excellent resistance to arc erosion and to welding. By means of powder metallurgy-infiltration, a series of Cu-W alloys added respectively with carbides and rare earth oxides were prepared in this paper. The effects of different additions with different content on microstructures and properties including the static property and the vacuum breakdown property of Cu-W alloys were investigated respectively. The results showed:1. In the range of 0%-1.5% (wt %) WC addition, the hardness of Cu-W alloys showed increase with increasing percentage of WC, while electric conductivity changed slightly. Distinct decreases were observed from 1.5% to 3.0% WC addition.2. For Cu-W alloys with 0～2%TiC (wt %) additions, while TiC content less than 1.2%, the hardness of alloys showed increase with increasing percentage of TiC, the electric conductivity changed slightly. While the weight fraction of TiC reached 1.2%, Cu-W alloy achieves the best overall property. The hardness and electric conductivity of alloys with higher content of TiC addition were decreased dramatically.3. In the range of 0%-0.5% (wt %) CeO₂ addition, the hardness of Cu-W alloys showed increase with increasing percentage of CeO₂, however, the electric conductivity changed slightly. Distinct decreases were observed from 0.5% to 1.5% CeO₂ addition.4. For Cu-W alloys with 0～1.2%Y₂O₃ (wt %) additions, while Y₂O₃ content less than 0.4%, the hardness of alloys showed increase with increasing percentage of Y₂O₃, the electric conductivity changed slightly. While the weight fraction of Y₂O₃ reached 1.2%, Cu-W alloy achieved the best overall property. The hardness and electric conductivity of alloys with more than 1.2% Y₂O₃ addition are decreased dramatically.5. In the four kinds of Cu-W alloys with suitable content of WC, TiC, CeO₂. Y₂O₃ added respectively, the size of the tungsten particles decreased because these dispersion-strengthened...