Effects of grading tungsten powders on properties of CuW alloy

Considering the advantages and disadvantages of CuW alloys with different single particle size of tungsten powder, CuW alloys with three kinds of tungsten powders: ultramicron (50 μ m), micron(6–8 μ m), submicron(0.4 μ m) were prepared by the infiltration method. Microstructure of the CuW alloy with different grading ration of tungsten powder were characterized via field-emission scanning electron microscope (SEM). The Vacuum electrical breakdown properties were studied by electrical breakdown test. The results shows that the grading tungsten powders can form a variety of W-W sintered necks, strengthen the tungsten skeleton. SEM results show that a suitable ratio of grading tungsten powders can make the infiltrated copper phase more dispersed and uniform. Compared with the tradition CuW alloy, the conductivity is greater than 53.5%IACS, with the lowest hardness of 203HB, the lowest CuW/CrCu bonding strength of 417 MPa and the highest of 495 MPa, the hardness and electrical conductivity increased by 20%–30%, the bonding strength of new CuW/CrCu monolithic materials increased by 20%, vacuum electrical breakdown properties performed good.