| W-Cu composites are important candidate materials for many kinds of electricalmaterial because of their good thermal and electrical conductivity combined with lowthermal expansion coefficient. W-Cu composites produced by infiltration, liquidphase sintering and hot pressing do not have satisfactory complex properties for theirwide use. Therefore, it is necessary to study the manufacturing methods of W-Cucomposites in order to improve their complex properties.W-30Cu composite was prepared by mechanical alloying and liquid phasesintering. The influences of powder particle size, milling time, sintering technique,and annealing temperature on its microstructures and properties were studied.Sintering temperature and holding time have critical effects on themicrostructures and properties of W-30Cu composite. It is shown that specimens withtungsten powder (mean particle size is 15μm) and fine copper powder (mean particlesize is 15μm) sintered at 1200℃for 0.5 h can obtained good complex properties.The density, hardness, conductivity are 98.62%, 287.93HV and 14.2S/m respectively.Powder particle size has effect on sintering temperature. The best sinteringtemperature of specimens with tungsten powder (mean particle size is 15μm) andcoarse copper powder (mean particle size is 75μm) is decreased to 1150℃. Thedensity, hardness, conductivity are 97.80%, 277.78HV, and 15.6S/m respectively.W-30Cu powder with W powder covered by Cu obtained by mechanical alloyingleads to the decrease of sintering temperature and the improvement of complexproperties.Annealing has effects on the electrical conductivity and hardness of W-30Cu.Annealing at 800℃for 1h leads to the increase of the electrical conductivity from15.6 S/m to 16.4S/m Annealing at 900℃for 1h leads to the increase of the hardnessfrom 277.78HV to 299.45HV. |
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