【摘要】 随着电真空器件的发展,行波管面临着更高的热效应,其收集极受高能电子轰击成为发热最严重的部件之一,直接影响到行波管的工作寿命和稳定性,寻找高导热、低二次电子产额的行波管收集极材料至关重要。本文通过粉末冶金方法制备了一种高取向的石墨/铜复合材料,并对不同石墨含量的复合材料热导率和二次电子发射系数情况进行了研究,发现随着石墨含量的增加,复合材料热导率最大值可以达到733.2 W/(m·K),而二次电子发射系数则随石墨含量增加而减小,石墨含量50%(体积比)的复合材料最大二次电子发射系数为1.11。更多还原

【Abstract】 With the development of vacuum electronic devices, travelling-wave tubes（TWTs） are faced with higher thermal effect. The collector hit by high-energy electrons becomes one of the most serious heating parts in TWTs, which affects the working life and stability. It is of most importance to find collector materials with high thermal conductivity and low secondary electron yield. A highly oriented graphite/copper composite was prepared by powder metallurgy technology, and the thermal conductivity and secondary electron emission coefficient of the composite with different graphite content were studied. It was found that with the increase of graphite content, the thermal conductivity of the composite could reach maximum value of 733.2 W/（m·K）, while the secondary electron emission coefficient decreased. When the graphite content is 50 vol%, the δ_max is 1.11.更多还原