原位生成硼化钨对CuW合金组织与性能的影响

Effects of In-situ Synthesis of Tungsten Boride on Microstructures and Properties of CuW Alloy

用粉末冶金-烧结熔渗法制备了不同B添加量的CuW合金。研究了B添加量对CuW合金组织、静态性能、真空电击穿性能以及耐磨性的影响。结果表明,B元素在W骨架烧结过程中原位生成了硼化钨,强化了W骨架,在B质量分数为0.6%时,使CuW合金的HB硬度提高到2150MPa。同时W2B相的原位生成,提高了CuW合金的电击穿强度和耐磨性。使添加0.6%B的CuW合金的耐电压强度提高57.5%,截流值降低21%,摩擦系数降低了32.7%。对真空电击穿后的表面烧蚀形貌分析发现,添加B元素的CuW合金击穿坑分散且较小,铜液的集中飞溅现象减轻。

A series of Cu-W alloys added with different boron contents were prepared by means of powder metallurgy-infiltration process. The effects of boron addition content on the microstructure and properties of CuW alloys were investigated. The static properties, the vacuum breakdown property and the wear resistance were studied, respectively. The results show that boron element and W in-situ react and form tungsten boride phase in the sintering process of W skeletons. The HB hardness of the CuW-0.6 wt%B alloy increases to 2150 MPa owing to strengthen of W skeletons. Meanwhile, the breakdown strength increases by 57.5%, the chopping current decreases by 21%, and the coefficients of friction decreases by 32.7%, respectively. The breakdown strength and wear resistance of the CuW alloys are enhanced significantly. The morphologies analysis of CuW alloys after vacuum breakdown shows that the splash of liquid copper decreases, the breakdown areas increase but the erosion pits become shallower and smaller.