【摘要】 以MoO3为原料配置悬浮料浆,采用喷雾干燥-氢气还原工艺制备钼粉,并以Mo预烧坯为骨架,采用熔渗法制备Mo-15Cu复合材料。借助X射线衍射和扫描电镜分别分析Mo粉物相组成和颗粒形貌;通过分析粉末的压缩特性,确定预烧骨架密度变化、径向收缩率以及熔渗样理论密度变化;借助金相显微镜观察熔渗样金相组织,借助热导仪和热膨胀分析仪测定合金的热性能。结果表明:所制备的钼粉纯度高、球形度高、压缩性好。在压制压力720 MPa、预烧温度1 250℃时,钼骨架中钼的体积分数为83.2%,Mo-15Cu复合材料的致密度为99.6%,热导率153 W/(m-K),线膨胀系数为7.0×10-6/K。熔渗样中存在极少孔隙,钼颗粒细小,钼与铜两相分布均匀。更多还原

【Abstract】 Molybdenum powders were fabricated by MoO3 via spraying drying-hydrogen reduction method,and Mo-15Cu composite was prepared by infiltration method using Mo pre-sintered compact as skeleton,and then Mo-15Cu composite’s phase composition and particle morphology were examinated via X-ray diffraction(XRD) and scanning electron microscopy(SEM) respectively.Besides,Mo-15Cu alloys properties were studied through observing metallographic microstructure of infiltration sample,measuring the compactibility of molybdenum powders,relative density and radial dimension of Mo skeleton,and relative theoretical density of infiltration sample.The results show that as-prepared molybdenum powders have high purity,high degree of sphericity and excellent compactibility.When the pressure is 720 MPa and the pre-sintering temperature is 1250 ℃,relative volume fraction of Mo in pre-sintering molybdenum skeleton is 83.2% and the alloy relative density achieves to 99.5%.The thermal conductivity and thermal expansion coefficient are 153 W/(m?K) and 7.0×10-6 K-1 respectively.Metallographic mico-structure of infiltration sample shows that it scarcely has porosity,molybdenum particles are fine,and the phases of copper and molybdenum are homogeneous.更多还原