凝胶-共还原法制备超细Mo-Cu粉末及其烧结性能

Characterization and sintering behavior of ultra-fine Mo-Cu powder prepared by gelatinization-coreduction method

以(NH4)6Mo7O24·4H2O和CuO为前驱体,采用有机物辅助的凝胶工艺制得干凝胶。干凝胶经煅烧、还原后,获得Cu含量为20%(质量分数)的Mo-Cu复合粉末。该Mo-Cu粉末模压成形后,在H2中于1050～1150℃烧结,制得Mo-Cu复合材料。通过X射线衍射,透射电镜等对干凝胶煅烧后产物及其还原后粉体的相组成、形貌和粒度等进行了表征;通过扫描电镜观测了不同温度烧结所得Mo-Cu复合材料烧结体的显微结构,并对其密度、电导率和强度等物理力学性能进行了测定。结果表明:通过凝胶-共还原法可以制备分散均匀、平均粒度为200nm的Mo-Cu超细粉末;该Mo-Cu粉末烧结活性高,其成形压坯在1150℃下于H2气氛中烧结90min后相对密度可达99.65%,且烧结体的晶粒细小均匀,具有良好的物理力学性能。

Mo-Cu composite powders were prepared by gelatinization-coreduction method, in which gels were obtained from precursors of （NH4）6MoTO24·4H2O and CuO powders. The gel was then calcined and H2-reduced to convert into Mo-Cu powders. The phase constitute and morphology of the calcined gel, as well as the Mo-Cu composite powders were characterized by X-ray diffractometry and transmission electron microscopy. Mo-Cu powders were die-pressed and sintered in H2 atmosphere in temperature range of 1 050-1 150 ℃. The physical and mechanical properties of sintered Mo-Cu materials were tested, and the microstructure was observed by scanning electron microscopy. The results show that Mo-Cu composite powders with mean particle size of about 200 nm were obtained by gelatinization-reduction method. The powder exhibits good dispersion of Mo and Cu ingredients and high sinterability. A relative density of 99.65% is achieved for Mo-Cu composites sintered at 1 150 ℃ for 90 rain in H2 atmosphere. Furthermore, the prepared Mo-Cu materials show good physical and mechanical properties.