溶胶凝胶/高温氢还原法制备纳米Mo-ZrO_(2)(Y_(2)O_(3))复合粉末  

Preparation of Nanometer Mo-ZrO(YO) Composite Powder by Sol-gel and High Temperature Hydrogen Reduction

作　　者：康蓉 颜建辉 李茂键[1] Kang Rong;Yan Jianhui;Li Maojian(College of Materials Science and Technology,Hunan University ofScience and Technology,Xiangtan 411201,China;Hunan Provincial Key Defense Laboratory of High Temperature Wear Resisting Materials and Preparation Technology,Hunan University of Science and Technology,Xiangtan 411201,China;Hunan Provincial Key Laboratory of Advanced Materialsfor New Energy Storage and Conversion,Hunan University of Science and Technology,Xiangtan411201,China)

机构地区：[1]湖南科技大学材料科学与工程学院,湖南湘潭411201 [2]湖南科技大学高温耐磨材料及制备技术湖南省国防科技重点实验室,湖南湘潭411201 [3]湖南科技大学新能源储存与转换新进材料湖南省重点实验室,湖南湘潭411201

出　　处：《稀有金属》2021年第3期288-296,共9页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51475161);湖南省自然科学基金项目(2020JJ4025);湖南省研究生科研创新项目(CX20190837)资助。

摘　　要：纳米Mo-ZrO_(2)(Y_(2)O_(3))复合粉末是一种很有发展前景的粉末冶金材料。采用溶胶凝胶法制备前驱体复合粉末,并对得到的前驱体复合粉末采用高温氢还原工艺制备Mo-ZrO_(2)(Y_(2)O_(3))复合粉末。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和能谱分析(EDS)等分析检测技术对前驱体复合粉末的物相组成和微观结构进行表征,并分析不同的还原时间和温度对高温氢还原后Mo-ZrO_(2)(Y_(2)O_(3))复合粉末的物相组成及微观组织结构的影响。结果表明,在400-650℃下煅烧后的前驱体粉末物相均由MoO3组成;随着煅烧温度的升高,粉末形貌按照薄片状-片层状-长棒状规律演变;在保温3 h条件下,MoO3还原成Mo的起始温度为550℃;如果采用一步还原的方法,煅烧产物MoO3完全转换为Mo的还原温度必须高于650℃;溶胶凝胶结合高温氢还原能够制备纳米级别且纯度较高的Mo-ZrO_(2)(Y_(2)O_(3))复合粉末,团聚的复合粉末由80-100 nm细小颗粒组成,ZrO_(2)(Y_(2)O_(3))均匀地分布在Mo基体粉末中。Molybdenum and its alloys had a low coefficient of thermal expansion,superior electrical and thermal conductivities,good high-temperature strength and creep resistance,and excellent high-temperature dimensional stability. Therefore,as high-temperature components,molybdenum and its alloys were widely used in aerospace,electronic communications,electrical equipment,space vehicles and other high-temperature parts. However,to some extent,the low recrystallization temperature(about 1000 ℃),inherent brittleness and insufficient strength hindered their practical application. It was well known that ultrafine grained or nanocrystalline materials have better mechanical properties than that of the conventional coarse-grained materials. Therefore,preparing ultrafine grained or nanocrystalline composite materials was an effective way to enhance the mechanical properties. Moreover,Y_(2)O_(3) partially stabilized ZrO_(2) had a great potential in improving the comprehensive mechanical properties of molybdenum and its alloys. However,the study had not yet reported the preparation of the Mo-ZrO_(2)(Y_(2)O_(3))nanometer composite powders. The nanometer Mo-ZrO_(2)(Y_(2)O_(3))powders were prepared by sol-gel and high temperature hydrogen reduction,the details were as follows:Firstly,the raw materials of Zr(NO3)4·5H2O,Y(NO3)3·6 H2O and C6H8O7·H2O were dissolved in the distilled water according to a certain proportion and continuously heated with thermostat water bath cauldron at 85 ℃ to form wet gel. Secondly,the wet gel was dried at 110 ℃ for 10 h to obtain the dry precursor powder,and the powder subsequently calcinated at 400~650 ℃ for 5 h in a muffle furnace. At last,the effects of different reduction time and temperatures on the phase composition and microstructure of the Mo-ZrO_(2)(Y_(2)O_(3))composite powders after high temperature hydrogen reduction were also analyzed. The reduction parameters were discussed as follows:(1)reduction time:the powders were reduced at 550 ℃ for 1~5 h in H2 atmosphere;(2)reduction tempe

关 键 词：Mo-ZrO_(2)(Y_(2)O_(3)) 纳米粉末 溶胶凝胶 高温还原 

分 类 号：TQ174.75[化学工程—陶瓷工业]