中文摘要：

采用溶胶凝胶法、共沸蒸馏法和水热合成法制备了Al2O3掺杂W粉末,并经煅烧以及两段氢气还原过程制成W-Al2O3复合粉末。通过SEM形貌观察以及XRD物相分析可知,由3种方法制备的Al2O3掺杂W粉末经过煅烧均得到了稳态单斜相WO3和非稳态六方相WO3;其中水热合成法制得粉末形貌较为规则,为均匀的小球状;经过一段氢气还原,WO3被还原为低价态的WO2和不饱和价态的WO3-x;二段氢气还原后得到了细小的W-Al2O3复合粉末。采用溶胶凝胶法制备的W-Al2O3复合粉末,由于Al2O3包裹在W颗粒表面阻碍了后续被还原W原子的沉积,相较于其他两种方法细化作用更加明显,颗粒可达纳米级。

英文摘要：

Al2 O3-doped W powder was prepared by sol-gel, azeotropic distillation and hydrothermal synthesis to produce W-Al2 O3 composite powder by calcination and two-step H2 reduction. Based on XRD analysis and SEM observation, stable monoclinic WOa and metastable hexagonal WO3 were obtained by calcination of Al2 O3-doped W powder prepared with the above-mentioned three methods. The morphology of the powder prepared by hydrothermal synthesis is regular, uniform and spherical. WO3 is reduced to low-valence WO2 and unsaturated-valence WO3-x by the primary H2 reduction,and fine W-Al2 O3 composite powder is obtained by the secondary H2 reduction. Compared with the other two methods, sol-gel method has more obvious refinement effect and it can prepare W-Al2O3 composite powder with nanoscale particle size, since Al2 O3 coated on the surfaces of W particles inhibits the deposition of tungsten atom during subsequent reduction.