Ultra-fine aluminum oxide and tungsten mixed powder and preparation method thereof

The invention discloses ultra-fine Al2O3/W mixed powder and a preparation method thereof. The ultra-fine Al2O3/W mixed powder comprises the following components in percentage by volume: 1 to 60 percent of aluminum oxide and the balance of tungsten and unavoidable impurities. The invention also discloses the preparation method of the mixed powder. The preparation method comprises the following steps of taking aluminum nitrate and ammonium tungstate as raw materials, taking citric acid as a complexant, uniformly mixing the components by a liquid-and-liquid mixing and stirring method, evaporating and drying the mixture to obtain a high polymer which contains aluminum oxide and tungsten oxide, baking the high polymer in air atmosphere to remove organics to obtain mixed power of aluminum oxide and tungsten oxide, and performing two-section hydrogen reduction to prepare ultra-fine powder of Al2O3/W which are uniformly mixed. In the prepared Al2O3/W mixed powder, particles are not gathered into balls, the components are uniform, the granularity of the aluminum oxide is 50 to 90 nanometers, and the granularity of tungsten is 0.5 to 0.8 microns.