Study on the preparation of ALON powder by solid state reaction method

Pure phase ALON (Al23O27N5) ceramic powder was fabricated by using nano-sized Al2O3 and micro-sized or nano-sized AlN powder with different ratios as raw materials and the following process, ball-milling, drying, high temperature calcining, screening, grinding and so on. Several kinds of powder obtained by different molar ratios and sintering conditions were measured by XRD analysis. Then the affecting factors of the powders' phase composition, such as the grain size and molar ratio of the raw materials, the calcining condition and the oxidation behavior of AlN at high temperature in nitrogen atmosphere were studied. The optimal ratio of raw materials and calcining condition for preparing pure phase ALON powder were determined. In addition, the grain size of pure phase ALON before and after ball-milled was measured by TEM analysis, and the specific surface area of the ball-milled ALON powder was measured by BET method.