The starting powder, codeposited Al//2O//3-ZrO//2, consisted of ultrafine spherical delta -Al//2O//3 particles containing tetragonal ZrO//2 crystallites. The phase change of Al//2O//3 from delta to alpha via theta caused accelerated densification at low temperatures (1100-1200 degree C). The addition of ZrO//2 retarded the phase change but excessive ZrO//2 (30 wt%) further hindered densification. The ZrO//2 particles controlled grain growth at 1500-1600 degree C, excessive grain growth occurred. Grain growth is controlled by surface diffusion of the matrix ions around ZrO//2 particles.
|Number of pages||11|
|Journal||Report of the Research Laboratory of Engineering Materials Tokyo|
|Publication status||Published - 1985 Jan 1|
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