Abstract:
The morphology of the Al
2O
3 powder milled by sanding process and the composition, microstructure, and mechanical properties of 95Al
2O
3 ceramics prepared by sintering the powder with SiO
2-ZrO
2-MgO-CaO sintering aid were studied, and compared with those milled by planetary ball. The results show that the average particle size of Al
2O
3 powder after sanding was 0.2 μm, indicating that sanding had a significant refining effect on powder; the median particle size after planetary ball milling was 2.4 μm, which was similar to that of powder without milling. The phases of the ceramics prepared by sintering powder with sanding were Al
2O
3, Al
0.52Zr
0.48O
1.74 and m-ZrO
2, and those prepared by sintering powder with planetary ball milling and without milling were Al
2O
3 and a small amount of m-ZrO
2. The Al
2O
3 grains on surface of the ceramics prepared by sintering powder with sanding did not grow abnormally, and the ZrO
2 phase was pinned at Al
2O
3 grain boundaries; the Al
2O
3 grains prepared by sintering powder with planetary ball milling and without milling grew abnormally. The fracture toughness of ceramics prepared by sintering powder with sanding was (4.6±0.6) MPa·m
1/2, and was higher than those prepared by sintering powder with planetary ball milling and without milling.