Large-Bulk Solidified Al2O3-ZrO2(Y2O3) Prepared by Self-Pressure Assisting Combustion Synthesis under High Gravity
By introducing self-pressure processing into combustion synthesis under high gravity, Al2O3-ZrO2(4Y) eutectic composite ceramics without shrinkage cavities and holes were achieved, and the self-pressure processing also made the macro-crack be controlled and the ceramic densification be promoted evidently. XRD results showed the eutectic ceramics were composed of α-Al2O3, t-ZrO2 and a few m-ZrO2 phases, and the volume fraction of the transformable t-ZrO2 increased with self-pressure force increasing. SEM images showed that with increasing self-pressure force, the rod-shaped eutectic colonies were refined and the volume fraction of the colonies increased. Meanwhile, the irregular ZrO2 crystals around eutectic colonies transformed to be fine t-ZrO2 spherical crystals gradually, and thickness of eutectic colonies decreased. With the changes in microstructures of the ceramics, the mechanical properties of the ceramics were improved greatly.
Yiwang Bao, Li Tian and Jianghong Gong
G. L. Su et al., "Large-Bulk Solidified Al2O3-ZrO2(Y2O3) Prepared by Self-Pressure Assisting Combustion Synthesis under High Gravity", Advanced Materials Research, Vol. 177, pp. 394-397, 2011