Microstructures and Properties of Al2O3/ZrO2 Composite Ceramics from In Situ Growth in the Melts Produced by Combustion Synthesis
By introducing ZrO2 (3Y) micron powder into the thermit, Al2O3/18%, 21%, 24%, 27% and 30%ZrO2 composite ceramics were obtained from in-situ growth in the melts produced by combustion synthesis. As the volume fraction of ZrO2 is below 27%, the ceramics is comprised of lath-shaped and rod-shaped α-Al2O3 matrix, within the rod-shaped grain the nano-micron fibers are oriented in essentially the same direction. As volume fraction of ZrO2 is over 27%, the ceramics is mainly composed of lamina-shaped grains with alternating α-Al2O3 and t-ZrO2 layers. The flexural strength and the fracture toughness measured simultaneously the maximum values with increasing volume fraction of ZrO2 to 24%, indicating that flexural strength and fracture toughness are simultaneously under the control of rod-shaped grains in which ZrO2 nano-micron monocrystal fibers are embedded.
Wei Pan and Jianghong Gong
Z. M. Zhao et al., "Microstructures and Properties of Al2O3/ZrO2 Composite Ceramics from In Situ Growth in the Melts Produced by Combustion Synthesis", Key Engineering Materials, Vols. 336-338, pp. 2260-2263, 2007