Microstructures and properties of rapidly solidified Y2O3 doped Al2O3/ZrO2 composites prepared by combustion synthesis

Y2O3 doped Al2O3/ZrO2 composites mainly composed of randomly-oriented rod-shaped eutectic grains are prepared by combustion synthesis; within the rod-shaped grains, t-ZrO2 aligned nano-micron fibers are embedded. The increase of the hardness or strength of the ceramics could be attributed to nano-submicron inter-phase spacing and the refinement of the eutectic grains, whereas high-energy, high-angle boundaries between rod-shaped grains could also introduce strong toughening mechanisms involving crack-bridging and pull-out of rod-shaped grains, crack-bridging and frictionally interlocked effects of α-Al2O3 platelet grains.