Bending strength and crack-healing behavior of Al_2O_3/SiC composites ceramics

摘要

Five kinds of ceramics were used to evaluate the bending strength under three-point bending. The bending test was carried out at room temperature. The crack-healing behavior and the bending strength of the crack-healed specimens were investigated from room temperature to 1723 K. The bending strength of Al_2O_3/SiC composite ceramics is higher than that of Al_2O_3 monolithic. Al_2O_3/SiC composite ceramics could completely heal semicircular cracks with diameters 100 μm. The bending strength of Al_2O_3/SiC composite ceramics significantly increased after heat treatment at 1573 K for 1 h in air. The crack-healing ability of Al_2O_3/SiC composite ceramics was the best in additive powder 3 wt.% Y_2O_3.