Fabrication of Layered Ti_3SiC_2/α-SiAION Material

摘要

Abstract. Ceramic powders with Ti_3SiC_2 content up to 97.5 vol% were reactive synthesized from powders of 3Ti: SiC: C. Bulk ceramic composed of 81.5 vol% Ti_3SiC_2 and 18.5 vol% TiC were densified by hot pressing from the as-synthesized Ti_3SiC_2 powders. The relative density, hardness and strength are 98.70%, 7.2GPa, and 380MPa, respectively. Bulk Ca-a-SiAlON was fabricated through reactive hot pressing from the mixtures of CaCO_3: Si_3N_4: A1N. The density, toughness, and hardness of the hot pressed Ca-α-SiAlON is 99.88%, 5.1 MPa·m~(1/2), and 18.3GPa respectively. Based on the results, green tapes of Ti_3SiC_2 and CaCO_3: Si_3N_4: A1N were prepared by roll forming with binders. Three-layered structure of Ca-α-SiAlON/Ti_3SiC_2/Ca-a-SiAlON was formed by stacking the tapes and densified by hot pressing. It was demonstrated that residual stress between layers, crack deflection and the layered structure of Ti_3SiC_2 grains are the major factors that improve the damage resistance of this kind of laminated material.