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以钇铝石榴石(YAG)为助烧剂,利用等离子放电烧结(SPS)制备SiC–TiB_2复相陶瓷。采用X射线衍射、扫描和透射电子显微镜、能量色散X射线能谱对材料物相及微观结构进行了表征。研究了SPS烧结温度及TiB_2的加入对材料微观结构尤其是晶界相形态和力学性能的影响。结果表明:虽然TiB_2的加入对材料致密化起到了一定的阻碍作用,但是促使晶界相从晶态向非晶态转变,提高了晶粒间结合强度,材料的力学性能得到提升。烧结温度为1 750℃制备的SiC–TiB_2陶瓷抗弯强度最高,为753 MPa,烧结温度为1 700℃制备的SiC–TiB_2陶瓷断裂韧性最高,为8.84 MPa·m~(1/2)。
SiC-TiB 2 multiphase ceramics were prepared by plasma discharge sintering (SPS) using yttrium aluminum garnet (YAG) as sintering aid. X-ray diffraction, scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy were used to characterize the material phase and microstructure. The effects of SPS sintering temperature and addition of TiB 2 on the morphology and mechanical properties of the microstructure, especially the grain boundary phase, were investigated. The results show that although the addition of TiB 2 can hinder the material densification, the grain boundary phase changes from the crystalline state to the amorphous state, and the interfacial bonding strength is improved, and the mechanical properties of the material are improved. The highest flexural strength of SiC-TiB 2 ceramics prepared at 1 750 ℃ was 753 MPa, and the highest fracture toughness was 8.84 MPa · m -1 at the sintering temperature of 1 700 ℃.