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以B4C,TiO2和石墨粉为原料,采用原位反应热压烧结工艺(2050℃,35MPa,1h)制备了致密的TiB2含量为10%～40%(体积分数)的TiB2/B4C复合材料,并对复合材料的组织结构和力学性能进行了研究。扫描电子显微镜和透射电子显微镜分析结果表明:在B4C晶内及晶界处均匀分布着纳米或亚微米级的TiB2颗粒,随着TiB2含量的增加,弹性模量和断裂韧性明显增大,而弹性模量和抗弯强度却随之减小。40%(体积分数)TiB2/B4C复合材料具有高的断裂韧性,高达8.2MPam1/2,主要增韧机制由微裂纹增韧和裂纹偏转增韧。
The compact TiB2 / B4C composites with TiB2 content of 10% ~ 40% (volume fraction) were prepared by in situ reactive hot-pressing sintering process (2050 ℃, 35MPa, 1h) using B4C, TiO2 and graphite as raw materials The structure and mechanical properties of the composites were studied. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that TiB2 particles with nanometer or submicron size are uniformly distributed in the B4C grains and at the grain boundaries. With the increase of TiB2 content, the elastic modulus and the fracture toughness obviously increase, while the elasticity Modulus and bending strength are reduced. 40% (volume fraction) TiB2 / B4C composites have high fracture toughness of up to 8.2 MPam1 / 2, the main toughening mechanism toughening by micro-crack toughening and crack deflecting.