SiC基可加工陶瓷材料的强化研究

Improvement of Strength for Machinable Si C-based Ceramic Composites

采用常压烧结在1 700℃下制备出质量分数范围为0～40%的SiC/C（石墨）复相陶瓷材料,对烧结的基体进行浸渗和二次烧结处理,测试了浸渗/二次烧结前后的力学性能、物相组成,并观察了显微结构,对比浸渗和二次烧结等工艺对材料性能的影响。结果表明：浸渗/二次烧结处理能大大降低复合材料的气孔率,提高其强度和硬度。1 700℃烧结后,20%石墨质量分数的SiC/C复合材料试样经过浸渗处理,显气孔率约从32%降低到25%,抗弯强度从46 MPa提高到89 MPa,复合材料的维氏硬度从285 MPa增加到470 MPa。

SiC/C（Graphite） ceramic composites with 0~40% content for weak phase were sintered at 1 700 ℃ by pressureless sintering. Then the sintered samples were dipped and heat-treated. The mechanical properties, microstructures and phases of samples before dipped infiltration and after heat-treating are compared. The results show that the dipped infiltration and heated treat can greatly reduce the porosity of composite materials, improve the flexural strength and hardness. After the dipped infiltration and heated treat, the porosity of SiC/20%C sintered at 1 700 ℃ reduces from 32% to 25%,the flexural strength increases from 46 MPa to 89 MPa and the Hv increases from 285 MPa to 470 MPa.