反应烧结微米级SiC陶瓷材料的结构与力学性能

选用粒径为7μm的SiC粉体,采用反应烧结工艺制备致密的SiC陶瓷材料,研究了反应烧结SiC陶瓷材料的物相组成、显微组织结构与力学性能及其断口形貌。结果表明:通过优化制备工艺,SiC陶瓷素坯中的SiC颗粒和纳米炭黑粉体分布均匀,且具有三维联通的孔隙结构,有良好的硅熔渗性能。反应烧结SiC陶瓷材料中的SiC含量高,游离硅含量少,密度可达3.01g.cm-3,抗弯强度达到410MPa,洛氏硬度达到95HRA,综合性能达到陶瓷机械密封件的技术要求。

Microstructures and Mechanical Properties of Reaction Sintered Micron Silicon Carbide Ceramics

Choosing 7 μm SiC powder as a raw material, SiC ceramics were prepared via a reaction sintering technique. Phases, microstructures, mechanical properties and fractographs of the SiC ceramics were studied. The results indicated that the micron SiC particles and graphite nano-particles distributed uniformly in the SiC preforms in which 3-dimensional connecting pores were formed, ensuring a fine infiltration ability of the melted Si in the SiC performs. The reaction sintered SiC （RSSC） ceramics had a high SiC content and a low free Si content. The main property values of the RSSC ceramics were the density of 3. 01 g cm a, the Rockwell hardness of 95 HRA and the bending strength of 410 MPa, which completely met the technological requirements of the ceramic machinery seals.