烧结温度对碳化硅陶瓷力学性能的影响

采用硼、碳助剂无压烧结制备碳化硅陶瓷。针对烧结温度与碳化硅烧结体密度、抗弯强度以及硬度之间的关系进行了试验研究,并对不同温度下制备的烧结体进行了显微结构形貌观察和XRD图谱分析。结果表明,烧结温度在2190～2220℃范围内可以制备密度高、力学性能好的碳化硅陶瓷。其相对密度超过96%;抗弯强度接近400MPa;维氏硬度23GPa以上。在试验温度范围内,密度与抗弯强度之间的关系近似为线性关系,密度越高抗弯强度和硬度性能越好。

Influence of sintering temperature on mechanical properties of silicon carbide ceramics

Pressureless sintering of silicon carbide with C、B as sintering additives were carried out. The influence of sintering temperature on mechanical properties of silicon carbide ceramics was investigated. Microstructure and XRD pattern of the sintered bodies at different sintering temperature were analyzed. The results show that dense SiC ceramics with good mechanical properties are obtained at sintering temperature of 2190～2220℃. It has relative density of more than 96%;bending strength of near 400MPa; Vickers hardness of more than 23GPa. In the testing temperature range, the relation curve between density and bending strength is approximate to linear one. The higher density, the better is the bending strength and the hardness.