纸制备SiC/Si层状陶瓷复合材料的微观结构和性能

THE MICROSTRUCTURE AND THE PROPERTY OF SiC/Si LAMINATED CERAMIC COMPOSITES FROM PAPER

本文以纸为原料,通过叠层设计、低温碳化和高温渗硅制备了具有层状结构特征的SiC/Si陶瓷复合材料。并采用XRD、SEM和三点弯曲等分析测试手段对其相组成、微观结构和力学性能进行了分析。结果表明:纸碳化后为非晶形的碳;渗硅后试样的相组成为β-SiC相、自由Si相和残C相。叠层纸碳化后的微观结构为含有大量扁长空洞的碳骨架,渗硅后得到的SiC陶瓷复合材料具有明显的层状结构特征。三点弯曲实验表明,SiC/Si陶瓷复合材料的强度高达290MPa,达到了常规反应烧结SiC陶瓷的强度水平;且其断裂方式为非灾难性断裂,分析认为这与材料的层状结构形貌有关。

In this paper, SiC/Si laminated ceramic composites were fabricated using a conventional paper as raw material,first paper was designed with laminate structure, then laminated, finally carbonized at low temperature, in-situ reacted with melt silicon at high temperature in Ar atmosphere. The phase formation and the microstructure were analyzed by XRD and TEM. XRD analysis indicated that carbonized specimen was composed of amorphous carbon, the final product was composed of β-SiC, silicon and residual carbon. SEM showed that carbonized specimen contained many holes and possessed a distinguishable laminated structure. SiC/Si ceramic composites have laminated structure. The strength of SiC/Si ceramic composites which was measured by three-point bending test, was 290MPa, which attained the strength value of the ordinary reaction-bonded SiC ceramics. The laminated SiC/Si ceramic composites showed a non-catastrophic fracture behavior, which attributed to the laminated morphology.