C-SiC-B4C复合材料的制备及其抗氧化性能研究

PREPARATION OF C - SiC - B4C COMPOSITES AND STUDY ON THEIR OXIDATION RESISTANCE

以生石油焦为炭质原料，向其中掺入定量SiC、B4CN瓷相，以改质煤焦油沥青作为粘结剂，通过模压制备出C—SiC—B4C复合材料。通过XRD、SEM、DTA—TG、EDS等分析方法研究了SiC、B4CNJ瓷相对C—SiC—B4C复合材料结构和性能的影响。研究表明，C—SiC—B4C复合材料的高温抗氧化性与氧化温度、各陶瓷相含量、本身气孔率等有关。掺入的Sic、B4C能够在一定程度上降低炭材料的气孔率，同时，高温条件下陶瓷相形成硼硅酸玻璃覆盖炭基体表面，减少材料表面活性区域数量，提高炭材料的表观活化能。

C- SiC- B4C composite materials were prepared from different ratios of ground mixed powders of green petroleum coke, coal tar pitch, SiC, and B4C by eompression moulding. Effects of the structure and performance of sepiolite were investigated by XRD, SEM, DTA- TG, and EDS. The test results show that the oxidation resistance in high temperatures depended closely on the temperature, the proportion of ceramic phase, and porosity. The addition of SiC and B4C, which not only reduce the porosity and surface active area but also improve apparent activation energy as well.