炭质原料对C-SiC-B_4C复合材料性能和微观结构的影响

Influence of Carbon Materials on the Properties and Microstructure of C-SiC-B_4C Composite

分别采用鳞片石墨、生石油焦和煅后沥青焦为基体炭质原料,以酚醛树脂作为粘结剂,掺入定量SiC,B4C陶瓷相,通过模压成型(140MPa 1min)制备弥散型C-SiC-B4C复合材料.研究了原料种类及含量对C-SiC-B4C复合材料性能和显微结构的影响.研究表明:C-SiC-B4C复合材料的性能和显微结构与基体炭质原料的种类和含量有关,生焦的微观结构以流线型为主,以生石油焦为原料制备的复合材料抗压强度最高,达到226MPa;煅后沥青焦的显微结构以镶嵌型居多,制备的样品导电性较差,抗氧化能力最弱;以晶态鳞片石墨为原料制备的复合材料显示出了较低的电阻率和较好的抗氧化性能.

C-SiC-B4C composites were prepared by using a mixture of phenolic resin binder, SiC,B4C, flake graphite, green coke and calcined pitch coke as the raw materials for uniaxial compression. The influence of the raw materials on the performance and microstructure of C-SiC-B4C composites was investigated. The result has shown that the C-SiC-B4C composites prepared with raw materials of green coke possess excellent compressive strength, while those prepared with raw materials of flake graphite present the lowest resistivity and the best oxidation resistance.