碳源对反应烧结B_4C/SiC复合陶瓷的影响

Effect of Carbon Source on the Reaction Sintering B_4C/SiC Composite Ceramic

本文以酚醛树脂和碳黑为碳源,在碳总加入量一定的情况下,研究了酚醛树脂和碳黑添加比例对反应烧结B_4C/SiC复合陶瓷性能及物相组成的影响。结果表明:在酚醛树脂/碳黑比例在1:8-5:4范围内,比例较小时,B_4C/SiC复合陶瓷试样中游离硅含量较高,力学性能较差;当酚醛树脂/碳黑比例为4:5时,试样致密,综合性能最佳,体积密度为2.75 g/cm^3,维氏硬度、弯曲强度和断裂韧性分别达到30.96 GPa,424 MPa、5.58 MPa·m^(1/2);试样的主晶相为SiC、B_4C和Si,并且Si均匀分布在B_4C和SiC形成的连续相中。

In this paper, recation sintered B4C/SiC composite ceramics were fabricated taking phenolic resin and carbon black as carbonsources, and the effects of phenolic resin and carbon black addition ratio on the properties and phase composition were studied. The resultsshow that, in the phenolic resin/carbon black ratio range of 1：8-5：4, B4C/SiC composite ceramics have high free silicon content and poormechanical properties at a relatively low phenolic resin / carbon black ratio. When the phenolic resin/carbon black is 4：5, the vickers hardness,flexural strength and fracture toughness were 30.96 GPa, 424 MPa, 5.58 MPam/2, respectively. The samples were sufficiently dense andthe comprehensive performance was the best, and the bulk density was 2.75 g/cm3. The main crystal phases are SiC, B4C and Si, and Si isuniformly distributed in the continuous phase formed by B4C and SiC.