高性能Si3N4基可加工复合陶瓷的快速制备

采用SPS在1600～1650℃烧结5min可以获得致密的Si_3N_4-BN复相陶瓷,实验结果表明,随着BN体积分数的增加,BN聚集生长导致Si_3N_4-BN复相陶瓷强度总体均呈缓慢下降趋势,但仍然维持在很高的强度水平,BN体积分数为30%时三点弯曲强度接近900 MPa,而且拥有优异的可加工性能,SEM分析表明,借助SPS可以在实现Si_3N_4-BN复相陶瓷快速致密化基础上进行相组成及显微组织的调控和优化,从而改善材料的性能。

Rapid Preparation of Strong Machinable Si3N4-based Composites

Dense Si_3N_4/BN composite ceramics were fabricated by SPS at 1600～1650℃for 5 minutes.Ex- perimental results indicate the SPSed Si_3N_4/BN composite ceramics maintains a considerably high bending strength,though it has a gradual decrease with increasing BN,caused by the aggregation of h-BN grains. The bending strength of sample was nearly 900 MPa when BN content got up to 30%,which could be highly machined by WC tool as well.SEM analysis suggests that microstructures of the materials are optimized dur- ing SPS process,which play a key role in the improvement of strength.