碳化硅增强氮化硅陶瓷复合材料的制备与表征

为了增加陶瓷球的韧性和耐磨性,提高轴承的抗冲击能力,在氮化硅中掺杂碳化硅,将硅粉、碳粉按一定比例混合,在氮气环境下采用自蔓延高温合成技术烧结,用热压烧结法制备不同碳含量的复合陶瓷,并通过试验研究其性能。结果表明:在氮化硅基陶瓷中掺杂质量分数为5%的碳化硅能改善晶界,有效抑制陶瓷球疲劳裂纹的扩展,材料韧性提高19. 23%,磨损率降低20. 83%,陶瓷轴承的抗冲击性能大大提高。

Preparation and Characterization of Silicon Nitride Ceramic Composites Reinforced by Silicon Carbide

In order to increase toughness and wear resistance of ceramic balls and improve impact resistance of bearings,the silicon carbide is mixed into silicon nitride,and the silicon powder and carbon powder are mixed with certain proportion.The self-propagating high-temperature synthesis sintering technology is adopted under nitrogen environment,then the composite ceramics with different carbon contents are prepared by hot-pressed sintering method,and the performances are studied by experiments.The results demonstrate that addition of silicon carbide with mass fraction of 5% into silicon nitride ceramics is able to improve grain boundary and inhibit propagation of fatigue cracks of ceramic balls effectively,while the toughness of materials is improved by 19.23% and the wear rate is reduced by 20.83%.The impact resistance of ceramic bearings is improved greatly.