放电等离子烧结制备碳化硅块材及其高温导热性能研究

通过放电等离子烧结制备了碳化硅块材,分析了烧结温度、保温时间等对碳化硅块材的密度、物相组成、微观形貌和硬度的影响,并对其高温导热性能进行了测试.结果表明,当烧结温度为1800℃,保温时间为5min时,通过放电等离子烧结能够获得致密度为98%的碳化硅块材.与传统热压烧结相比,放电等离子烧结制备的碳化硅块材的热导率略低,其主要原因是放电等离子烧结的保温时间较短与烧结样品的致密度略低,且晶界结合性较差所导致.

Fabrication of Si C Bulk Materials by Spark Plasma Sintering and Its High Temperature Thermal Conductivity Properties

Si C bulk materials were prepared by spark plasma sintering( SPS). The influence of the sintering temperature and the holding time on the density,phase composition,microstructure and hardness were studied. High temperature thermal conductivity was also tested and analyzed. Experimental results show that SiC bulk materials with a relative density of 98% can be fabricated by SPS with a sintering temperature at 1 800 ℃ for 5 min. Moreover,thermal conductivity a of SiC bulk materials prepared by SPS is slightly lower than that prepared by traditional hot-pressing sintering. The main reason can be ascribed to the short holding time of SPS,which leads to the lower density than that of hot-pressing samples,as well as poor grain boundary bonding.