摘 要：以两面顶为成型设备，利用其超高压力（4.5 GPa）来提高素坯 的相对致密度，从而降低坯体的烧结温度、缩短烧结时间，并制备出高 致密度的细晶碳化硅陶瓷。结果表明，经超高压成型后，碳化硅素坯的 平均相对致密度为 65.7%。 与冷等静压成型后的坯体（45.5%）相比，提 高了大约 20%。 在低压流动氮气保护下，超高压成型的坯体于 1 900 ℃下无压烧结 30 min，烧结体的致密度达到了 98.3%，其晶粒尺寸在 200 nm 左右。 

关键词：碳化硅；超高压成型；无压烧结；微观结构

Abstract: Two-face press was used as the compacting equipment in this paper. With its ultra-high pressure (4.5 GPa)，the two-face press could be used to improve the relative density of SiC green bodies. The high density green body would help to prepare the high density， fine crystalline SiC ceramics with lower sintering temperature and shorter sintering time. The results showed that after ultra-high pressure compaction， the average rel ative density of SiC green body was high to 65.7%. By comparing to the green body after cold isostatic pressing (45.5%)， it increased about 20%. SiC green body after ultra-high pressure compaction was pressureless sin tered at 1 900 ℃， 60 kPa N2 for 0.5 h， the density of the sintered body was high to 98.3%， and the average grain size was about 200 nm. 

Keywords: silicon carbide; ultrahigh pressure compaction; pressureless sintering; microstructure