摘要
以Ｙ２Ｏ３和Ｌａ２Ｏ３为添加剂，利用微波烧结成功地制备出Ｓｉ３Ｎ４陶瓷。在最佳工艺条件下，其抗弯强度和断裂韧度分别为６８０～７２０ＭＰａ和６．８～７．８ＭＰａ·ｍ１／２。研究了烧结工艺对致密化过程和力学性能的影响。实验结果表明，微波烧结能够大大降低烧结温度，促进致密化和α→β相变。为了仰制Ｓｉ３Ｎ４分解，必须采用高Ｎ２压力（＞０．５ＭＰａ）。微波烧结Ｓｉ３Ｎ４的显微结构均匀。
Si 3N 4 ceramics containing Y 2O 3 and La 2O 3 as complex additives are prepared successfully by microwave sintering, its roomtemperature flexural strength and fracture toughness are 680-720MPa and 6.8- 7.8 MPa·m 1/2 at the optimum, processing conditions. The effects of sintering processing on densification procedure and mechanical properties are investigated. The experimental results showed that the microwave sintering can greatly decrease the sintering temperature and promote the densification and the phase transformation of α to β-Si 3N 4. The higher N 2 pressure (>0.5MPa)is necessary to depress the decomposition of Si 3N 4. Microwave sintered Si 3N 4 has homogeneous microstructure and fine grains.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
1998年第2期33-36,55,共5页
Ordnance Material Science and Engineering
关键词
氮化硅
致密化
显微结构
微波烧结
silicon nitride, microwave, densification, microstructure, mechanical properties
