【摘要】 本文通过采用热等静压（ＨＩＰ）这一先进的烧结工艺，研究了Ａｌ２Ｏ３添加量对ＳｉＣ陶瓷之显微结构与力学性能的影响，并成功地制备出Ｓｉ３Ｎ４粒子以及ＳｉＣ晶须补强的ＳｉＣ基复合材料．结果表明：Ａｌ２Ｏ３是ＨＩＰ烧结ＳｉＣ陶瓷及其复合材料的有效添加剂．当添加３ｗｔ％Ａｌ２Ｏ３时，采用ＨＩＰ烧结工艺在１８５０℃温度和２００ＭＰａ压力下烧结１ｈ就可获得密度分别高达９７．３％、９９．４％和９７．０％的ＳｉＣ单相陶瓷、ＳｉＣ－２５ｖｏｌ％Ｓｉ３Ｎ４复相陶瓷以及５ｖｏｌ％ＳｉＣ晶须补强的ＳｉＣ基复合材料．对于ＳｉＣ－２５ｖｏｌ％Ｓｉ３Ｎ４复相陶瓷，其室温强度高达６２５ＭＰａ；对于５ｖｏｌ％ＳｉＣ晶须补强的ＳｉＣ基复合材料，其断裂韧性达到６．７ＭＰａ·ｍ（１／２）．更多还原

【Abstract】 The effects of Al2O3 content on the microstructure and mechanical properties of SiC ceramics were investigated, and Si3N4 particle-and SiC whisker-reinforced SiC based composites were successfully fabricated by hot isostatic pressing. Al2O3 was confirmed to be an effective additive for hot isostatic pressing of SiC ceramics and SiC based composites. When 3wt% Al2O3 was used as the sintering additive, relative densities of 97.3, 99.4 and 97.0% were obtained for SiC monolithic ceramics, SiC-25vol%Si3N4 multiphase ceramics and 5vol% SiC whisker-reinforced SiC matrix composites by hot isostatic pressing under 200MPa at 1850℃ for 1h. The flexural strength and fracture toughness of SiC ceramics were increased by the adition of Si3N4 particles and SiC whiskers. 25vol% Si3N4 particle-reinforced SiC composites had a flexural strength of 625 MPa, and 5vol% SiC whisker-reinforced SiC composites exhibited a fracture toughness of 6.7MPam(1/2).更多还原