作　　者： ; ; ; ; ;

机构地区： 北方民族大学材料科学与工程学院

出　　处： 《宁夏大学学报（自然科学版）》 2012年第3期254-257,共4页

摘　　要： 采用AlN-稀土氧化物系统烧结助剂,通过液相烧结制备了碳化硅陶瓷.研究了不同稀土氧化物对烧结行为、烧结体显微结构和力学性能的影响.结果表明:Nd2O3-AlN,La2O3-AlN系统烧结失重较大,无法达到完全致密.Y2O3-AlN或AlN-Nd2O3-Y2O3,AlN-La2O3-Y2O3系统可以在较低的温度下实现致密化;所有样品的晶粒细小,尺寸为1～2μm,无异常长大现象;在烧结体中除有高温烧结液相之外,还形成了稀土硅铝酸盐新相;致密的碳化硅陶瓷烧结体不但具有高硬度,而且断裂韧性高达6～8MPa.m1/2. Abstract： Silicon carbide is sintered via liquid phase sintering using A1N-Re203 as sintering additive. The effect of different rare earth oxides on sintering behavior, microstructure and mechanical properties of sintered samples is studied. The results show that in the case of AIN-Nd2O3, AIN-La2O3 as sintering aids, the weight loss reach more than 5% and fully densification is impossible. When either A1N-Y2O3 or A1N- Nd2O3-Y2O3, AIN-La2O3-Y2O3 is used as sintering aids, fully densification of SiC can be obtained at relatively low temperature. Microstructure analysis show that grains are predominantly equiaxed with a mean grain size of 1-2 Fm, relatively little grain growth occurred during densification. XRD results reveal that rare-earth silicon oxynitrides new phase formed in the sinteron sample . The dense sample owns high toughness of 6-8 MPa · m1/2 , with high hardness.

关 键 词： 碳化硅 稀土氧化物 稀土硅铝酸盐

领　　域： [化学工程] [化学工程]