原位生成CeB_6/B_4C陶瓷的力学性能和显微组织  

The mechanical properties and microstructure of in-situ synthesized CeB_6/B_4C ceramic

作　　者：徐璟玉[1] 吴文远[1] 边雪[1] 涂赣峰[1] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110004

出　　处：《功能材料》2009年第2期278-280,283,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(50574031)

摘　　要：通过B4C、CeO2和C的化学反应,采用原位生成法,在热压烧结的条件下制备了CeB6/B4C陶瓷材料。研究了CeB6/B4C陶瓷材料的力学性能和显微组织,并对其增韧机理进行了分析。结果表明:原位生成的CeB6/B4C陶瓷只有CeB6和B4C两相,其显微维氏硬度、抗弯强度、断裂韧性最大值分别达到40.64GPa、346.7MPa、5.95MPa.m1/2,比纯碳化硼分别提高了52.50%、17.96%、61.68%。原位生成的CeB6颗粒细晶增韧补强,B4C和CeB6颗粒之间热膨胀系数不匹配产生的残余应力导致的裂纹偏转以及沿晶断裂是CeB6/B4C陶瓷的主要增韧机制。CeB6/B4 C ceramics were prepared by hot-pressed sintering based on in-situ synthesis. The mechanical properties and the microstructure of CeB6/B4 C ceramics were studied, and the toughening mechanisms of CeB6/ B4C ceramics were also investigated. The results showed that, the phase composition of CeB6/B4C ceramics were CeB6 and B4C, and the max microhardness, flexure strength and fracture toughness of CeBs/B4C ceramic composites were 40. 64GPa, 346. 7MPa and 5.95MPa·m^1/2 reapectively, which were higher than pure boron carbide by 52.50%,17.96% and 61.68% respectively. The fine grain toughening and reinforcing by CeB6 produced in-situ synthesis, the crack deflection caused by residual stress resulting from the difference in thermal expansion coefficient between B4 C and CeB6 and he transgranular rupture were the main toughening mechanisms of B4C/CeB6 ceramics.

关 键 词：原位生成 CeB6/B4C陶瓷 力学性能 显微组织 增韧机理 

分 类 号：O614.3[理学—无机化学]