Co包覆Al2O3/TiC复合材料的烧结及性能  

Sintering and Properties of Cobalt-coated Al_2O_3/TiC Composits

作　　者：师瑞霞[1] 尹衍升 李嘉[2] 

机构地区：[1]中国海洋大学材料科学与工程研究院,青岛266100 [2]济南大学材料学院,济南250022

出　　处：《人工晶体学报》2008年第3期753-758,共6页Journal of Synthetic Crystals

基　　金：山东省优秀中青年科学家科研奖励基金(No.2006BS04037);国家自然科学基金(No.50572034);济南大学校级重点项目(Y0602)

摘　　要：采用Co包覆Al2O3/TiC微米级、纳米级粉料进行了不同Co含量、不同烧结温度的热压烧结实验。综合分析和对比了两种不同粒径包覆粉体的烧结结果,结果发现纳米级的粉体烧结效果优于微米级粉体的烧结效果。综合力学性能最佳的纳米级复相陶瓷材料的硬度为HRA92.7,抗弯强度σf为782MPa,断裂韧性KIC为7.81MPa.M1/2。利用SEM观察采取综合力学性能最佳的ATC纳米复合材料制备工艺制备的Al2O3、Al2O3/TiC和ATC的断口,可以看出Al2O3、Al2O3/TiC主要以沿晶断裂为主,而ATC为沿晶与穿晶混合断口,并从ATC断口,发现形成了晶内型结构,观察到了裂纹曲折的扩展路径以及裂纹的分叉、偏转、桥联这些有助于材料强度和韧性提高的现象。The hot-pressing sintering studies were carried out by using mixtures of cobalt coated Al2O3 and TiC micro-size and nano-size powders with different cobalt content at different temperatures.The results show that the sintering effects of nano-size powders is super than micro-size powders.The hardness（HRA）,flexure strength and fracture toughness of the composites measured are 92.7,782 MPa and 7.81 MPa·m^1/2.Compared the fracture surfaces of three materials prepared by the same technology,the fracture modes of Al2O3 and Al2O3/TiC are intergranular mainly.Thus the fracture surfaces of cobalt coated Al2O3/TiC composites（ATC）is the mixture of intergranular and transgranular.Some phenomenon helpful for improving flexure strength fracture toughness such as intergranular-type structure,the tortuous routes of crack propagation,the crack branching,crack deflecting and bridging are observed on the ATC fracture surface.

关 键 词：烧结行为 力学性能 Co包覆 氧化铝 

分 类 号：O78[理学—晶体学]