Co包覆纳米Al_2O_3/TiC复合材料的制备及其显微结构研究  

Preparation and microstructure of nano-size cobalt-coated Al_2O_3/TiC composites

作　　者：师瑞霞[1] 尹衍升 李嘉[1] 陈守刚[2] 刘英才[2] 

机构地区：[1]济南大学材料学院,山东济南250022 [2]中国海洋大学材料学院,山东青岛266003

出　　处：《材料热处理学报》2006年第3期1-5,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(50572034);济南大学博士启动基金(B0414)

摘　　要：采用Co包覆Al2O3/TiC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。对综合力学性能最佳的nATC8复合材料进行了工艺参数的优化,得出其优选工艺参数为,烧结温度1650℃,保温30min,热压30MPa。采用优选工艺参数制备的纳米复相陶瓷材料的硬度为92.7HRA,弯曲强度fσ为782MPa,断裂韧性KIC为7.81MPa.m1/2。通过对其断口的观察,发现形成了晶内型结构,并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。Al_2O_3/TiC composites were prepared by hot pressing sintering at different temperatures using mixtures of Co-coated Al_2O_3 and TiC nano-powders with different Co content.The processing parameters of the composites with best comprehensive mechanical properties were optimized.It is concluded that the optimum processing parameters are sintering temperature 1650℃,holding time 30 minutes and hot-pressing pressure 30 MPa,respectively.The hardness,flexure strength and fracture toughness of the nano-size composite prepared by using the best processing parameters are 92.7HRA,782MPa and 7.81MPa·m^(1/2).It is found that intragranular structure is formed,and the tortuous routes of crack propagation and the branching,deflecting and bridging are also observed on the fracture surface.

关 键 词：钴包覆 烧结行为 力学性能 工艺参数 复合材料 

分 类 号：TQ174[化学工程—陶瓷工业]