TiB_2/ZrO_2复合材料介电及力学性能研究  

Dielectric and mechanical properties of TiB_2/ZrO_2 composites

作　　者：李鹏[1] 周万城[1] 李坊森[1] 罗发[1] 朱冬梅[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《功能材料》2008年第8期1348-1351,共4页Journal of Functional Materials

基　　金：国家自然科学基金(50572090)

摘　　要：以热压烧结制备了TiB_2/ZrO_2复合材料,研究了其在8.2～12.4GHz的介电特性和力学性能,探讨了材料极化和损耗机理。结果表明,TiB_2降低了复合材料的烧结性能;纯ZrO_2无明显损耗,ZrO_2内部价电子随电场移动使基体发生极化,TiB_2在材料中形成的导电网络使复合材料复介电常数实部和损耗增加。复合材料的硬度随TiB_2体积分数增加而下降,抗弯强度和断裂韧性随TiB_2体积分数增加先上升后下降,这是由复合材料相对密度、基体晶粒尺寸以及TiB_2的韧化作用等因素共同决定的。TiB2/ZrO2 composites were prepared by hot-pressed sintering method, the dielectric performance between 8.2 and 12.4GHz and mechanical properties of the composites were studied, the mechanism of polarization and loss were discussed. The result show that TiB2 deteriorate the sintering character of the composites; Dielectric loss can not be detected obviously in ZrO2 matrix, and vibrations of the valence electrons in ZrO2 are responsible for polarization in the matrix. TiB2 local networks increase the real part of dielectric constant and loss. Hardness of the composites decreases with the volume fraction rise of TiB2. Flexural strength and fracture toughness of the composite increase firstly and then decrease with the volume fraction rise of TiB2, which is caused both by relative density, grain size of the matrix and the toughening effect of TiB2.

关 键 词：TiB2/ZrO2复合材料 介电 力学 机理 

分 类 号：TQ174.75[化学工程—陶瓷工业]