热压烧结TiB2-ZrB2固溶复合陶瓷的结构研究

以ZrB2作为掺加剂，通过热压烧结制备了TiB2-ZrB2固溶复合陶瓷。采用X射线衍射分析对材料的相组成，晶格常数和晶体结构进行了分析，材料的显微结构分别由EPMA，SEM和TEM测定。研究结果表明，随着ZrB2掺入量的增大，固溶产物的晶格常数会相应增加，当ZrB2的掺加量为8％（摩尔分数）时，产物的晶格常数出现极大值；ZrB2可以与TiB2形成部分固溶的固溶体，在复合材料中存在富Ti和富Zr的两种硼化物；由于固溶反应在界面上进行，有效地降低了烧结过程中的晶界移动速度，从而使材料的大晶粒细化。

STUDY ON THE STRUCTURE OF TiB2-ZrB2 COMPOSITES PREPARED BY HOT PRESSING

TiB 2-ZrB 2 solid solution composites were prepared by hot pressing. The effects of additive content on phase constituent and crystal structure of the composite were investigated by X_ray diffraction analysis. The microstructure analysis was carried out by EPMA, SEM and TEM. Under the experimental conditions, it is shown that crystal parameters increase with the increase of ZrB 2 content and reach the maximum value when ZrB 2 content is 8%(in mole). Two types of boride, Ti_rich and Zr_rich compounds, are found in the composite due to ZrB 2 partly dissolving in the TiB 2 matrix at the interface. the velocity of the grain boundary immigration decreases effectively by the solid solution reaction during sintering, which redounds to gain uniform grains in composite.