原位合成增强体TiB层错的透射电镜分析

TEM Research on Stacking Faults of In situ Synthesized Reinforcement TiB

利用透射电镜和高分辨率透射电镜研究了原位合成钛基复合材料增强体 Ti B的堆垛层错结构 .结果表明 ,堆垛层错容易在 Ti B的 (1 0 0 )面上形成 ,平行于 Ti B的生长方向 [0 1 0 ] ,并贯穿整个增强体 .堆垛层错在 Ti B形核与长大的过程中形成 ,并且与增强体 Ti B的 B2 7晶体结构有关 .由于 Ti B的 B2 7结构 ,在 (1 0 0 )面上容易形成 B原子的不足而导致原子错排 ,并且在 (1 0 0 )面上形成堆垛层错有利于减少增强体与基体合金之间的晶格畸变 .

Stacking faults of in situ synthesized reinforcement TiB in titanium matrix composites were observed by transmission electron microscope (TEM) and high-resolution transmission electron microscope (HREM). Stacking faults are likely to form ont the (100) plane and are parallel to the growth direction [010] of TiB. Moreover, the stacking faults penetrate the reinforcement. The stacking faults form during the nucleation and growth of TiB and are related to B27 structure of TiB. Due to B27 structure, the scarcity of boron atoms is likely to form on the (100) plane which would result in the stacking disfigurement on the (100) plane. Moreover, the formation of stacking faults on the (100) plane serves to minimize the lattice strain between the TiB and the titanium matrix alloy.