CAJ | 학술논문

在温度850~930°C、应变速率0.01~1 s-1的条件下，对初始组织为等轴组织的Ti6Al4V钛合金进行变形程度为70%的热压缩变形实验，研究合金的变形组织及织构。结果表明，当温度低于900°C、应变速率高于0.1 s-1时，合金的组织主要是拉长的α晶粒；而在高于900°C以及低应变速率下，则会发生动态再结晶。电子背散射衍射(EBSD)结果显示，合金在再结晶过程中亚晶界吸收位错，最终形成大角晶界。在930°C时动态再结晶已基本完成，水冷至室温时形成针状α相。与原始组织相比，合金在930°C变形时织构得到增强，低于930°C变形时织构变弱。
재온도850~930°C、응변속솔0.01~1 s-1적조건하，대초시조직위등축조직적Ti6Al4V태합금진행변형정도위70%적열압축변형실험，연구합금적변형조직급직구。결과표명，당온도저우900°C、응변속솔고우0.1 s-1시，합금적조직주요시랍장적α정립；이재고우900°C이급저응변속솔하，칙회발생동태재결정。전자배산사연사(EBSD)결과현시，합금재재결정과정중아정계흡수위착，최종형성대각정계。재930°C시동태재결정이기본완성，수랭지실온시형성침상α상。여원시조직상비，합금재930°C변형시직구득도증강，저우930°C변형시직구변약。
Microstructure and texture evolution during hot compression of Ti6Al4V alloy with an initial equiaxed microstructure were studied in the temperature range of 850-930 °C, strain rate range of 0.01-1 s-1 and engineering compressive strain of 70%. The results indicate that when temperature is below 900 °C and strain rate is higher than 0.1 s-1, the microstructure is mainly composed of elongatedα grains. While deforming at higher temperatures and lower strain rates, dynamic recrystallization takes place. Electron back scattered diffraction (EBSD) result shows that during dynamic recrystallization, subgrain boundaries absorb dislocations and the recrystallized grains with high angle grain boundary form. At 930 °C dynamic recrystallization has basically completed, and needlelikeα phase forms after water quenching. Pole figure analysis indicates that compared with the initial specimen, textures below 930 °C are weaker, while at 930 °C they are stronger.