(西北工业大学 凝固技术国家重点实验室，西安 710072)
摘 要: 采用Gleeble−3500型热模拟试验机对片层组织TA15钛合金进行等温恒应变速率压缩试验，研究其在两相区860~970 ℃和应变速率0.01~1 s−1范围内的热变形行为和组织球化过程。结果表明：片层组织TA15合金两相区变形应力对温度和应变速率很敏感，应力峰值高于等轴组织合金变形时的峰值，而且其前后应力的硬化率和软化率随着温度的降低和应变速率的增大而逐渐增大。应变对片层组织球化的影响最显著，在本实验条件下，片层组织开始球化的临界应变为0.34~0.59，完全球化需要的应变为3.4~6.8。TA15片层组织两相区变形应力的软化主要原因是片层组织球化和弯折。
关键字: TA15钛合金；片层组织；球化；热变形
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The hot deformation behavior and globularization processes of TA15 with lamellar structure were studied in the temperature range of 860−970 ℃ and strain rate range of 0.01−1 s−1 by hot compression tests using Gleeble−3500 thermal simulation testing machine. The results show that deformation stress of TA15 alloy with lamellar structure is sensitive to the temperature and strain rate, and the stress peak is higher than that of alloy with equiaxed structure. Further more, the hardening ratio before stress peak and the softening ratio after stress peak increase with lower temperature and higher strain rate. The strain is the most remarkable factor of hot deformation parameters that affect the globularization process. The critical strain for initiation of globularization is between 0.34 and 0.59, and the strain for full globularization is between 3.4 and 6.8. The globularization and bending of lamellar structure are the main reasons of flow softening.
Key words: TA15 titanium alloy; lamellar structure; globularization; hot deformation
