采用等温压缩试验研究不同原始组织对Ti?5Al?2Sn?2Zr?4Mo?4Cr合金流动应力、应变速率敏感性指数、应变硬化指数和表观变形激活能的影响。结果表明：原始组织为片层组织的Ti?5Al?2Sn?2Zr?4Mo?4Cr合金具有更高的峰值应力和流动软化效应，当变形温度高于或等于810°C、应变速率为0.1~5.0 s?1时，原始组织为等轴组织的Ti?5Al?2Sn?2Zr?4Mo?4Cr合金存在初始屈服现象。当应变为0.5~0.7、变形温度较低、应变速率为0.01 s?1时，原始组织为等轴组织的Ti?5Al?2Sn?2Zr?4Mo?4Cr合金的应变速率敏感性指数值较大，这主要归因于其显微组织演变特征。隋着变形的进行，原始组织为片层组织的Ti?5Al?2Sn?2Zr?4Mo?4Cr合金发生了α片层弯曲和动态球化现象，这使得其应变硬化指数变化显著。当应变为0.15~0.55时，原始组织为片层组织的Ti?5Al?2Sn?2Zr?4Mo?4Cr合金的表观变形激活能更大。
The effects of initial microstructure on the flow stress, strain rate sensitivity (m), strain hardening exponent (n), apparent activation energy (Q) for deformation of Ti?5Al?2Sn?2Zr?4Mo?4Cr alloy were investigated using isothermal compression tests. Results show that the alloy with Widmanst?tten alpha plates shows a higher peak stress and flow softening. Additionally, the alloy with equiaxed primary alpha exhibits an early yield drop at or above 810 °C and at strain rates of 0.1?5.0 s?1. In the strain range of 0.5?0.7,m of the alloy with equiaxed primary alpha is found to be larger at 0.01 s?1 and lower deformation temperatures. This phenomenon could be reasonably explained based on the microstructure evolution. The strain has a significant effect onn of the alloy with Widmanst?tten alpha plates, which is attributed to platelet bending/kinking and dynamic globularization ofα phase. In the strain range of 0.15?0.55,Q of the alloy with Widmanst?tten alpha plates is larger.
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