Yang Zhijun, Yu Weixin, Lang Shaoting, Wei Junyi, Wang Guanglong, Ding Peng
School of Mechanical and Electrical Engineering, Xinxiang University, Xinxiang 453003, China.
Materials (Basel). 2021 May 9;14(9):2456. doi: 10.3390/ma14092456.
The hot deformation behaviors of a new Ti-6Al-2Nb-2Zr-0.4B titanium alloy in the strain rate range 0.01-10.0 s and temperature range 850-1060 °C were evaluated using hot compressing testing on a Gleeble-3800 simulator at 60% of deformation degree. The flow stress characteristics of the alloy were analyzed according to the true stress-strain curve. The constitutive equation was established to describe the change of deformation temperature and flow stress with strain rate. The thermal deformation activation energy Q was equal to 551.7 kJ/mol. The constitutive equation was ε ˙=e54.41[sinh (0.01σ)]2.35exp(-551.7/RT). On the basis of the dynamic material model and the instability criterion, the processing maps were established at the strain of 0.5. The experimental results revealed that in the (α + β) region deformation, the power dissipation rate reached 53% in the range of 0.01-0.05 s and temperature range of 920-980 °C, and the deformation mechanism was dynamic recovery. In the β region deformation, the power dissipation rate reached 48% in the range of 0.01-0.1 s and temperature range of 1010-1040 °C, and the deformation mechanism involved dynamic recovery and dynamic recrystallization.
采用Gleeble - 3800热模拟试验机，在变形程度为60%的条件下，对一种新型Ti - 6Al - 2Nb - 2Zr - 0.4B钛合金在应变速率0.01 - 10.0 s⁻¹和温度850 - 1060 °C范围内的热变形行为进行了评估。根据真应力 - 应变曲线分析了该合金的流变应力特性。建立了本构方程来描述变形温度和流变应力随应变速率的变化。热变形激活能Q等于551.7 kJ/mol。本构方程为ε˙=e54.41[sinh (0.01σ)]².³⁵exp(-551.7/RT)。基于动态材料模型和失稳判据，在应变为0.5时建立了加工图。实验结果表明，在(α + β)区变形时，在应变速率0.01 - 0.05 s⁻¹和温度920 - 980 °C范围内，功率耗散率达到53%，变形机制为动态回复。在β区变形时，在应变速率0.01 - 0.1 s⁻¹和温度1010 - 1040 °C范围内，功率耗散率达到48%，变形机制包括动态回复和动态再结晶。
