In this study, the deformation characteristics of as-forged pure tantalum were investigated using a Gleeble-3800 thermal simulation testing machine in the temperature range of room temperature to 350 °C and strain rates ranging from 0.1 to 10 s−1, with a maximum deformation of 60 %. Results show that the deformation resistance increases with decreasing deformation temperature and increasing strain rate before reaching the peak stress. After reaching peak stress, deformation is dominated by dynamic recovery mechanisms. Based on the true stress-strain curves obtained from experiments, the deformation activation energy (Q) and stress exponent (n) of the material were calculated to be 5.133 kJ/mol and 3.1989, respectively. A constitutive equation describing the rheological behavior was established. Utilizing processing maps combined with post-deformation microstructures, optimal processing parameters were determined to be a deformation temperature of room temperature, a strain rate ranging from 3.5 to 10 s−1, and a dissipation rate of 0.12. Under these optimal processing parameters, the material microstructure mainly consisted of dynamically recrystallized grains and deformed grains.

中文翻译：

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锻造纯钽的变形行为和微观组织演变的研究


在本研究中，使用 Gleeble-3800 热模拟试验机在室温至 350 °C 的温度范围内，应变速率为 0.1 至 10 s-1，最大变形为 60 %，研究了锻造纯钽的变形特性。结果表明，在达到峰值应力之前，变形阻力随着变形温度的降低和应变速率的增加而增加。在达到峰值应力后，变形以动态恢复机制为主。根据实验得到的真实应力-应变曲线，计算出材料的变形活化能 （Q） 和应力指数 （n） 分别为 5.133 kJ/mol 和 3.1989。建立了描述流变行为的本构方程。利用加工图与变形后微观结构相结合，确定了最佳加工参数为室温的变形温度、3.5 至 10 s-1 的应变速率和 0.12 的耗散率。在这些最佳加工参数下，材料微观组织主要由动态再结晶晶粒和变形晶粒组成。