【摘要】 利用Gleeble-3500热模拟试验机，在变形温度为613～633 K、应变速率为5×10^-4～1×10^-2 s^-1、总变形量50%的条件下，对Ti_34.88Zr_30.73Cu_8.34Co_4.46Be_21.60合金进行了高温单向热压缩试验，对其热变形行为进行了研究，并绘制了热加工图。结果表明，当应变速率为1×10^-2 s^-1时，不同变形温度均发生脆性断裂现象。应变速率为5×10^-3、1×10^-3 s^-1下，变形温度为613 K时，应力随应变的增加而急剧增加，然后在达到峰值后逐渐下降；当变形温度为623 K时，应力缓慢升高且趋于平稳；当变形温度为633 K时，出现加工硬化现象。当应变速率为5×10^-4 s^-1时，不同变形温度下均表现出加工硬化现象。在变形温度613～623 K、应变速率5×10^-4 s^-1以及变形温度633 K、应变速率1×10^-3 s^-1两个变形区域内，试验合金的能量耗散系数η_p均达0.9以上，适合超塑性变形。结合显微组织观察，在变形温度633 K、应变速率1×10^-3 s^-1条件下，试验合金具有最优的热加工性能。更多还原

【Abstract】 High-temperature uniaxial compression tests were conducted on the Ti_34.88Zr_30.73Cu_8.34Co_4.46Be_21.60 alloy by using Gleeble-3500 thermal simulation machine, under conditions of deformation temperatures ranging from 613 K to 633 K, strain rates from 5×10^-4s^-1 to 1×10^-2s^-1 and total strain of 50%, the hot deformation behavior was studied, and the hot processing diagram was drawn. The results show that brittle fracture occurs at different deformation temperatures and strain rate of 1×10^-2 s^-1. At the strain rate of 5×10^-3 s^-1 and 1×10^-3 s^-1, when the deformation temperature is 613 K, the stress increases sharply with the increase of strain, and then gradually decreases after reaching the peak value; when the deformation temperature is 623 K, the stress rises slowly and tends to be stable; when the deformation temperature is 633 K, work hardening occurs. Under the strain rate of 5×10^-4 s^-1, the work hardening phenomenon is exhibited at different deformation temperatures. In the two deformation regions of deformation temperature of 613-623 K, strain rate of 5×10^-4 s^-1, and deformation temperature of 633 K, strain rate of 1×10^-3 s^-1, the energy dissipation coefficients η_p of the alloy are more than 0.9, which are suitable for superplastic deformation. Combined with the observation of microstructure, the alloy exhibits the optimal hot processing performance under the conditions of deformation temperature of 633 K and strain rate of 1×10^-3 s^-1.更多还原