TC11合金高温变形行为及其机理

Hot Deformation Behavior and Deformation Mechanism of TC11 Alloy

采用Gleeble-1500热模拟机研究了TC11合金在800～1050℃、应变速率0．005～5／s条件下的高温变形行为。根据动力学分析，确定了不同温度区间的热激活能和热变形方程，结合变形微观组织观察确定了TC11合金的高温变形机制。结果显示：TC11合金在（α＋β）两相区和β相区的热变形激活能分别为285．38和141．98kJ／mol，表明不同温度区间的热变形机理不同；在两相区变形主要发生片状组织的球化，在B相区变形时低应变速率下（0．005～0．05／s）主要发生β相的动态再结晶，高应变速率下（0．05～5／s）主要发生动态回复。研究结果为确定该合金的最佳变形工艺参数提供了理论依据。

The hot deformation behavior of TCll alloy at temperature range of 800 -1 050℃ and strain rate range of 0. 005 -5/s were studied by compression tests on a Gleeble- 1500 machine. Apparent activation energy and hot deformation equation were determined based on kinetics analysis. Combined with the observation of deformed microstructures, deformation mechanism of TC11 alloy at elevated temperatures was determined. The results showed ： apparent activation energy of TC11 alloy in （ α＋ β） phase field and 13 phase field is 285.38 kJ/mol and 141.98 kJ/mol respectively,which indicates different deformation mechanism in different phase field. Globularization of lamella α is the main deformation mechanism in （ α ＋ β） phase field, while in β phase field, dynamic recrystallization of β phase occurs at low strain rate （0.005 -0.05/s）,and dynamic recovery of β phase occurs at high strain rate （0.05 -5/ s）. All these results provide theory basis for determining the optimum hot deformation process of this alloy.