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采用Gleeble热模拟试验机对2124铝合金进行热压缩试验,通过分析合金在高温塑性变形过程中的流变应力变化规律,以及利用光学显微镜和透射电镜观察合金在热变形过程中的显微组织演变,探讨了不同变形温度和应变速率对合金热塑性变形能力的影响。结果表明,2124铝合金在热变形中的流变应力稳态值随热变形温度的升高或应变速率的减小而增大,可用双曲正弦形式的本构方程来描述热变形条件和流变应力的关系,合金的变形激活能为170.13 k J/mol。在较低变形温度或较高应变速率下,热变形后合金组织中存在大量位错缠结和位错墙,软化机制主要为动态回复。随变形温度的升高或者应变速率的降低,该合金组织中出现了再结晶晶粒,软化机制逐渐向动态再结晶转变。
The hot compressive test of 2124 aluminum alloy was carried out by Gleeble thermal simulator. The change of flow stress in the process of plastic deformation at high temperature was analyzed, and the microstructure evolution of the alloy during thermal deformation was observed by optical microscope and transmission electron microscope The effects of different deformation temperature and strain rate on the thermoplastic deformation of the alloy were discussed. The results show that the steady-state value of flow stress in hot deformation of 2124 aluminum alloy increases with the increase of heat distortion temperature or strain rate. The constitutive equation of hyperbolic sine form can be used to describe the thermal deformation conditions and flow Stress-strain relationship, the alloy deformation activation energy of 170.13 k J / mol. At lower deformation temperature or higher strain rate, there are a lot of dislocation entanglement and dislocation wall in the alloy after hot deformation. The softening mechanism is mainly dynamic recovery. With the increase of deformation temperature or the decrease of strain rate, recrystallized grains appear in the alloy structure, and the softening mechanism gradually changes to dynamic recrystallization.