Ti53311S钛合金热变形的组织和机制分析

用Gleeble-1500型热模拟试验机对Ti53311S钛合金在温度为880～1080℃,应变速率为0.001～10 s-1的条件下进行高温压缩变形行为的研究.测试了其真应力.真应变曲线,采用双曲正弦本构方程计算出激活能,双相区为641 kJ/mol,β相区为244 kJ/mol.观察了变形后的显微组织,并分析了其变形机制.结果表明:该合金对温度和应变速率敏感,不同变形条件下应力值变化很大;应变速率敏感指数(m)随温度升高而降低,而变形激活能(Q)随温度升高而增大.合金的变形机制在双相区为晶界滑移和晶粒球化,在β单相区为动态回复.

Hot Deformation Microstructure and Mechanism of Ti53311S Titanium Alloy

The hot deformation behavior of Ti53311S titanium alloy in the temperature range of 880～1080℃and strain rate range of 0.001-10 s-1 have been studied by using hot compressing testing on a Gleeble-1500 simulator.The flow behavior was described by the hyperbolic sine constitutive equation,the activation energies in(α+β)region and in β region were calculated,they are 641 kJ/mol and 244 kJ/mol,respectively.The microstructure of Ti53311S was observed and analyzed using an optical microscope.The experimental results show that this alloy is sensitive to deformation temperature and strain rate,and the strain rate sensitivity exponent values(m)decrease with increasing of deformation temperature,the leading deformation mechanism in the single phase β region is dynamic recover,while that in (α+β) region is grain boundary slipping and grain globularizing.