Behavior and modeling of high temperature deformation of an α + β titanium alloy
Behavior and modeling of high temperature deformation of an α + β titanium alloy
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DOI：
10.1016/j.msea.2012.06.039
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发表时间：
2012-10
期刊：
影响因子：
6.4
通讯作者：
Yadong Qu;Minmin Wang;L. Lei;Xu Huang;Liqiang Wang;J. Qin;W. Lu;Di Zhang
中科院分区：
文献类型：
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作者：
Yadong Qu;Minmin Wang;L. Lei;Xu Huang;Liqiang Wang;J. Qin;W. Lu;Di Zhang
在Gleeble-3500型等温恒应变速率压缩试验机上，研究了铸态ATI425钛合金在不同温度(95 0~115 0℃)和不同应变速率(0.001~1s−1)条件下的变形行为。α+β和β单相场的微观结构观察分别显示了血小板α球化和β的动态恢复。以Arrhenius关系的形式建立了描述流动应力与工艺参数的函数的本构方程。计算的表观激活能为155±15kJ/mol，表明变形机制为位错攀移/滑移控制。根据动态材料模型和Prasad的失稳判据生成加工图。研究了具有峰值效率>；0.48和流动不稳定性的磁区，并通过显微组织观察确定和验证了这些区域发生变形的证据。对于钢锭的破裂，建议在T>；1100℃和ε·>；0.1 S−1下变形，高度变形量大于50%才能获得进一步的再结晶组织。
The deformation behavior of as-cast ATI 425 titanium alloy was studied using isothermal, constant strain rate compression carried out on a Gleeble-3500 testing system under conditions of varying temperature (950–1150°C) and strain rates (0.001–1s−1) up to a height reduction of 50%. Microstructure observations in α+β and single β phase fields showed the globularization of the platelet α and dynamic recovery of β, respectively. Constitutive equation describing the flow stress as a function of the processing parameters was proposed in the form of Arrhenius-type relationship. The calculated apparent activation energy of 155±15kJ/mol suggested a dislocation climb/slip controlled deformation mechanism. Processing map was generated according to dynamic material model and Prasad's instability criterion. Domains with peak efficiency >0.48 and flow instability were investigated and the evidences of deformation in these regions were identified and validated through microstructure observations. For ingot breakdown, deformation at T>1100°C and ε˙>0.1 s−1was suggested and height reduction bigger than 50% was needed to get a further recrystallized microstructure.