Spheroidization of the lamellar microstructure in Ti–6Al–4V alloy during warm deformation and annealing
Spheroidization of the lamellar microstructure in Ti–6Al–4V alloy during warm deformation and annealing
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DOI：
10.1016/j.actamat.2011.03.037
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发表时间：
2011-06
期刊：
影响因子：
9.4
通讯作者：
S. Zherebtsov;M. Murzinova;G. Salishchev;S. Semiatin
中科院分区：
文献类型：
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作者：
S. Zherebtsov;M. Murzinova;G. Salishchev;S. Semiatin
研究了Ti-6Al-4V合金中α团组织在温加工及随后600和800 °C退火过程中的球化行为。微观结构演变的主要特征被认为是温度依赖性。在800 °C时，层状组织转变为球状组织主要与经典的边界分裂机制有关，随后通过终止迁移使α粒子进一步球化。而对于较厚的α层片，由于变形过程中的连续动态再结晶，形成了新的晶粒，但球化本身是有限的。温度降低至600 °C导致剪切应变增加、扩散率降低和β相的体积分数降低。因此，薄的β中间层相对快速地转变成单独的颗粒，而α成为基质相。在600 °C的变形/退火过程中，α相的演变与连续动态再结晶有关，只有有限的动态或静态球化。静态球化动力学退火温加工过程中的边界分裂和终止迁移的近似模型的背景下解释。
The spheroidization behavior of an α colony microstructure in Ti–6Al–4V alloy during warm working and subsequent annealing at 600 and 800 °C was established. The principal features of microstructure evolution were found to be temperature dependent. At 800 °C transformation of the lamellar microstrucuture into a globular one was associated primarily with the classical boundary splitting mechanism followed by further spheroidization of α particles by means of termination migration. For thick α lamellae, however, new grains were formed due to continuous dynamic recrystallization during deformation, but spheroidization per se was limited. A decrease in temperature to 600 °C resulted in increased shear strains, lower diffusivity, and a decrease in the volume fraction of the β phase. Consequently, the thin β interlayers transformed relatively quickly into separate particles while α became the matrix phase. Evolution of the α phase during deformation/annealing at 600 °C was associated with continuous dynamic recrystallization with only limited dynamic or static spheroidization. Static spheroidization kinetics during annealing following warm working were explained in the context of approximate models of boundary splitting and termination migration.