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在Gleeble—3500型热模拟机上对近α型TA15钛合金进行等温压缩实验,研究不同加热制度对TA15钛合金热变形后微观组织、晶界取向差和晶粒取向的影响。研究结果表明,在两相区(900℃)变形时,常规加热制度下变形后TA15钛合金微观组织主要由原始等轴α相、再结晶α相和马氏体α’相组成,当晶界取向差为40°、60°和90°左右时晶界比例出现峰值;而β相区加热制度下合金变形微观组织主要由片状马氏体α’相、β相和晶界处细小的α相组成,当晶界取向差为60°和90°左右时晶界比例出现峰值,晶粒择优取向性增强。在β单相区(1 050℃)变形时,常规加热制度下变形后合金微观组织中β晶粒晶界清晰,集束特征明显;而β相区加热制度下合金变形微观组织主要由长宽比较大的α’相组成,原始β晶粒消失,当晶界取向差为60°和90°左右时晶界比例出现峰值,晶粒择优取向性减弱,各向同性增强。
The isothermal compression experiments on the near-α TA15 titanium alloy were carried out on a Gleeble-3500 thermal simulator to study the effects of different heating regimes on the microstructure, grain boundary orientation and grain orientation of TA15 titanium alloy after thermal deformation. The results show that the microstructure of TA15 titanium alloy is mainly composed of primary equiaxed α phase, recrystallized α phase and martensite α ’phase when deformed in the two-phase region (900 ℃) When the orientation difference is about 40 °, the grain boundary ratio peaks at about 60 ° and about 90 °. The microstructure of the alloy under the β-phase heating regime is mainly composed of the α ’phase, the β phase and the small α Phase composition, when the grain boundary orientation difference is about 60 ° and about 90 °, the grain boundary peak appears, and the grain preferred orientation enhances. In the deformation of β single-phase zone (1 050 ℃), the grain boundaries of β grain are clear and the cluster characteristics are obvious in the deformation of the alloy under the conventional heating system. The deformation microstructure of the alloy under the heating of β-phase zone mainly consists of the aspect ratio Large α ’phase, the original β grains disappear. When the grain boundary orientation difference is about 60 ° and about 90 °, the grain boundary proportion peaked, the preferred orientation of the grain weakened, and the isotropy was enhanced.