成形及退火温度对TA5钛合金显微组织和力学性能的影响

研究了不同成形及退火温度下TA5钛合金棒材显微组织及室温拉伸性能的变化规律。试验结果表明,T_β之上成形的棒材组织存在明显的晶界析出物且晶内分布有沿特定方向析出的点状析出物;T_β之下成形的棒材组织以晶内点状析出物为主,伴随少量晶界析出物,且随着退火温度的升高,再结晶体积分数升高,晶粒尺寸增大。相比于T_β之上成形的棒材,T_β之下成形有利于材料的塑性,但会降低材料的强度;随退火温度的上升,材料呈现强度降低、塑性上升的趋势。

Effects of Forming and Annealing Temperature on Microstructure and Mechanical Properties of TA5 Titanium Alloy

The microstructure evolution and mechanical properties of TA5 titanium alloy bars under different forming and annealing temperatures were studied.The results show that there are obvious grain boundary precipitates and intra-granular point-like precipitates precipitated in a specific direction in the bar formed above T_β;the microstructure of the bar formed below T_βis composed of intra-granular point-like precipitates with a small amount of grain boundary precipitates.With the annealing temperature increases,the recrystallized volume fraction and the grain size increases.Compared with the bar formed above T_β,forming below T_βis beneficial to the plasticity of the material,but it will reduce the strength of the material.With the annealing temperature rises,the material shows a trend of decreasing strength and increasing plasticity.