双重退火对BT25钛合金组织与性能的影响

研究双重退火时不同退火温度对BT25钛合金组织与力学性能的影响。结果表明:双重退火后的室温和高温拉伸性能都强于单一退火,具有良好的综合性能。双重退火时,随着第1退火温度的提高,初生等轴α相含量减少,颗粒逐渐增大,次生α相增多增大;合金的强度降低,塑性及韧性提高。随着第2退火温度的升高α颗粒尺寸稍有增大,球化程度进一步提高;合金强度、塑性及韧性变化不大,高温性能稳定。BT25钛合金采用(940~980)℃×1 h,空冷+(530~570)℃×6 h,空冷的双重退火工艺时,可得到较理想的显微组织和良好的综合性能。

Effect of double annealing on microstructure and properties of BT25 titanium alloy

Effect of different double annealing temperatures on microstructure and mechanical properties of BT25 titanium alloy was investigated The results show that tensile properties of the double annealing at room temperature and high temperature are stronger than that of conventional annealing,and it has good comprehensive properties For the double annealing,with first annealing temperature increasing,the primary equiaxed α-phase size gradually increases,while its content decreases,and the number and the size of secondary α-phase increases At the same time,the alloy strength decreases while plasticity and toughness increase With second annealing temperature increasing,α particle size slightly increases,and the spheroidization degree is further improved In the meantime,the strength,plasticity and toughness of the alloy change a little,in addition,the high temperature property is stable Better microstructure and good mechanical properties of BT25 titanium alloy can be got by using double heat treatment:(940-980)℃×1 h,AC+(530-570)℃×6 h,AC.