Ti-6Al-4V合金中β_1→α+β_2相变动力学研究

Study on β_1→α+β_2 transformation kinetics of Ti-6Al-4V alloy

利用差示扫描量热仪测试了Ti-6Al-4V合金在不同冷却速度下β1→α+β2相变的温度和时间,并计算其相变激活能和Avrami指数。结果表明,在5~20℃/min冷却速度范围,冷却速率越大,Ti-6Al-4V合金中的β1→α+β2相变温度越低,相变时间也越短,其相变激活能随着相变体积分数的增加而逐渐减小,在660℃时,Avrami指数在1~2之间。

The temperature and duration of β1→α + β2transformation of Ti-6Al-4V alloy in cooling process were measured by diferential scanning calorimetry( DSC),and transformation activation energy and Avrami exponent of β1→α + β2were also calculated. The results show that when the cooling rate is in the range of 5-20 ℃ /min,the transformation temperature and the transformation duration β1→α + β2transformation of Ti-6Al-4V alloy decrease with the cooling rate increasing,its transformation activation energy decreases with the phase transformation volume fraction increasing,and Avrami exponent is between 1 and 2 at 660 ℃.