TC17合金的等温转变行为研究

Study on Isothermal Transformation Behavior of TC17 Alloy

摘要:

利用微观组织分析和数值模拟的方法研究了TC17合金的等温转变过程。结果表明，TC17合金首先在晶界或靠近晶界的部位析出α相，随着时效时间的增加，晶粒内部析出大量的针状α相，随着时效温度的降低，析出的α相逐渐变得细小；随着时效温度的降低，析出α相的速率呈现先增大后减小的趋势，在时效温度为600~650 ℃时，相变驱动力和溶质原子的扩散速度达到了最大的匹配度，此时析出α相的速率达到了最大。数值模拟结果表明在等温温度为650 ℃时析出α相的速度最快，该结果和实验结果具有很好的吻合度。

Abstract:

The isothermal transformation process of TC17 alloy was investigated by microstructure analysis and numerical simulation. The experimental results show that TC17 alloy firstly precipitates α phase at or near grain boundaries. And with the increase in aging time, a large number of needle-like α phases precipitated inside the grains, and the precipitated α phase gradually becomes fine with the decrease in aging temperature. With the decrease in the aging temperature, the rate of precipitated α phase shows a tendency of increasing and then decreasing, and both the phase transition driving force and solute atom diffusion rate reach the maximum matching degree at aging temperatures of 600?650 °C. The maximum rate of precipitated α phase is reached currently. At the aging temperature of 600?650 °C, the phase transition driving force and the diffusion speed of solute atoms reach the maximum matching degree, and the rate of precipitating α phase reaches the maximum currently. Numerical simulation results show that the precipitation rate of α phase is the fastest at an isothermal temperature of 650 °C, and the results are in good agreement with the experimental results.