采用分级淬火方法测定2219铝合金的时间−温度−电导率(TTT)曲线。利用EDS和TEM等分析手段并结合Avrami方程，研究2219铝合金在等温过程中的组织变化和相变动力学。结果表明：合金TTT曲线的鼻尖温度为440℃，淬火敏感温度区间为300~480℃；等温保温时，过饱和固溶体分解析出第二相粒子，在440℃附近，第二相(主要为θ平衡相)的析出速率达到最高；鼻尖温度的高相变驱动力和较快的扩散速率是θ相析出和长大的主要原因，建议在淬火敏感区间应加快淬火冷却速率避免粗大平衡相的析出，而高于淬火敏感区间温度时可适当降低冷却速率减小热应力的影响。%The time-temperature-transformation (TTT) curves of 2219 aluminum alloy were determined by an interrupted quench method. The microstructure evolution and phase transformation kinetics during isothermal treatment were studied by TEM,EDS and Avrami equation. The results show that the quench sensitive temperature range of TTT curve of alloy is 300−480℃ with the nose temperature of 440℃. Microstructure observation indicates that the supersaturated solid solution decomposes, and particles precipitate during quench process. The precipitation rate is the highest at about 440℃. In the quench sensitive sector, primary reasons ofθ phase transformation are severe driving force, and high diffusion rate of solute atoms. According to the results, increasing the cooling rate in the quench sensitive sector to reduce the precipitation of equilibrium phase is meaningful. At a higher temperature, decreasing the cooling rate is helpful to relieve the effect of thermal stress.
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