2219铝合金的淬火敏感性  

Quench sensitivity of 2219 aluminum alloy

作　　者：王会敏[1,2] 易幼平[1,2] 黄始全[1,2] 

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083 [2]中南大学机电工程学院,湖南长沙410083

出　　处：《材料热处理学报》2016年第8期67-72,共6页Transactions of Materials and Heat Treatment

基　　金：国家重点基础研究发展规划资助项目(2012CB619504);高性能复杂制造国家重点实验室资助项目(zzyjkt2014-02)

摘　　要：通过分级淬火方法测定了2219铝合金的时间-温度-性能（TTP）曲线。结果表明：合金TTP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相粒子,在440℃附近,析出相（主要为θ平衡相）的析出速率达到最高;随着时间的延长,晶内θ平衡相数量增加、尺寸变大,经时效后晶内析出相θ＇不均匀分布,导致强化效果显著降低,晶内出现无沉淀析出区;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-property（TTP） curves of aluminum alloy 2219 were determined by an interrupted quench method.The results show that the quench sensitive temperature range of the TTP curve of the alloy is 300-480 ℃ with the nose temperature of 440 ℃.Microstructure observation indicates that the supersaturated solid solution can decomposite and particle precipitate during quench process,the precipitation rate is the highest at about 440 ℃.A number of coarse equilibrium θ particles precipitate at grain boundaries and in the grains during isothermal-holding at 440 ℃.Prolonging holding time leads to more and coarser θ particles precipitate in the matrix,which results in loss of solutes and decrease of subsequent aging hardening effect.In the quench sensitive sector,primary precipitating reasons ofθ particles are severe phase transformation driving force and high diffusion rate of solute atoms.According the results,speeding up the cooling rate in the quench sensitive sector to reduce the precipitation of equilibrium phase is meaningful,and at higher temperature,decreasing the cooling rate is helpful to relieve the effect of thermal load.

关 键 词：2219铝合金 TTP曲线 淬火敏感性 时效析出相 

分 类 号：TG146.21[一般工业技术—材料科学与工程]