7050铝合金模锻件淬火过程析出动力学行为  

Behavior of Precipitation Kinetics of 7050 Aluminum Alloy Die Forgings in Quenching Processes

作　　者：吴书舟[1,2] 易幼平 黄始全[1,2] WU Shu- zhou1,2 ,YI You-ping1,2, HUANG Shi-quan1,2(1.College of Mechanical and Electrical Engineering,Central South University, Changsha 410083 ,China;2.State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China)

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

出　　处：《材料工程》2018年第11期118-124,共7页Journal of Materials Engineering

基　　金：国家重点基础研究发展计划项目(2012CB619504);江苏省科技计划项目(BA2015075);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7050铝合金模锻件的TTP曲线。利用TEM分析、JMA方程探究第二相脱溶析出机理和强化机制。结果表明:合金TTP曲线的鼻尖温度为337℃,敏感区间为270～400℃,淬火敏感性高温<低温<中温,孕育期提前至0.7s;合金等温保温以Al3Zr粒子为形核脱溶,早期η相优先析出,晶界粗化程度随温度升高而降低;保温时间延长后,低温段晶内析出弥散针状S相,中高温段S相析出减少,η相聚集吞并长大,晶界粗化且连续,随温度升高η相数量减少尺寸增大;脱溶析出相的强化效果为GP区+η′相>针状S相>棒状η相。The time-temperature-property（TTP）curves of 7050 aluminum alloy die forgings were determined by an interrupted quenching method.The second phase dissolving and precipitation mechanism and the strengthening mechanism were studied by TEM and JMA equation.The results show that the nose temperature and incubation period of TTP curves are 337℃and 0.7 s,with the quenching sensitivity range 270-400℃.Low level of the quenching sensitivity to sort the result followed by high temperature,low temperature,medium temperature;Al3 Zr particles are the primary nuclear sites of supersaturated solid solution,whose main precipitate phases areηparticles during early isothermal process,with the increase of temperature,the grain boundary becomes narrower;after the holding time is prolonged,needle dispersion S phases are the main precipitates of the alloy in the low temperature range;in the medium and high temperature range,a large number ofηparticles precipitate and aggregate,accompanied by the decrease of volume fraction of S phases,meanwhile the grain boundary becomes coarser and continuous;with the temperature rising,the size ofηparticles increases while the amount decreases;the rank of strength levels of precipitation is GP zones andη′phases,needle-like S phases,clubbedηphases.

关 键 词：TTP曲线 淬火敏感性 析出机理 强化相 

分 类 号：TG146.21[一般工业技术—材料科学与工程]