冷却速率对7050铝合金淬火析出行为的影响  

Effect of cooling rate on quenching precipitation behavior of 7050 aluminum alloy

作　　者：李承波 赵偲[1] 肖博 朱戴博 张新明 LI Chengbo;ZHAO Cai;XIAO Bo;ZHU Daibo;ZHANG Xinming(School of Mechanical Engineering and Mechanics,Xiangtan University,Xiangtan 411105,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China;Guangdong Xingfa Aluminum Co.,Ltd.,Guangdong,Foshan 528137,China)

机构地区：[1]湘潭大学机械工程与力学学院,湘潭411105 [2]中南大学材料科学与工程学院,长沙410083 [3]广东兴发铝业有限公司,佛山5281371

出　　处：《中国有色金属学报》2024年第3期739-750,共12页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(52205421);广西科技重大专项(桂科AA23023028);广东省重点实验室开放基金资助项目(XF20230330-XT)。

摘　　要：基于末端淬火的高通量实验,结合扫描电子显微镜(SEM)、电子背散射衍射(EBSD)、透射电子显微镜(TEM)、高分辨率透射电子显微镜(HRTEM)和扫描透射电子显微镜(STEM)研究了7050铝合金的淬火析出行为。结果表明:随着冷却速率的降低,电导率增加,淬火析出相的种类和形核位置均增加。有利形核析出的位置顺序为大角度晶界、小角度晶界(亚晶界)、再结晶晶内(Al_(3)Zr粒子)、位错和亚晶内(Al_(3)Zr粒子)。淬火析出相的析出顺序为η相、S相、T相和Y相。随冷却速率的降低,η相依次在大角度晶界、小角度晶界、再结晶晶内(Al_(3)Zr粒子)和部分亚晶内析出;当冷却速率低于630℃/min时,S相在亚晶(界)析出,T相在再结晶晶内(Al_(3)Zr粒子)和高位错密度的亚晶(界)处析出;当冷却速率低于164℃/min时,Y相在亚晶的位错处析出,η相和T相也在亚晶内析出。The quenching precipitation behavior of 7050 aluminum alloy was studied by high-throughput experiment based on end-quenching,combined with scanning electron microscopy(SEM),electron backscattering diffraction(EBSD),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM)and scanning transmission electron microscopy(STEM).The results show that,with the decrease of cooling rate,the electrical conductivity increases,and the types and nucleation locations of quenching precipitates increase.The position order of favorable nucleation precipitation is high angle grain boundary,low angle grain boundary(subgrain boundary),recrystallization grain(Al_(3)Zr particles),dislocation and subgrain(Al_(3)Zr particles).The precipitation sequence of the quenching precipitated phase isηphase,S phase,T phase and Y phase.With the decrease of cooling rate,ηphase precipitates in high angle grain boundaries,low angle grain boundaries,recrystallization(Al_(3)Zr particles)and part of subgrains successively.When the cooling rate rate is lower than 630℃/min,the S phase precipitates in subgrains(boundaries),and the T phase precipitates in recrystallized grains(Al_(3)Zr particles)and subgrains(boundaries)with high dislocation density.When the cooling rate is lower than 164℃/min,Y phase precipitates at the dislocation of subgrains,ηphase and T phase also precipitate inside subgrains.

关 键 词：7050铝合金 末端淬火 显微组织 非均匀析出 

分 类 号：TG146.2[一般工业技术—材料科学与工程]