Influence of pre-stretching on quench sensitive effect of high-strength Al-Zn-Mg-Cu-Zr alloy sheet  

预拉伸对高强Al-Zn-Mg-Cu-Zr合金板材淬火敏感性效应的影响

作　　者：HE Ke-zhun LI Qun LIU Sheng-dan ZHANG Xin-ming ZHOU Ke-chao 何克准;李群;刘胜胆;张新明;周科朝(Powder Metallurgy Research Institute,Central South University,Changsha 410083,China;Guangxi Alnan Institute of Aerospace Transit Aluminum Alloy and Application,Nanning 530031,China;Guangxi Alnan Aluminium Inc.,Nanning 530031,China;School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]Powder Metallurgy Research Institute,Central South University,Changsha 410083,China [2]Guangxi Alnan Institute of Aerospace Transit Aluminum Alloy and Application,Nanning 530031,China [3]Guangxi Alnan Aluminium Inc.,Nanning 530031,China [4]School of Materials Science and Engineering,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2021年第9期2660-2669,共10页中南大学学报（英文版）

基　　金：Project(AA17202007) supported by the Special Funding for Innovation-Driven Development of Guangxi Province,China。

摘　　要：The influence of pre-stretching on quench sensitive effect of high strength Al-Zn-Mg-Cu-Zr alloy AA 7085 sheet was investigated by tensile testing at room temperature,transmission electron microscopy(TEM)and differential scanning calorimetry(DSC).The water-cooled and aged alloy exhibits higher strength than the air-cooled and aged alloy;2.5%pre-stretching of tensile deformation exerts little effect on strength of water-cooled and aged alloy but increases that of air-cooled and aged one,and therefore the yield strength reduction rate due to slow quenching decreases from about 3.8%to about 1.0%,reducing quench sensitive effect.For the air-cooled alloy,pre-stretching increases the sizes ofη'strengthening precipitates but also increases their quantity and the ratio of diameter to thickness,resulting in enhanced strengthening and higher strength after aging.The reason has been discussed based on microstructure examination by TEM and DSC.通过室温拉伸测试、透射电子显微镜(TEM)、差示扫描量热法(DSC)研究了预拉伸对高强Al-ZnMg-Cu-Zr合金AA7085板材淬火敏感性效应的影响。结果表明:水冷及时效合金的强度高于空冷及时效合金的;2.5%预拉伸变形对水冷及时效合金的强度影响很小,但增强了空冷及时效合金的强度,使慢冷导致的屈服强度下降率从约3.8%减小至约1.0%,因而降低了淬火敏感效应。对于空冷合金,预拉伸增加了η'强化相的尺寸,也增加了其数量及直径厚度比值,以获得更好的时效强化效果及更高的强度。基于TEM和DSC的表征结果对原因进行了讨论。

关 键 词：high-strength aluminum alloy PRE-STRETCHING tensile properties quench sensitive effect strengthening precipitates 

分 类 号：TG146.21[一般工业技术—材料科学与工程]