形变时效态Al-3.0Cu-1.8Mg-0.5Si合金的强化机制研究  

Study on Strengthening Mechanism of Al-3.0Cu-1.8Mg-0.5Si Alloy Processed by Thermo-mechanical Treatment

作　　者：牛凤姣 伍翠兰[1] 武静 沈书成 罗世芳 NIU Fengjiao;WU Cuilan;WU Jing;SHEN Shucheng;LUO Shifang(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;Modern Engineering Training Center,Chang'an University,Xi'an 710061,China)

机构地区：[1]湖南大学材料科学与工程学院,湖南长沙410082 [2]长安大学现代工程训练中心,陕西西安710061

出　　处：《湖南大学学报（自然科学版）》2022年第6期192-202,共11页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(51831004,52171006,52101007);长安大学中央高校基本科研业务费专项资金资助项目(300102501102);中国交通教育研究会交通教育科学研究课题(JTYB20-102)。

摘　　要：时效前形变的引入,可以改变析出强化型Al-Cu-Mg(-Si)合金的时效析出过程,并且这种变化与形变量直接相关.为研究多元合金的形变强化机制,有必要利用电子背散射衍射(EBSD)、X射线衍射(XRD)、透射电子显微镜(TEM)等多种表征手段,对不同形变时效态Al-3.0Cu-1.8Mg-0.5Si(wt.%)合金的强化方式进行定量或半定量计算,阐述不同强化方式对强度的贡献,为铝合金中形变时效工艺的应用提供理论支撑.研究发现,形变量的提高可以提高合金峰值硬度和强度,原因在于三个方面,一是晶界面积的增加,二是位错密度的增大,三是析出相尺寸更细小、分布更均匀.并且,当形变量大于6%时,形变量越大,析出相对强度的贡献越高.The introduction of deformation before aging can change the aging precipitation process of the precipitation-strengthened Al-Cu-Mg(-Si)alloy,and this change is directly related to the amount of deformation.In order to study the deformation strengthening mechanism of multi-element alloys,it is necessary to use electron backscatter diffraction(EBSD),X-ray diffraction(XRD),transmission electron microscopy(TEM)and other methods to test the Al-3.0Cu-1.8 Mg-0.5Si(wt.%)alloy treated by different deformation and aging process,quantitatively or semi-quantitatively,so that the contribution of different strengthening methods to the strength is listed,which provides theoretical support for the application of thermo-mechanical treatment in aluminum alloys. It is found that the increase in deformation can increase the peak hardness and strength of the alloy due to three reasons.One is the increase of the grain-boundary area,the second is the increase of the dislocation density,and the third is that the size of the precipitates is smaller and the distribution is more uniform. Furthermore,the contribution of precipitates to the strength is getting higher with a larger deformation prior to the aging process,when the amount of deformation is greater than 6%.

关 键 词：铝合金 形变时效 EBSD XRD TEM 

分 类 号：TG113[金属学及工艺—物理冶金] TG146.2[金属学及工艺—金属学]