800MPa级Al-Zn-Mg-Cu系合金  

Al-Zn-Mg-Cu Alloys with Strength of 800MPa

作　　者：杨守杰 邢清源 于海军 王玉灵 戴圣龙 YANG Shou-jie;XING Qing-yuan;YU Hai-jun;WANG Yu-ling;DAI Sheng-long(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Beijing Engineering Technology Research Center of Advanced Aluminum Materials and Application,Beijing 100095,China)

机构地区：[1]中国航发北京航空材料研究院,北京100095 [2]北京市先进铝合金材料及应用工程技术研究中心,北京100095

出　　处：《材料工程》2018年第4期82-90,共9页Journal of Materials Engineering

基　　金：国防基础科研计划资助项目(JCKY2016205C009)

摘　　要：通过采用在线精炼、在线细化、热顶铸造等技术手段,成功在直接水冷半连续铸造设备上制备出了合金化元素总量达20%的Al-Zn-Mg-Cu系合金,打破了7000系铝合金合金化元素总量不高于14%的极限。利用金相显微镜、透射电镜进行微观组织观察,采用差热分析仪测试相转变温度,测试了硬度、拉伸性能并利用扫描电镜进行断口分析。该合金经过挤压、RRA热处理后,其抗拉强度、屈服强度和伸长率分别达到810.3,799.3MPa和3.4%。通过对单级时效动力学和三级时效动力学进行研究,确定了合金的最佳时效温度为120℃,而时效时间的可选择范围较大。Zn含量高达16.1%的铝合金中主要由未溶第二相和时效析出相η′相共同强化,未发现其他新析出相。This research has produced Al-Zn-Mg-Cu alloy containing 20%(mass fraction,the same below)alloying elements by the Hot-top semi-continuous DC casting equipment,which has adopted purifying and refining on-line technologies.This alloy has broken the limit of 7000 Al-alloy containing no more than 14%alloying elements.The microstructure and fracture of the alloy were investigated by optical microscopy(OM),transmission electron microscopy(TEM)and scanning electron microscopy(SEM),the temperature of phases transformation was investigated by differential scanning calorimetry(DSC),and the hardness and tensile properties were also tested.The tensile strength,yield strength and elongation of this alloy can be up to 810.3,799.3MPa and 3.4%by RRA heat-treatment after extrusion.Through the study on the single and tertiary-stage ageing treatment kinetics,the optimum ageing temperature 120℃is identified and a wider range of aging time can be chosen.Moreover,no other precipitates are found in the alloy containing 16.1%Zn element,and the joint strengthening comes from the undissolved second phase and the ageing precipitationη′phase.

关 键 词：超高强铝合金 DC铸造 RRA热处理 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]