Yb微合金化对Al-Zn-Mg-Cu合金组织和性能的影响  

Effect of Yb Microalloying on Microstructure and Properties of Al-Zn-Mg-Cu Alloy

作　　者：许永祥 朱梦真 方华婵[1] 张茁 段志英 孙振 Xu Yongxiang;Zhu Mengzhen;Fang Huachan;Zhang Zhuo;Duan Zhiying;Sun Zhen(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Advance Research Center,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]中南大学高等研究中心,湖南长沙410083

出　　处：《稀有金属材料与工程》2023年第10期3556-3562,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金青年基金(51501228);湖南省自然科学基金(2015JJ3167);中南大学大型仪器设备共享基金(CSUZC202109);中南大学研究生自主创新项目(1053320192832)。

摘　　要：采用熔炼铸造的方法,结合热挤压变形和固溶时效等工艺制备了Al-Zn-Mg-Cu和Al-Zn-Mg-Cu-Yb 2种合金。利用金相显微镜、扫描电镜、透射电镜对组织结构进行观察,采用差热分析仪、拉伸试验机和电化学工作站对性能进行检测,研究了稀土Yb微合金化对Al-Zn-Mg-Cu合金组织和性能的影响。结果表明:Yb的添加能够明显细化晶粒,显微硬度和抗拉强度分别由1230.881 MPa、562.9 MPa提高至1518.02 MPa、616.3 MPa,拉伸断裂形式也由沿晶和韧窝共存的混合型断裂转变为完全的韧窝型断裂。然而基体中Al8Cu4Yb粗大相的析出及晶界处η相的连续分布,对合金耐腐蚀性能不利。Al-Zn-Mg-Cu and Al-Zn-Mg-Cu-Yb alloys were prepared by melting casting,hot extrusion deformation and solution aging.The effect of rare earth Yb microalloying on the microstructure of Al-Zn-Mg-Cu alloy was observed by optical microscope,scanning electron microscope and transmission electron microscope,and the properties were tested by differential thermal analyzer,tensile tester and electrochemical workstation.The results show that the addition of Yb can obviously refine the grains,and the microhardness and tensile strength increase from 1230.88 MPa and 562.9 MPa to 1518.05 MPa and 616.3 MPa,respectively.The tensile fracture mode also changes from intergranular fracture and dimple fracture mixing to complete dimple fracture.However,the precipitation of coarse Al8Cu4Yb phase in the matrix and the continuous distribution of η phase on grain boundaries are unfavorable to the corrosion resistance.

关 键 词：AL-ZN-MG-CU合金 Yb微合金化 细化晶粒 拉伸断口 耐腐蚀性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]