二次热压缩对Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr合金组织和性能的影响  

Effect of hot compression-ECAP-hot compression on microstructure and properties of Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr alloy

作　　者：张晓宇[1] 许晓静[1] 陈瑞芳[1] 徐驰[1] 刘志刚[1] 童浩[1] ZHANG Xiao-yu;XU Xiao-jing;CHEN Rui-fang;XU Chi;LIU Zhi-gang;TONG Hao(Engineering Institute of Advanced Manufacturing and Modern Equipment Technology,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]江苏大学制造与现代装备技术工程研究院,江苏镇江212013

出　　处：《轻合金加工技术》2018年第10期34-42,共9页Light Alloy Fabrication Technology

基　　金：江苏省科技成果转化专项基金,项目号(BA2016126)

摘　　要：等通道转角挤压技术(ECAP)能够有效细化晶粒的同时使得合金组织趋于均匀化。采用X射线衍射分析(XRD)、电子背散射衍射分析(EBSD)、电导率测试、硬度测试、晶间腐蚀试验等方法研究了Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr合金热压缩-EACP之后,预回复固溶时效处理前的二次热压缩处理对合金组织、性能及其各向异性的影响。结果表明,铝合金经过热压缩-ECAP-热压缩-预回复-固溶-时效处理后,相对于未经二次热压缩的,Z方向的平均晶粒尺寸从21.287μm减小到12.946μm,低角度晶界比例从68.6%增加到71.4%,合金的电导率由24.4%IACS增大到26.1%IACS。Y方向上的屈服强度由586.3 N/mm^2提高至606.9 N/mm^2,抗拉强度由635.1 N/mm^2提高到了654.4 N/mm^2,同时一定程度地提高了合金三个方向的晶间腐蚀性能。根据Hall-petch理论得出晶粒细化是合金的屈服和拉伸强度得到提升的主要原因,合金内部各向异性的降低主要是由于二次热压缩带来的合金晶体取向的改变以及晶内沉淀析出相特征的改变导致的。The technology of the equal channel angular pressing （ECAP） can refine the grains effectively and homogenize the microstructure. After the process of ECAP, the effect of the secondary hot-compression before the prerecovery-solution-aging treatment on the mi-crostructure, mechanical properties and anisotropy of the Al-13.0Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr alloy was investigated by means of XRD, EBSD, conductivity, hardness and interg- ranular corrosion tests. The results show that the average grain sizes of the alloy are de-creased from 21. 287 μm to 12. 946 μm in the Z direction and the proportion of low angle grain boundary is increased from 68.6% to 71.4% after the process of hot compression- ECAP-hot compression-prerecovery-solution-aging, and the conductivity of the alloy goes up to 26.1% IACS from 24.4% originally. The yield strength in the Y direction goes from 586.3 N/mm^2 to 606.9 N/mm^2 and the tensile strength from 635. 1 N/mm^2 to 654.4 N/mm^2. Additively, the intergranular corrosion of the alloy is improved to a certain extent. The resulting mechanical properties such as yield and tensile strength are increased with grain refinement that is connected with the Hall-peteh theory. The change of the alloy＇s crys- tal orientation and the intracrystalline precipitated phase by the secondary hot compression process result in the decrease of the internal anisotropy aluminum alloy.

关 键 词：AL-ZN-MG-CU合金 热压缩 ECAP 强化机制 各向异性 

分 类 号：TG146.21[一般工业技术—材料科学与工程]