铸造工艺对Mg-12Zn-1Y合金组织与力学性能的影响
Effects of Casting Process on Structure and Mechanical Properties of Mg-12Zn-1Y Alloy
伍德超 1方晓刚 2张天阳 1刘继广 1杨友文 1吕书林 3吴树森3
作者信息
- 1. 合肥工业大学材料科学与工程学院,合肥 230009;高性能铜合金材料及成形教育部工程研究中心,合肥 230009
- 2. 合肥工业大学材料科学与工程学院,合肥 230009;高性能铜合金材料及成形教育部工程研究中心,合肥 230009;华中科技大学材料成形与模具技术全国重点实验室,武汉 430074
- 3. 华中科技大学材料成形与模具技术全国重点实验室,武汉 430074
- 折叠
摘要
特定Zn、Y含量的Mg-Zn-Y合金能原位形成二十面体准晶增强I相(I-Mg3Zn6Y),但常规铸造凝固条件下形成的准晶组织粗大,难以发挥其性能优势.研究了重力铸造、挤压铸造及流变挤压铸造工艺制备的Mg-12Zn-1Y合金的组织和力学性能.结果表明,在重力铸造的合金组织中,大量粗大的I相和Mg7Zn3相聚集在一起.挤压铸造使I相转变为细小的层片状,且Mg7Zn3含量降低.对于流变挤压铸造的合金,随着制浆过程中超声功率增大,α-Mg晶粒得到较大程度的细化和球化,共晶组织间距明显减小,而随着超声功率持续增加到2 400 W时,共晶组织出现一定程度富集.当超声功率为1 600 W时,合金的力学性能最优,屈服强度、抗拉强度和伸长率分别为185 MPa、276 MPa和6.8%,相较于挤压铸造分别提高了35.0%、24.9%和142.9%.
Abstract
The icosahedral quasicrystal I-phase(Mg3Zn6Y)can be formed in the Mg-Zn-Y alloys with specific Zn and Y content,of which the microstructure in the conventional casting is usually coarse and difficult to exert performance advantages.The microstructure and mechanical properties of Mg-12Zn-1Y alloy prepared by gravity casting,squeeze casting and rheo-squeeze casting(RSC)were investiagted.The results reveal that in the gravity casting specimen,a large number of I-phase and Mg7Zn3 phase are gathered,while the squeeze casting process contributes to the morphol-ogy transformation of I-phase into fine lamellar,and the decrement of Mg7Zn3 phase.In the RSC process,with the increase of ultrasonic power applied during the stage of slurry-preparation,α-Mg grains are significantly refined and spheroidized,and the lamellar spacing of eutectic structure is obviously reduced.However,the concentration of eutectic structures appears when ultrasonic power continually is increased to 2 400 W.When the ultrasonic power is 1 600 W,the mechanical properties of the alloy are desirable,where the yield strength,tensile strength and elongation reach 185 MPa,276 MPa and 6.8%,which are 35.0%,24.9%and 142.9%higher than those of squeeze casting ones,respectively.
关键词
Mg-Zn-Y合金/准晶/铸造工艺/微观组织/力学性能Key words
Mg-Zn-Y Alloy/Quasicrystal/Casting Process/Microstructure/Mechanical Properties引用本文复制引用
基金项目
国家自然科学基金资助项目(52071123)
安徽省自然科学基金资助项目(1908085QE197)
中央高校基本科研业务费专项资金资助项目(PA2022GDGP0029)
出版年
2024
NETL
NSTL
万方数据