深冷及时效处理对Mg-7.5Li-3.5Zn-2Y合金组织及力学性能的影响  

Effect of Deep Cryogenic Treatment and Aging Treatment on Microstructure and Mechanical Properties of Mg-7.5Li-3.5Zn-2Y Alloy Sheet

作　　者：徐春杰[1,2] 王弋丹 华心雨 任国璐 李阳 刘君[1] XU Chunjie;WANG Yidan;HUA Xinyu;REN Guolu;LI Yang;LIU Jun(School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China;Xi'an Shechtman Nobel Prize New Materials Institute, Xi'an 710048, China)

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]西安谢赫特曼诺奖新材料研究院,陕西西安710048

出　　处：《铸造技术》2019年第7期633-638,共6页Foundry Technology

基　　金：2018年国家级大学生创新创业训练计划项目(201810700021);陕西省重点研发计划(一般项目-工业领域)项目(2017GY-135)

摘　　要：采用往复挤压和正挤压制备了Mg-7.5Li-3.5Zn-2Y合金30 mm×1 mm厚的带材,对比研究了合金带材经过时效、深冷和时效+深冷处理的组织与性能。结果表明,时效和深冷处理有利于促进第二相沉淀析出,时效+深冷处理工艺可以显著提高镁锂合金的综合力学性能,但要控制合金的时效处理温度和时间以及深冷处理的时间。合金带材经过200℃×2 h时效和-196℃×60 h深冷处理后材料的综合性能最佳,抗拉强度为213 MPa,伸长率为20%,可以满足板材室温大塑性变形对材料综合力学性能的要求。Mg-7.5 Li-3.5 Zn-2 Y alloy sheet with 30 mm wide and 1 mm thick was prepared by reciprocating extrusion(RE)and forward extrusion(EX). The microstructure and properties of alloy sheet after aging, deep cryogenic treatment(DCT)and aging + deep cryogenic treatment(DCT) were investigated. The results show that aging and DCT are conducive to promoting the precipitation of the second phase. aging and DCT can significantly improve the comprehensive mechanical properties of Mg-Li alloys. However, the aging temperature and time of the alloy as well as the time of DCT should be controlled. After aging at 200 ℃ for 2 h and DCT at-196 ℃ for 60 h, the alloy sheet has the best comprehensive properties, with tensile strength UTS of 213 MPa and elongation of 20%, which can meet the requirements for comprehensive mechanical properties of materials under large plastic deformation at room temperature.

关 键 词：MG-LI合金 深冷处理 时效处理 组织与性能 

分 类 号：TG156[金属学及工艺—热处理] TG113[金属学及工艺—金属学]