固溶时效处理对快速凝固LAZ941-0.5Y镁锂合金组织和硬度的影响  

Effect of solution and aging treatment on microstructure and hardness of rapidly solidified LAZ941-0.5Y magnesium-lithium alloy

作　　者：李甜甜 李丽华[1,2] 顾永军 李谦[1] 黄金亮[1,2] LI Tian-tian;LI Li-hua;GU Yong-jun;LI Qian;HUANG Jin-liang(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471023,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳471023

出　　处：《材料热处理学报》2022年第1期54-60,共7页Transactions of Materials and Heat Treatment

基　　金：河南省重大科技攻关项目(1812002122800)。

摘　　要：通过光学显微镜(OM)、X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和显微硬度仪等研究了固溶时效处理对快速凝固Mg-9Li-4Al-1Zn-0.5Y(LAZ941-0.5Y)镁锂合金的组织和硬度的影响。结果表明:经固溶处理后,合金的显微组织粗化,第二相主要弥散分布在α-Mg相和β-Li相中及它们的相界处;XRD分析结果表明,与传统凝固相比,快速凝固态合金中的相种类没有发生显著变化,仍为α-Mg、β-Li、AlLi和Al_(2)Y相,但也出现了新的Mg_(24)Y_(5)物相和Mg_(17)Al_(12)相。合金薄带经固溶时效处理后,XRD显示合金物相的种类并没有发生显著变化,但经400℃固溶0.5 h后,部分AlLi和Mg_(17)Al_(12)相溶入基体;100℃时效0.25 h后,合金相呈弥散分布,且多数合金相的内部有纳米级颗粒物出现;这种内含纳米级颗粒物的合金相的沉淀强化作用使得合金薄带的显微硬度达到最大值,由快速凝固态的92.2 HV0.025增至108.1 HV0.025,提高了约17%。Effect of solution and aging treatment on microstructure and hardness of rapidly solidified Mg-9Li-4Al-1Zn-0.5Y alloy(LAZ941-0.5Y)was studied by means of optical microscope(OM),X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and microhardness tester.The results show that the microstructure of the rapidly solidified alloy is coarsened after solution treatment,and the second phase is mainly dispersed inα-Mg phase,β-Li phase and their grain boundaries.XRD analysis results show that compared with the traditional solidified alloy,the phase types of the rapid solidified alloy have not changed significantly,and are stillα-Mg,β-Li,AlLi and Al_(2) Y phases,but new Mg_(24) Y5 phase and Mg_(17) Al_(12) phase also appeared.After solution and aging treatment,XRD analysis results show that the phase types of the alloy phase do not change significantly,but after solution treatment at 400℃for 0.5 h,some AlLi and Mg_(17) Al_(12) phases dissolve into the matrix.After aging at 100℃for 0.25 h,the alloy phase is dispersed uniformity,and nano particles appear in most alloy phases.The precipitation strengthening effect of the alloy phase containing nano particles makes the microhardness of the alloy strip reach the maximum,which increases from 92.2 HV0.025 to 108.1 HV0.025,an increase of about 17%.

关 键 词：镁锂合金 快速凝固 固溶处理 时效 显微硬度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]