Effect of Y and Ce addition on microstructures and mechanical properties of LZ91 alloys
Effect of Y and Ce addition on microstructures and mechanical properties of LZ91 alloys
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Y和Ce添加对LZ91合金显微组织和力学性能的影响
DOI：
10.1016/j.jallcom.2019.06.003
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发表时间：
2019-09-05
影响因子：
6.2
通讯作者：
Zhang, Milin
中科院分区：
文献类型：
--
作者：
Ji, By Qing;Ma, Yajun;Zhang, Milin
Mg-9Li-1Zn(LZ91)作为一种双相镁锂合金越来越受到人们的关注，但其强度还有待进一步提高。研究了Y、Ce不同配比对LZ91钢组织和力学性能的影响。研究了添加Y和Ce的铸态和冷轧LZ91合金的组织和性能。稀土元素Y和Ce的加入细化了LZ91的晶粒度。Y显著强化了LZ91合金，而Ce则减弱了Y的强化作用。随着Y和Ce含量的增加，合金的力学性能呈现先升后降的趋势，但与LZ91合金相比，仍表现出一定的强化效果。Y的加入导致了Mg24Y5和Mg12ZnY的形成。Ce的加入，形成了连续网状分布的Mg12Ce和CeZn5。在铸态和冷轧状态下，由于Y对α相的显著细化作用和镁合金的弥散强化作用，Mg-9Li-1Zn-1.5Y合金在铸态(UTS、YS和伸长率分别为162、130和49.6%)和冷轧状态(UTS、YS和伸长率分别为255、231和31.9%)下具有最好的组织和性能。同时，冷轧后的Mg-9Li-1Zn-1.5Ce的延伸率异常提高。这解释了铸态粗大的Mg12Ce在冷轧后被分解成细小弥散的颗粒。为双相镁锂合金中稀土元素的选择和定量提供了参考。这也为细化双相镁锂合金中的大尺寸第二相提供了参考。(C)2019爱思唯尔B.V.保留所有权利。
As a duplex Mg-Li alloy, Mg-9Li-1Zn (LZ91) has attracted increasing attention, but its strength needs to be further improved. This paper aims to explore the effect of Y and Ce in different proportions on microstructures and mechanical properties of LZ91. The microstructures and mechanical properties of as-cast and cold-rolled LZ91 alloys with Y and Ce addition were investigated. The grain size of the LZ91 was refined due to the addition of Y and Ce. Y significantly strengthened LZ91 while Ce weakened the strengthening effect of Y. The mechanical properties increased first and then decreased with the content of Y and Ce, however, it still showed a strengthening effect compared to LZ91 alloys. The addition of Y caused the formation of Mg24Y5 and Mg12ZnY. With the addition of Ce, Mg12Ce and CeZn5 formed with a continuous-network distribution. Mg-9Li-1Zn-1.5Y exhibited the most excellent microstructure and mechanical properties in as-cast state (UTS, YS, and elongation are 162 MPa, 130 MPa and 49.6%, respectively) and cold-rolled state (UTS, YS, and elongation are 255 MPa, 231 MPa and 31.9%, respectively) states because of the prominent refinement effect of Y on alpha phase and the dispersion strengthening by Mg24Y5. Meanwhile, the elongation of Mg-9Li-1Zn-1.5Ce after cold rolling was abnormally enhanced. This was explained that the coarse Mg12Ce in the as-cast state was broken into fine dispersed particles after cold rolling. This paper provides a reference for the selection and quantification of rare earth elements in duplex Mg-Li alloys. It also provides a reference way to refine large-size second phases in duplex Mg-Li alloys. (C) 2019 Elsevier B.V. All rights reserved.