退火温度对大变形终轧Mg-Zn-Zr-Nd合金显微组织和力学性能的影响

Effect of annealing temperature on microstructure and mechanical properties of Mg-Zn-Zr-Nd alloy with large final rolling deformation

张锦海 ¹聂凯波 ¹张晋华 ¹邓坤坤 ¹刘志龙²

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作者信息

1. College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China
2. State Key Laboratory of High-end Compressor and System Technology,Hefei 230031,China
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摘要

本文对Mg-3Zn-0.5Zr-χNd(χ=0,0.6)合金进行50%的大变形终轧,研究了退火温度对其组织与性能的影响.研究结果表明,轧制态Mg-3Zn-0.5Zr-0.6Nd合金抗拉强度达到386 MPa、屈服强度达到361 MPa、伸长率达到7.1%.经不同温度退火后,两种合金的强度均有所降低,而伸长率显著增加.Mg-3Zn-0.5Zr-0.6Nd合金经200℃退火后得到最优的综合力学性能:抗拉强度达到287 MPa、屈服强度达到235 MPa、伸长率达到26.1%.轧制态合金内部存在大量的变形组织、孪晶以及析出相,阻碍其室温变形,导致合金在室温拉伸过程中加工硬化率提高.经退火处理之后,合金内部的变形组织和孪晶大部分被消除,形成细小的等轴晶粒,且析出相的数量进一步增加.这导致退火态合金在室温拉伸过程中的加工硬化效应降低,动态回复效应增加,从而显著提高合金的伸长率.此外,对比Mg-3Zn-0.5Zr合金与Mg-3Zn-0.5Zr-0.6Nd合金发现,Nd元素的加入能够提高合金退火后的再结晶程度,减小基面滑移和柱面滑移系统之间的Schmid因子差,促进多系滑移的启动,有利于改善合金的塑性.

Abstract

In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was investigated.The rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both alloys.Optimal mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening rate.After annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the alloy.Additionally,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.

关键词

Mg-Zn-Zr-Nd合金/大变形终轧/退火温度/显微组织/力学性能

Key words

Mg-Zn-Zr-Nd alloy/large final rolling deformation/annealing temperatures/microstructures/mechanical properties

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基金项目

Fundamental Research Program of Shanxi Province,China(202203021221088)

Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province,China(20230010)

Shanxi Provincial Science and Technology Major Special Project Plan of Taking the Lead in Unveiling the List,China(202201050201012)

Research Project Supported by Shanxi Scholarship Council of China(2023-063)

National Natural Science Foundation of China(51771129)

National Natural Science Foundation of China(52271109)

National Key Research and Development Program for Young Scientists,China(2021YFB3703300)

Special Fund Project for Guiding Local Science and Technology Development by the Central Government,China(YDZJSX2021B019)

Open Foundation of State Key Laboratory of Highend Compressor and System Technology,China(SKL-YSJ202103)

出版年

2024

中南大学学报(英文版)

中南大学

中南大学学报(英文版)

CSTPCDEI

影响因子：0.47

ISSN：2095-2899

参考文献量9

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