AZ31镁合金双峰组织形成机制及其变形行为  

Formation Mechanism and Deformation Behavior of AZ31 Magnesium Alloy Bimodal Structure

作　　者：周雯慧 熊锦涛 黄思程 王鹏昊 刘勇[1] ZHOU Wenhui;XIONG Jintao;HUANG Sicheng;WANG Penghao;LIU Yong(Jiangxi Key Laboratory of Light Alloy,School of Advanced Manufacturing,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学先进制造学院轻合金材料江西省重点实验室,南昌330031

出　　处：《金属学报》2025年第3期488-498,共11页Acta Metallurgica Sinica

基　　金：国家重点研发计划项目No.2022YFC2905204;国家自然科学基金项目No.52061028;江西省重点研发专项项目No.20223-BBE51021;江西省重大科技成果熟化与工程化项目No.20243BDD40002。

摘　　要：由变形粗晶与再结晶细晶组成的双峰组织可兼顾高强度和高塑性。其中细晶能有效阻碍位错的运动,提供高强度;粗晶为累积的位错提供额外的容纳空间,提高塑性。本工作通过控制挤压工艺在AZ31镁合金中构筑双峰组织,研究了双峰组织的形成机制及其变形行为。双峰组织的形成归因于塑性变形阶段的不完全动态再结晶以及第二相粒子的激发成核效应。变形过程中,细晶承受较大的应力,而粗晶则承载更多的应变。细晶是AZ31镁合金强度显著提升的关键,粗晶的协调变形作用则为其优异的塑性提供了保障。得益于双峰组织良好的变形能力,对双峰组织AZ31镁合金进一步挤压,成功制备了细晶AZ31镁合金,合金展现出优异的力学性能:抗拉强度达到265 MPa,屈服强度为112 MPa,并保持了19%的伸长率,实现了强度与塑性的协同提升。The magnesium alloy exhibits a notable plasticity limitation due to its hcp structure.In recent years,the development of a bimodal structure,consisting of deformed coarse grains and recrystallized fine grains,has emerged as an effective strategy to balance the strength and plasticity of magnesium alloys,offering a new avenue for property.This optimization study investigates the formation mechanism and deformation behavior of the bimodal structure in Az31 magnesium alloy by controlling the extrusion process.The formation of the bimodal structure is attributed to the incomplete dynamic recrystallization during plastic deformation and the particle-stimulated nucleation effect of the secondary phase.During deformation,fine grains endure higher stresses,while coarse grains accommodate more strain.The fine grains significantly contribute to the improved strength of the Az31 magnesium alloy,while the coordi-nated deformation of the coarse grains ensures excellent plasticity.Leveraging the superior deformation capability of the bimodal structure,fine-grained Az31 magnesium alloy was successfully fabricated through further extrusion,achieving outstanding mechanical properties:a tensile strength of 265 MPa,a yield strength of 112 MPa,and an elongation of 19%.This demonstrates the synergistic enhancement of strength and plasticity.

关 键 词：变形镁合金 双峰组织 变形行为 动态再结晶机制 强塑性协同提升 

分 类 号：TG146.2[一般工业技术—材料科学与工程]