Implementation of Balanced Strength and Toughness of VW93A Rare-Earth Magnesium Alloy with Regulating the Overlapping Structure of Lamellar LPSO Phase and β′Phase  

作　　者：Chao Wang Xi Zhao Yayun He Dingxia Zheng 

机构地区：[1]School of Aerospace Engineering,North University of China,Taiyuan,030051,China [2]School of Mechanical and Electrical Engineering,North University of China,Taiyuan,030051,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2024年第10期1735-1751,共17页金属学报（英文版）

基　　金：financially supported by the Special Project of Science and Technology Cooperation and Exchange of Shanxi Province(No.202104041101033);the special fund for Science and Technology Innovation Teams of Shanxi Province.

摘　　要：Although extensive research has been conducted on the strengthening mechanism of rare-earth magnesium alloys,achieving a balance between strength and toughness has proven challenging.This paper introduces a method for regulating the overlapping structure of the lamellar long-period stacking ordered(LPSO)phase andβ′phase to achieve a balance between strength and toughness in the alloy.By focusing on the extruded VW93A alloy cabin component,the study delves into the mechanism of the alloy's strength and toughness through a comparative analysis of the microstructure characteristics and room-temperature mechanical properties of the alloys in various states.Additionally,the molecular dynamics simulation is employed to clarify the mechanism of the alloy's strength and toughness balance induced by the overlapping structure.The findings reveal that when theβ′phase precipitates in the alloy alone,a significant increase in strength is achieved by pinning dislocations,albeit at the expense of reduced plasticity.Conversely,the presence of the lamellar LPSO phase disperses dislocations between the LPSO phase lamellae,thereby enhancing plasticity by avoiding stress concentration resulting from dislocation stacking.When both phases coexist in the alloy and form an overlapping structure,the dispersion of dislocations due to the lamellar LPSO phase weakens the pinning effect of theβ′phase,further reducing dislocation stacking and resulting in a balance of strength and toughness in the alloy.Ultimately,the alloy with the overlapping structure exhibits an ultimate tensile strength and elongation of 421 MPa and 20.1%,respectively.

关 键 词：Extrusion Rare-earth magnesium alloys Cabin component Long-period stacking ordered(LPSO)phase β'phase Molecular dynamics simulations 

分 类 号：TG146.22[一般工业技术—材料科学与工程]