Deformation behavior of Mg-Y-Ni alloys containing different volume fraction of LPSO phase during tension and compression through in-situ synchrotron diffraction  

作　　者：S.Z.Wu Y.Q.Chi G.Garces X.H.Zhou H.G.Brokmeier X.G.Qiao M.Y.Zheng 

机构地区：[1]School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China [2]School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,China [3]Department of Physical Metallurgy,CENIM-CSIC,Avenida Gregorio del Amo 8,28040 Madrid,Spain [4]Institute of Materials Science and Engineering,Clausthal University of Technology,Agricolastrasse 6,D-38678 Clausthal-Zellerfeld,Germany

出　　处：《Journal of Magnesium and Alloys》2024年第9期3631-3645,共15页镁合金学报（英文）

基　　金：supported by National Natural Science Foundation of China(no.U21A2047,no.51971076 and no.52001069).

摘　　要：The deformation behavior of the as-extruded Mg-Y-Ni alloys with different volume fraction of long period stacking ordered(LPSO)phase during tension and compression was investigated by in-situ synchrotron diffraction.The micro-yielding,macro-yielding,tension-compression asymmetry and strain hardening behavior of the alloys were explored by combining with deformation mechanisms.The micro-yielding is dominated by basal slip of dynamic recrystallized(DRXed)grains in tension,while it is dominated by extension twinning of non-dynamic recrystallized(non-DRXed)grains in compression.At macro-yielding,the non-DRXed grains are still elastic deformed in tension and the basal slip of DRXed grains in compression are activated.Meanwhile,the LPSO phase still retains elastic deformation,but can bear more load,so the higher the volume fraction of hard LPSO phase,the higher the tensile/compressive macro-yield strength of the alloys.Benefiting from the low volume fraction of the non-DRXed grains and the delay effect of LPSO andγphases on extension twinning,the as-extruded alloys exhibit excellent tension-compression symmetry.When the volume fraction of LPSO phase reaches∼50%,tension-compression asymmetry is reversed,which is due to the fact that the LPSO phase is stronger in compression than in tension.The tensile strain hardening behavior is dominated by dislocation slip,while the dominate mechanism for compressive strain hardening changes from twinning in theα-Mg grains to kinking of the LPSO phase with increasing volume fraction of LPSO phase.The activation of kinking leads to the constant compressive strain hardening rate of∼2500 MPa,which is significantly higher than the tensile strain hardening rate.

关 键 词：Mg-Y-Ni alloys LPSO phase In-situ synchrotron diffraction Micro-yielding Tensile-compression asymmetry Strain hardening 

分 类 号：TG146.22[一般工业技术—材料科学与工程]