Refining 18R-LPSO phase into sub-micron range by pre-kinking design and its prominent strengthening effect on Mg_(97)Y_(2)Zn_(1) alloy  

作　　者：Chao Sun Huan Liu Ziyue Xu Yuna Wu Kai Yan Jia Ju Jinghua Jiang Feng Xue Jing Bai Yunchang Xin 

机构地区：[1]College of Mechanics and Materials,Hohai University,Nanjing 210000,China [2]College of Materials Science and Engineering,Southeast University,Nanjing 211189,China [3]Jiangsu Key Laboratory for Light Metal Alloys,Nanjing Yunhai Special Metals Co.,Ltd.,Nanjing 211200,China [4]College of Mechanical Engineering,Yangzhou University,Yangzhou 225127,China [5]Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology,Nanjing Institute of Technology,Nanjing 211167,China [6]Key Laboratory for Light-weight Materials,Nanjing Tech University,Nanjing 210009,China

出　　处：《Journal of Materials Science & Technology》2024年第9期13-24,共12页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(Nos.51901068 and 52271101);the Key Research and Development Program of Jiangsu Province(No.BE2021027);the Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology(No.ASMA202102);the Jiangsu Key Laboratory for Light Metal Alloys(No.LMA202101);the Research Fund from Key Laboratory for Light-weight Materials of Jiangsu Province.

摘　　要：In this study,a composite deformation strategy of pre-kinking(equal channel angular pressing(ECAP))followed by large-ratio hot extrusion(HE)was designed to refine the 18R long period stacking ordered(LPSO)phase into sub-micron range in a Mg_(97)Y_(2)Zn_(1)(at.%)alloy.After the composite processing,the mechanical properties of the alloy are significantly enhanced,superior to the majority of reported Mg_(97)Y_(2)Zn_(1) and other LPSO-containing Mg alloys.Among the composite deformed alloys,the 16P-HE alloy exhibits the best mechanical properties with tensile yield strength(TYS)of 475 MPa,ultimate tensile strength(UTS)of 526 MPa,and fracture elongation(FE)of 14.5%.Quantitative analysis of 18R phase indicates that increasing ECAP pass from 1 to 16 gradually decreases the average size of 18R phase from 5.1μm to 2.3μm.After HE,the 18R phase is further refined with a corresponding decrease in the average size in the descending order of 1P-HE(4.3μm),4P-HE(3.2μm),and 16P-HE(1.4μm)alloys.Calculation of the strengthening contributions confirms that the superior mechanical properties of 16P-HE alloy are mainly due to its strongest interface strengthening(145 MPa)and grain boundary strengthening(189 MPa)from the sub-micron 18R phase andα-Mg grains.Moreover,the strengthening effect of 18R phase decreases gradually with their morphology changing from particles to fibers,and to blocks.The obtained results further deepen and broaden the strengthening-toughening theory of 18R phase.

关 键 词：Magnesium alloys Long period stacking ordered structure Plastic deformation Refinement Mechanical property 

分 类 号：TG13[一般工业技术—材料科学与工程]