Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a cat...Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a category of novel{1010}_(α) prismatic platelets has replaced thoroughly the traditionalβ’precipitate formed in magnesium rare earth(Mg-RE)alloys.Herein,the microstructural characteristics of platelet are investigated particularly by atomic scale scanning transmission electron microscopy.It is confirmed that the platelet has a Mg_(2) InSm composition and can maintain a coherent relationship with α-Mg matrix.Importantly,on account of the similarities between In and Mg atoms,the Mg_(2) InSm prismatic platelet could be structurally categorized as a generalizedβ"precipitate with a(Mg_(2) In)Sm-type DO_(19) structure when both In and Mg are regarded as an equivalent atom.Thus,the addition of In into Mg-Sm alloy induces the formation ofβ"precipitate.Furthermore,the formedβ"prismatic platelets generally have a large average aspect ratio.The findings are of great significance to construct the effective precipitation strengthening phases and optimize the microstructure of Mg-based alloys.展开更多
基金financially supported by the Liaoning Provincial Natural Science Foundation of China(No.2020-MS-085)。
文摘Prismatic precipitate platelet is always purposefully designed in the microstructure of magnesium alloys due to its greater contribution to yield stress.In this study,with an introduction of In into Mg-Sm system,a category of novel{1010}_(α) prismatic platelets has replaced thoroughly the traditionalβ’precipitate formed in magnesium rare earth(Mg-RE)alloys.Herein,the microstructural characteristics of platelet are investigated particularly by atomic scale scanning transmission electron microscopy.It is confirmed that the platelet has a Mg_(2) InSm composition and can maintain a coherent relationship with α-Mg matrix.Importantly,on account of the similarities between In and Mg atoms,the Mg_(2) InSm prismatic platelet could be structurally categorized as a generalizedβ"precipitate with a(Mg_(2) In)Sm-type DO_(19) structure when both In and Mg are regarded as an equivalent atom.Thus,the addition of In into Mg-Sm alloy induces the formation ofβ"precipitate.Furthermore,the formedβ"prismatic platelets generally have a large average aspect ratio.The findings are of great significance to construct the effective precipitation strengthening phases and optimize the microstructure of Mg-based alloys.
