Phase equilibria and microstructure investigation of Mg-Gd-Y-Zn alloy system  

作　　者：Janet M.Meier Jiashi Miao Song-Mao Liang Jun Zhu Chuan Zhang Josh Caris Alan A.Luo 

机构地区：[1]Department of Materials Science and Engineering,The Ohio State University,Columbus,OH 43210,USA [2]CompuTherm LLC,Middleton,WI 53562 USA [3]Terves LLC,Euclid,OH 44117,USA [4]Department of Integrated Systems Engineering,The Ohio State University,Columbus,OH 43210,USA

出　　处：《Journal of Magnesium and Alloys》2022年第3期746-755,共10页镁合金学报（英文）

基　　金：partially funded by the Army Research Laboratory (ARL) and Terves LLC;supported by the Army Contracting Command - Adelphi, MD under Contract No W911QX-18-P-0038

摘　　要：In order to develop high strength Mg-Gd-Y-Zn alloys,key experiments coupled with CALPHAD(CALculation of PHAse Diagrams)calculations were carried out in the current work to provide critical understanding of this important alloy system.Three Mg-10 Gd-xY-yZn(x=4 or 5,y=3 or 5,wt.%) were mapped on Mg-Gd-Y-Zn phase diagrams for phase equilibria and microstructure investigation.Electron microscopy was performed for phase identification and phase fraction determination in as-cast and solution treated conditions.In all three alloys,the major phases were Mg-matrix and long period stacking order(LPSO) 14 H phase.With ST at 400 and 500℃,the phase fraction of LPSO 14 H increased,particularly the fine lamellar morphology in the Mg matrix.The as-cast and 400℃ Mg10 Gd5 Y3 Zn samples had Mg(Gd,Y) present.At 500℃,Mg(Gd,Y) is not stable and transforms into LPSO 14 H.The Mg 10 Gd5 Y5 Zn alloy included the WPhase,which showed a reduction in phase fraction with solution treatment.These experimental results were used to validate and improve the thermodynamic database of the Mg-Gd-Y-Zn system.Thermodynamic calculations using the improved database can well describe the available experimental results and make accurate predictions to guide the development of promising high-strength Mg-Gd-Y-Zn alloys.

关 键 词：Long period stacking order(LPSO) MICROSTRUCTURE Magnesium alloys CALPHAD Alloy development. 

分 类 号：TG146.22[一般工业技术—材料科学与工程]