Microstructure and Mechanical Properties of As-casted Mg-10Gd-2Y-1Zn Magnesium Alloy with Different Mn Contents AITranslate
Abstract AITranslate
At present，magnesium alloys containing Mn are mostly used for deformed magnesium alloys，and there are few studies and applications in cast magnesium alloys. The as-cast microstructure of the alloy is the basis of the deformation microstructure，which has an important impact on the subsequent deformation and the microstructure after deformation，which is worthy of in-depth study. This study systematically discussed the influence mechanism of manganese （Mn）content （0%，0.3%，0.6%，and 0.9%）on the microstructure and mechanical properties of cast Mg-10Gd-2Y-1Zn magnesium alloy. The effects of Mn on the phase composition，grain size，second phase precipitation behavior，and mechanical properties of the alloy were systematically analyzed by X-ray diffraction （XRD），optical microscopy （OM），scanning electron microscopy （SEM），transmission electron microscopy （TEM），and tensile test at room temperature. Experimental results showed that the as-cast alloy was mainly composed of α-Mg matrix，Mgs（Gd，Y）eutectic phase，and long-period stacking ordered phase （LPSO，chemical formula Mg12（GdY）Zn）. The aging states were dominated by α-Mg，LPSO，and Gd+Y cubic phases. The addition of Mn did not change the phase type but was mainly distributed as nanoscale α-Mn particles （20-100 nm）in the matrix and grain boundaries，with minor Mn segregation at grain boundaries，leading to reduced plasticity. XRD did not detect a peak of Mn-containing compounds，confirming that Mn did not form a new phase with the Mg matrix. At 0.6%Mn，grain refinement was the best，with average size decreasing from （532±48）to （312±34）μm. The mechanisms were as follows： Mn decreased the solute concentration of Gd/Y in the solid phase，promoting their segregation in the liquid phase and increasing the amount of precipitation in the second phase； Mn increased the solute partition coefficient of Gd/Y，enhancing growth inhibition； Mn enrichment at the solid-liquid interface front during solidification hindered grain growth. Excess Mn （0.9%）caused α-Mn aggregation and grain coarsening to （392±39）μm. The area fraction of the second phase in as-cast/aging state increased with the increase of Mn. Appropriate Mn （≤0.6%）refined the eutectic web and promoted the precipitation of LPSO phase （XRD peak strength increased）. EDS showed that Mn replaced part of the Zn in the LPSO phase，and the strain field induced by α-Mn particles accelerated the formation of 14H-LPSO. When Mn was excessive （0.9%），the second phase was coarsened，weakening Zener pinning and the grain refinement. The strength of the aging alloy first increased and then decreased. At 0.6% Mn，performance peaked. Tensile strength （UTS）was （272±9）MPa，which was 20 MPa higher than that of Mn alloy. Yield strength （YS）was （171±5）MPa，which was increased by 28 MPa. Elongation （EL）was inhibited by the brittle phase of α-Mn and the segregation of grain boundaries，and the overall elongation remained low. UTS dropped to 258 MPa with 0.9%Mn. Finally，Mn significantly refined the grains and improved the strength of Mg-10Gd-2Y-1Zn alloy by regulating the Gd/Y solute partition and the precipitation of the second phase，but excessive addition leaded to phase coarsening and grain boundary segregation，resulting in performance deterioration. This study provided a theoretical basis for the rational application of Mn in high-strength and toughness cast magnesium alloys.
KeyWords AITranslate
［1］（张小翠. 热挤压态Mg-10Gd-4Y-0.5Zr合金的时效析出［J］. 锻压技术， 2024， 49（2）： 241.）
X C Zhang. Aging precipitation of Mg-10Gd-4Y-0.5Zr alloy in hot extrusion state［J］. Forging & Stamping Technology， 2024， 49（2）： 241.
［2］（庞松， 华溪如， 陶静雅， 季松， 龚政轩， 王堃， 候正全， 戴铮， 陈斌， 肖旅. Mg-Gd系铸造镁合金时效析出相研究现状及展望［J］. 铸造工程， 2023， 47（1）： 1.）
S Pang， X R Hua， J Y Tao， S Ji， Z X Gong， K Wang， Z Q Hou， Z Dai， B Chen， L Xiao. Research status and prospect of aging precipitation phase of MG-GD cast magnesium alloys［J］. Casting Engineering， 2023， 47（1）： 1.
［3］（田学栋， 赵熹， 任贤魏， 王思琪， 张治民， 郭拉凤. 调控LPSO层片相Mg-9Gd-4Y-2Zn-0.5Zr合金的热变形行为及热塑性提升机制［J］. 塑性工程学报， 2023， 30（3）： 131.）
X D Tian， X Zhao， X W Ren， S Q Wang， Z M Zhang， L F Guo. Hot deformation behavior and thermoplastic lifting mechanism of Mg-9Gd-4Y-2Zn-0.5Zr alloy for regulating LPSO lamellar phase［J］. Journal of Plasticity Engineering， 2023， 30（3）： 131.
［4］Ding Z B， Zhao Y H， Lu R P， Yuan M N， Wang Z J， Li H J， Hou H. Effect of Zn addition on microstructure and mechanical properties of cast Mg-Gd-Y-Zr alloys［J］. Transactions of Nonferrous Metals Society of China， 2019， 29（4）： 722.
［5］Cao P， Qian M， Stjohn D H. Effect of manganese on grain refinement of Mg-Al based alloys［J］. Scripta Materialia， 2006， 54（11）： 1853.
［6］Wang Y， Rong W， Wu Y J， Peng J. Effects of Mn addition on the microstructures and mechanical properties of the Mg-15Gd-1Zn alloy［J］. Journal of Alloys and Compounds， 2017， 698： 1066.
［7］（喻正文. Mg-Mn系合金显微组织及力学性能的研究［D］. 重庆： 重庆大学， 2015.1.）
Z W Yu. Study on Microstructure and Mechanical Properties of Mg-Mn Alloys［D］. Chongqing： Chongqing University， 2015.1.
［8］（聂中奎， 古东懂， 杨宗全， 高攀， 陶健全， 彭建. Gd对Mg-xGd-0.8Mn镁合金组织和耐蚀性能的影响［J］. 稀有金属， 2024， 48（4）： 457.）
Z K Nie， D D Gu， Z Q Yang， P Gao， J Q Tao， J Peng. Microstructure and corrosion resistance of Mg-xGd-0.8Mn magnesium alloy by Gd addition［J］. Chinese Journal of Rare Metals， 2024， 48（4）： 457.
［9］Liu Z Y， Chen B， Zhao P Y， Yu L P， Pei Z R， Zhou B J， Hao Y Q， Zhou N， Zeng X Q. Atomic-scale characterization of the precipitates in a Mg-Gd-Y-Zn-Mn alloy using scanning transmission electron microscopy［J］. Vacuum， 2023， 207： 111668.
［10］（王奎. Mg-Gd-Y-Zn-Mn高强韧镁合金均质制备及其塑性变形与强韧化机理研究［D］. 重庆： 重庆大学， 2020.1.）
K Wang. Homogenization Preparation of Mg-Gd-Y-Zn-Mn High-Strength and Toughness Magnesium Alloy and Its Plastic Deformation and Toughening Mechanism［D］. Chongqing： Chongqing University， 2020.1.
［11］（薛丹月. 超高强Mg-Gd-Y-Zn-Mn合金组织性能调控及服役性能研究［D］. 重庆： 重庆大学， 2019.1.）
D Y Xue. Study on Microstructure and Performance Control and Service Performance of Ultra-High-Strength Mg-Gd-Y-Zn-Mn Alloy［D］. Chongqing： Chongqing University， 2019.1.
［12］（谢飞舟. 高强度Mg-Gd-Y-Zn-Mn合金锻造工艺研究［D］. 重庆： 重庆大学， 2016.1.）
F Z Xie. Study on Forging Process of High-Strength Mg-Gd-Y-Zn-Mn Alloy［D］. Chongqing： Chongqing University， 2016.1.
［13］Wang Y， Rong W， Wu Y J， Peng L M， Chen J， Ding W J. Effects of Mn addition on the microstructures and mechanical properties of the Mg-15Gd-1Zn alloy［J］. Journal of Alloys and Compounds， 2017， 698： 1066.
［14］（张丁非， 石国梁， 赵霞兵， 齐福刚. Mn元素在Mg-Zn-Mn合金中演变形式和作用的研究［J］. 材料导报， 2011， 25（18）： 1.）
D F Zhang， G L Shi， X B Zhao， F G Qi. Study on the evolution and role of Mn in Mg-Zn-Mn alloy［J］. Materials Reports， 2011， 25（18）： 1.
［15］（姜水淼， 明开胜， 郑士建. 晶界偏析以及界面相和纳米晶材料力学性能的调控［J］. 材料研究学报， 2023， 37（5）： 321.）
S M Jiang， K S Ming， S J Zheng. Grain boundary segregation and control of interfacial phases and mechanical properties of nanocrystalline materials［J］. Journal of Materials Research， 2023， 37（5）： 321.
［16］Cheng R J， Pan F S， Jiang S， Li C， Jiang B， Jiang X Q. Effect of Sr addition on the grain refinement of AZ31 magnesium alloys［J］. Progress in Natural Science： Materials International， 2013， 23（1）： 7.
［17］Han Q Y. The role of solutes in grain refinement of hypoeutectic magnesium and aluminum alloys［J］. Journal of Magnesium and Alloys， 2022， 10（7）： 1846.
［18］Qian M， Stjohn D H. Grain nucleation and formation in Mg-Zr alloys［J］. International Journal of Cast Metals Research， 2013， 22（1-4）： 256.
［19］Li D， Zhang J S， Que Z P， Xu C X， Niu X F. Effects of Mn on the microstructure andmechanical properties of long period stacking ordered Mg95Zn2.5Y2.5 alloy［J］. Materials Letters， 2013， 109： 46.
［20］（夏子寒. Mg-Mn合金的显微组织与室温高塑性研究［D］. 哈尔滨： 哈尔滨工业大学， 2020.1.）
Z H Xia. Study on the Microstructure and Room Temperature High Plasticity of Mg Mn Alloy［D］. Harbin： Harbin Institute of Technology， 2020.1.
［21］（于艳梅， 吕衣礼， 张振忠， 杨根仓， Karma A， Beckermann C. 相场法凝固组织模拟的研究进展［J］. 铸造， 2000， （9）： 507.）
Y M Yu， Y L Lv， Z Z Zhang， G C Yang， A Karma， C Beckermann. Research progress on coagulation microstructure simulation by phase field method［J］. Casting， 2000， （9）： 507.
［22］（李俊杰， 王锦程， 杨根仓. 含第二相颗粒的晶粒长大过程相场法［J］. 稀有金属材料与工程， 2008， （10）： 1746.）
J J Li， J C Wang， G C Yang. Phase field method for grain growth process with second phase particles［J］. Rare Metal Materials and Engineering， 2008， （10）： 1746.
Basic Information:
DOI：10.13373/j.cnki.cjrm.XY23110028
Chinese Library Classification Number:TG146.22
Citation Information:
At present，magnesium alloys containing Mn are mostly used for deformed magnesium alloys，and there are few studies and applications in cast magnesium alloys. The as-cast microstructure of the alloy is the basis of the deformation microstructure，which has an important impact on the subsequent deformation and the microstructure after deformation，which is worthy of in-depth study. This study systematically discussed the influence mechanism of manganese （Mn）content （0%，0.3%，0.6%，and 0.9%）on the microstructure and mechanical properties of cast Mg-10Gd-2Y-1Zn magnesium alloy. The effects of Mn on the phase composition，grain size，second phase precipitation behavior，and mechanical properties of the alloy were systematically analyzed by X-ray diffraction （XRD），optical microscopy （OM），scanning electron microscopy （SEM），transmission electron microscopy （TEM），and tensile test at room temperature. Experimental results showed that the as-cast alloy was mainly composed of α-Mg matrix，Mgs（Gd，Y）eutectic phase，and long-period stacking ordered phase （LPSO，chemical formula Mg12（GdY）Zn）. The aging states were dominated by α-Mg，LPSO，and Gd+Y cubic phases. The addition of Mn did not change the phase type but was mainly distributed as nanoscale α-Mn particles （20-100 nm）in the matrix and grain boundaries，with minor Mn segregation at grain boundaries，leading to reduced plasticity. XRD did not detect a peak of Mn-containing compounds，confirming that Mn did not form a new phase with the Mg matrix. At 0.6%Mn，grain refinement was the best，with average size decreasing from （532±48）to （312±34）μm. The mechanisms were as follows： Mn decreased the solute concentration of Gd/Y in the solid phase，promoting their segregation in the liquid phase and increasing the amount of precipitation in the second phase； Mn increased the solute partition coefficient of Gd/Y，enhancing growth inhibition； Mn enrichment at the solid-liquid interface front during solidification hindered grain growth. Excess Mn （0.9%）caused α-Mn aggregation and grain coarsening to （392±39）μm. The area fraction of the second phase in as-cast/aging state increased with the increase of Mn. Appropriate Mn （≤0.6%）refined the eutectic web and promoted the precipitation of LPSO phase （XRD peak strength increased）. EDS showed that Mn replaced part of the Zn in the LPSO phase，and the strain field induced by α-Mn particles accelerated the formation of 14H-LPSO. When Mn was excessive （0.9%），the second phase was coarsened，weakening Zener pinning and the grain refinement. The strength of the aging alloy first increased and then decreased. At 0.6% Mn，performance peaked. Tensile strength （UTS）was （272±9）MPa，which was 20 MPa higher than that of Mn alloy. Yield strength （YS）was （171±5）MPa，which was increased by 28 MPa. Elongation （EL）was inhibited by the brittle phase of α-Mn and the segregation of grain boundaries，and the overall elongation remained low. UTS dropped to 258 MPa with 0.9%Mn. Finally，Mn significantly refined the grains and improved the strength of Mg-10Gd-2Y-1Zn alloy by regulating the Gd/Y solute partition and the precipitation of the second phase，but excessive addition leaded to phase coarsening and grain boundary segregation，resulting in performance deterioration. This study provided a theoretical basis for the rational application of Mn in high-strength and toughness cast magnesium alloys.
quote
| GB/T 7714-2015 | [1] Lirui Liu, Renju Cheng, Haijun Wang, et al. Microstructure and Mechanical Properties of As-casted Mg-10Gd-2Y-1Zn Magnesium Alloy with Different Mn Contents[J]. Chinese Journal of Rare Metals, 2025, 49(9): 1306-1316. DOI:10.13373/j.cnki.cjrm.XY23110028. |
| MLA | [1] Lirui Liu, et al., "Microstructure and Mechanical Properties of As-casted Mg-10Gd-2Y-1Zn Magnesium Alloy with Different Mn Contents." Chinese Journal of Rare Metals, vol. 49, no. 9, 2025, pp. 1306-1316, https://doi.org/10.13373/j.cnki.cjrm.XY23110028. |
| APA | [1] Lirui Liu, Renju Cheng, Haijun Wang, Daiyi Deng, Xia Wu, & Haie Zhu. (2025). Microstructure and Mechanical Properties of As-casted Mg-10Gd-2Y-1Zn Magnesium Alloy with Different Mn Contents. Chinese Journal of Rare Metals, 49(9), 1306-1316. https://doi.org/10.13373/j.cnki.cjrm.XY23110028 |
| IEEE | [1] Lirui Liu, Renju Cheng, Haijun Wang, Daiyi Deng, Xia Wu, and Haie Zhu, "Microstructure and Mechanical Properties of As-casted Mg-10Gd-2Y-1Zn Magnesium Alloy with Different Mn Contents," Chinese Journal of Rare Metals, vol. 49, no. 9, pp. 1306-1316, 2025, doi: 10.13373/j.cnki.cjrm.XY23110028. keywords: {magnesium alloy;Mn element;Mg-Gd-Y alloy;mechanical properties;microscopic structure} |