This study investigated the influence of aging prior to extrusion(APE)on the tensile strength and ductility of as-extruded Mg-8.32Sn-1.85Zn-0.17Mn alloy.Results demonstrated that APE treatment dramatically increased t...This study investigated the influence of aging prior to extrusion(APE)on the tensile strength and ductility of as-extruded Mg-8.32Sn-1.85Zn-0.17Mn alloy.Results demonstrated that APE treatment dramatically increased the volume fraction of recrystallized grains,thereby decreasing the grain size of the as-extruded alloy.This phenomenon was primarily attributed to the particle-stimulated nucleation and pinning effect induced by large amounts of small Mg 2 Sn precipitates produced by the APE treatment and dynamic precipitation.The tensile yield strength increased from 242.4 MPa to 256.5 MPa after APE treatment.The improved tensile strength can be attributed to the enhanced grain boundary strengthening and precipitation strengthening.The ductility of the as-extruded alloy also markedly increased from 7.1%to 13.5%after the APE treatment.The improved ductility of APE alloy was attributed to the texture randomization,the activity of pyramidal<c+a>slip and the suppressed formation of{10-11}contraction twins and coarse Mg 2 Sn phases.展开更多
The effect of extrusion ratio on microstructure and mechanical properties of as-extruded Mg-6Sn-2Zn-1Ca （TZX621）（mass fraction, %） alloy was investigated. It is found that incomplete dynamic recrystallization （DR...The effect of extrusion ratio on microstructure and mechanical properties of as-extruded Mg-6Sn-2Zn-1Ca （TZX621）（mass fraction, %） alloy was investigated. It is found that incomplete dynamic recrystallization （DRX） took place in as-extrudedTZX621 alloy. As the extrusion ratio was increased from 6 to 16, both fraction of un-DRXed grains and average size of DRXedgrains in as-extruded TZX621 alloy decreased and the basal texture was weakened. Coarse CaMgSn phase was broken into particlesand fine Mg2Sn phase precipitated from α-Mg matrix during hot extrusion. Yield strength, ultimate tensile strength and elongation ofas-extruded TZX621 alloy with extrusion ratio of 16 reached 226.9 MPa, 295.6 MPa and 18.1%, which were improved by 36.0%,17.7% and 13.5%, respectively, compared to those of as-extruded TZX621 alloy with extrusion ratio of 6.展开更多
The hot deformation behavior of a fine-grained Mg–8 Sn–2 Zn–2 Al(TZA822, in wt%) alloy was investigated in the temperature range of 150–350°C and the strain rate of 0.01–10 s^-1 employing thermomechanical si...The hot deformation behavior of a fine-grained Mg–8 Sn–2 Zn–2 Al(TZA822, in wt%) alloy was investigated in the temperature range of 150–350°C and the strain rate of 0.01–10 s^-1 employing thermomechanical simulator. In most of the cases, the material showed typical dynamic recrystallization(DRX) features i.e., a signal peak value followed by a gradual decrease or to reach a steady state. The work hardening rate was found to increase with decreasing temperature and increasing strain rate, while strain rates had great effects on work hardening behavior. Meanwhile, the constitutive analysis indicated that cross-slip of dislocations was likely to be the dominant deformation mechanism. In addition, the processing map at the strain of 0.1–0.7 showed two stability domains with high power dissipation efficiencies and the optimum hot working parameters for the studied alloy was determined to be 350°C/0.01 s^-1 and 350°C/10 s^-1, at which continuous DRX(CDRX) and discontinuous DRX(DDRX) as main softening mechanism. The instability regions occurred at 200–250°C/10 s^-1 and the main flow instability mechanism was twinning and/or flow localization bands, which were prone to induce cracks and caused in-consistent mechanical properties of the alloy.展开更多
As-cast Mg-Sn alloys(3,6,and 9 wt%Sn)were solution treated at 653,703 and 753 K(380,430 and 480℃)for 1,4,8,12 and 24 h to determine the variation of secondary phase with respect to Sn content,temperature and time.Mg-...As-cast Mg-Sn alloys(3,6,and 9 wt%Sn)were solution treated at 653,703 and 753 K(380,430 and 480℃)for 1,4,8,12 and 24 h to determine the variation of secondary phase with respect to Sn content,temperature and time.Mg-3 wt%Sn exhibits Mg2Sn dissolution at all solution treatment temperatures whereas Mg-6 and 9 wt%Sn alloy displays Mg2Sn reprecipitation and dissolution depending on the heat treatment temperature.In addition,a combined mathematical model that predicts the secondary phase dissolution and solute redistribution as a function of temperature and time is presented in this work.This model is a significant improvement compared to the previous studies where the dissolution and homogenization processes are considered independently.The effect of grain size and solute mobility upon the dissolution and homogenization kinetics is discussed as well.展开更多
The Mg–8Sn–4Zn–2Al（TZA842, in wt%） alloys with different initial microstructure（as-cast-AC and homogenization treatment-HT） subjected to hot extrusion. Also, the strengthening responses to AC and HT for the ext...The Mg–8Sn–4Zn–2Al（TZA842, in wt%） alloys with different initial microstructure（as-cast-AC and homogenization treatment-HT） subjected to hot extrusion. Also, the strengthening responses to AC and HT for the extruded TZA842 alloys were reported. The results revealed that the alloy subjected to HT shows finer grain size, more homogenous microstructure and weaker basal texture than those of counterpart subjected to AC. In addition, compared with TZA842-AC alloy, precipitates were finer and uniformly dispersed in TZA842-HT owing to the utilization of HT. Moreover, the TZA842-HT alloy showed higher yield strength of 200 MPa, ultimate tensile strength of 290 MPa and elongation（EL） of17.9% than those of TZA842-AC, which was mainly attributed to the combined effects of grain boundary strengthening,precipitation strengthening, solid solution strengthening and weak texture. Strengthening mechanism for both alloys was discussed in detail.展开更多
The microstructure and mechanical properties of Mg-xSn （x-3, 7 and 14, mass fraction, %） alloys extruded indirectly at 300 ℃ were investigated by means of optical microscopy, scanning electron microscopy and tensil...The microstructure and mechanical properties of Mg-xSn （x-3, 7 and 14, mass fraction, %） alloys extruded indirectly at 300 ℃ were investigated by means of optical microscopy, scanning electron microscopy and tensile test. The grain size of the a-Mg matrix decreases from 220, 160 and 93 μm after the homogenization treatment to 28, 3 and 16 μm in the three alloys after extrusion, respectively. The results show that the grain refinement is most remarkable in the as-extruded Mg-7Sn alloy. At the same time, the amount of the Mg2Sn particles remarkably increases in the Mg-7Sn alloy with very uniform distribution in the a-Mg matrix. In contrast, the Mg2Sn phase inherited from the solidification with a large size is mainly distributed along grain boundary in the Mg-14Sn alloy. The tensile tests at room temperature show that the ultimate tensile strength of the as-extruded Mg-7Sn alloy is the highest, i.e., 255 MPa, increased by 120% as compared with that of as-cast samples.展开更多
The major interface betweenβ-Mg_(3)Sn precipitate plate and theα-Mg matrix in a Mg-9.8wt.%alloy has been investigated using aberrationcorrected scanning transmission electron microscopy and first-principles calculat...The major interface betweenβ-Mg_(3)Sn precipitate plate and theα-Mg matrix in a Mg-9.8wt.%alloy has been investigated using aberrationcorrected scanning transmission electron microscopy and first-principles calculations.It is found that Sn atoms orderly distribute in the single layer of theα-Mg matrix immediately adjacent to the broad surface ofβat the early stage of ageing.These Sn atoms substitute Mg atoms located at the centers of equilateral triangles constituted by three Mg columns in the outmost layer ofβ.First-principles calculations suggest that the ordered Sn distribution is energetically favored and it not only decreases the interfacial energy of theβ-matrix interface but also hinders the occurrence of 1/3<01■0>αshear that thickens theβplate.展开更多
Aberration-corrected scanning transmission electron microscopy has been used to study a novel metastable phase,designated asβ’’phase,induced to form by electron beam irradiation in a Mg-9.8 wt.%Sn alloy.This phase ...Aberration-corrected scanning transmission electron microscopy has been used to study a novel metastable phase,designated asβ’’phase,induced to form by electron beam irradiation in a Mg-9.8 wt.%Sn alloy.This phase is spherical in three dimensions,having a D019 structure with the lattice parameters of a=0.642 nm,c=0.521 nm and space group of P63/mmc.Its chemical formula is Mg_(3)Sn,like theβ’metastable precipitate phase.The orientation relationship between theβ’’phase and theα-Mg matrix is such that■_(β)’’//■_(α)and(0001)_(β)’’//(0001)_(α).Its formation involves solely the ordering of Sn atoms in the solid solution magnesium matrix.First-principles calculations indicate that the formation of theβ’’phase is energetically favored.展开更多
Mg-Sn-Ca alloys promise a reasonable corrosion resistance in combination with good creep resistance, likely due to the presence of Ca2-xMgxSn and other phases. The selected alloys with 3% Sn and Ca in the range of 1%-...Mg-Sn-Ca alloys promise a reasonable corrosion resistance in combination with good creep resistance, likely due to the presence of Ca2-xMgxSn and other phases. The selected alloys with 3% Sn and Ca in the range of 1%-2% have been extruded in order to achieve more homogeneous microstructure compared with the as-cast alloys. Optical microscopy(OM) and X-ray diffraction(XRD) techniques were used to study the microstructure and phases of these alloys. The corrosion behavior of these alloys was investigated by means of salt spray test and potentio-dynamic measurements. The results obtained on the alloys Mg-3Sn (T3), Mg-3Sn-1Ca (TX31), and Mg-3Sn-2Ca (TX32) indicate the presence of the same phases in as-cast and after extrusion, namely Mg2Sn, Ca2-xMgxSn, and Ca2-xMgxSn/Mg2Ca, respectively. However, due to the occurrence of extensive recrystallization in the extrusion process, the grain size has significantly reduced after extrusion. The reduction leads to the improvement of the corrosion resistance after extrusion which is then comparable with the commercial alloy AZ91D.展开更多
The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as...The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as well as a change in the category of second phase from CaMgSn to(Ca,Ce)Mg Sn and Mg12Ce.The volume fraction of second phase increased with rising Ce content,which aggravated the restriction of DRXed grain growth during the extrusion process and eventually led to texture weakening of as-extruded Mg-Sn-Ca based alloys.In terms of plasticity,owing to vigorously activated basal slip and homogeneous distributed tensile strain in tension,the tensile ductility of as-extruded alloys reached the maximum value of 27.6%after adding 0.2 wt%Ce,which enhanced by about 26%than that of ternary MgSn-Ca alloy.However,further Ce additions(0.5 and 1.0 wt%)would coarsen the second phase particles and then impair ductility.The tension-compression yield asymmetry of as-extruded Mg-Sn-Ca ternary alloy was alleviated greatly via Ce additions,due to the joint effects of grain refinement,increased amount of strip distributed second phase particles and texture weakening.展开更多
The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-1Mn alloy were investigated and compared by using optical and electron microscopies, X-ray diffraction analysis, ...The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-1Mn alloy were investigated and compared by using optical and electron microscopies, X-ray diffraction analysis, and tensile and creep tests. The results indicated that the microstructure of the Mg-3Sn-1Mn alloy with the addition of 0.87 wt.%Ce was refined while the microstructures of the alloys with the additions of 0.79 wt.%Y or 0.84 wt.%Gd were coarsened. Furthermore, adding 0.87 wt.%Ce to the Mg-3Sn-1Mn alloy could improve the tensile properties while adding 0.79 wt.%Y or 0.84 wt.%Gd gave a detrimental effects on the tensile properties. In addition, adding 0.87 wt.%Ce, 0.79 wt.%Y and 0.84 wt.%Gd to the Mg-3Sn-1Mn alloy could improve the creep properties. Among the three additions, the addition of 0.87 wt.%Ce was more suitable to further improve the strength and creep performance of the Mg-3Sn-1Mn alloy.展开更多
基金The authors are grateful for the financial supports from the Sichuan Science and Technology Program(2019YJ0478)the Research Foundation for the introduction of talent of Sichuan University of Science and Engineering,China(Grant Nos.2017RCL18 and 2017RCL35)the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province,China(Grant Nos.2017CL05,2017CL06 and 2018CL06)。
文摘This study investigated the influence of aging prior to extrusion(APE)on the tensile strength and ductility of as-extruded Mg-8.32Sn-1.85Zn-0.17Mn alloy.Results demonstrated that APE treatment dramatically increased the volume fraction of recrystallized grains,thereby decreasing the grain size of the as-extruded alloy.This phenomenon was primarily attributed to the particle-stimulated nucleation and pinning effect induced by large amounts of small Mg 2 Sn precipitates produced by the APE treatment and dynamic precipitation.The tensile yield strength increased from 242.4 MPa to 256.5 MPa after APE treatment.The improved tensile strength can be attributed to the enhanced grain boundary strengthening and precipitation strengthening.The ductility of the as-extruded alloy also markedly increased from 7.1%to 13.5%after the APE treatment.The improved ductility of APE alloy was attributed to the texture randomization,the activity of pyramidal<c+a>slip and the suppressed formation of{10-11}contraction twins and coarse Mg 2 Sn phases.
基金Project(51601076)supported by the National Natural Science Foundation of ChinaProjects(16KJB430013,17KJA430005)supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,China
文摘The effect of extrusion ratio on microstructure and mechanical properties of as-extruded Mg-6Sn-2Zn-1Ca （TZX621）（mass fraction, %） alloy was investigated. It is found that incomplete dynamic recrystallization （DRX） took place in as-extrudedTZX621 alloy. As the extrusion ratio was increased from 6 to 16, both fraction of un-DRXed grains and average size of DRXedgrains in as-extruded TZX621 alloy decreased and the basal texture was weakened. Coarse CaMgSn phase was broken into particlesand fine Mg2Sn phase precipitated from α-Mg matrix during hot extrusion. Yield strength, ultimate tensile strength and elongation ofas-extruded TZX621 alloy with extrusion ratio of 16 reached 226.9 MPa, 295.6 MPa and 18.1%, which were improved by 36.0%,17.7% and 13.5%, respectively, compared to those of as-extruded TZX621 alloy with extrusion ratio of 6.
基金financially supported by the National Natural Science Foundation of China(Nos.51404166,51704209 and51701060)the Shanxi Scholarship Council of China(No.2014-023)+4 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2014017)the Shanxi Province Science Foundation for Youths(No.2016021063)the Natural Science Foundation of Hebei Province(No.E2016202130)the Research Foundation from Education Department of Hebei(No.QN2015035)the Outstanding Youth Scholar Science and Technology Innovation Program of Hebei University of Technology(No.2015002)
文摘The hot deformation behavior of a fine-grained Mg–8 Sn–2 Zn–2 Al(TZA822, in wt%) alloy was investigated in the temperature range of 150–350°C and the strain rate of 0.01–10 s^-1 employing thermomechanical simulator. In most of the cases, the material showed typical dynamic recrystallization(DRX) features i.e., a signal peak value followed by a gradual decrease or to reach a steady state. The work hardening rate was found to increase with decreasing temperature and increasing strain rate, while strain rates had great effects on work hardening behavior. Meanwhile, the constitutive analysis indicated that cross-slip of dislocations was likely to be the dominant deformation mechanism. In addition, the processing map at the strain of 0.1–0.7 showed two stability domains with high power dissipation efficiencies and the optimum hot working parameters for the studied alloy was determined to be 350°C/0.01 s^-1 and 350°C/10 s^-1, at which continuous DRX(CDRX) and discontinuous DRX(DDRX) as main softening mechanism. The instability regions occurred at 200–250°C/10 s^-1 and the main flow instability mechanism was twinning and/or flow localization bands, which were prone to induce cracks and caused in-consistent mechanical properties of the alloy.
文摘As-cast Mg-Sn alloys(3,6,and 9 wt%Sn)were solution treated at 653,703 and 753 K(380,430 and 480℃)for 1,4,8,12 and 24 h to determine the variation of secondary phase with respect to Sn content,temperature and time.Mg-3 wt%Sn exhibits Mg2Sn dissolution at all solution treatment temperatures whereas Mg-6 and 9 wt%Sn alloy displays Mg2Sn reprecipitation and dissolution depending on the heat treatment temperature.In addition,a combined mathematical model that predicts the secondary phase dissolution and solute redistribution as a function of temperature and time is presented in this work.This model is a significant improvement compared to the previous studies where the dissolution and homogenization processes are considered independently.The effect of grain size and solute mobility upon the dissolution and homogenization kinetics is discussed as well.
基金financially supported by the National Natural Science Foundation of China (Grant No. 51404166)a Research Project Supported by Shanxi Scholarship Council of China (Grant No. 2014-023)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (Grant No. 2014017)
文摘The Mg–8Sn–4Zn–2Al（TZA842, in wt%） alloys with different initial microstructure（as-cast-AC and homogenization treatment-HT） subjected to hot extrusion. Also, the strengthening responses to AC and HT for the extruded TZA842 alloys were reported. The results revealed that the alloy subjected to HT shows finer grain size, more homogenous microstructure and weaker basal texture than those of counterpart subjected to AC. In addition, compared with TZA842-AC alloy, precipitates were finer and uniformly dispersed in TZA842-HT owing to the utilization of HT. Moreover, the TZA842-HT alloy showed higher yield strength of 200 MPa, ultimate tensile strength of 290 MPa and elongation（EL） of17.9% than those of TZA842-AC, which was mainly attributed to the combined effects of grain boundary strengthening,precipitation strengthening, solid solution strengthening and weak texture. Strengthening mechanism for both alloys was discussed in detail.
基金Project(2008S089)supported by the Key Laboratory Program of Liaoning Province,ChinaProject(2007010303025)supported by the Shenyang Talents Supporting,ChinaProject(50731002)supported by the National Natural Science Foundation of China
文摘The microstructure and mechanical properties of Mg-xSn （x-3, 7 and 14, mass fraction, %） alloys extruded indirectly at 300 ℃ were investigated by means of optical microscopy, scanning electron microscopy and tensile test. The grain size of the a-Mg matrix decreases from 220, 160 and 93 μm after the homogenization treatment to 28, 3 and 16 μm in the three alloys after extrusion, respectively. The results show that the grain refinement is most remarkable in the as-extruded Mg-7Sn alloy. At the same time, the amount of the Mg2Sn particles remarkably increases in the Mg-7Sn alloy with very uniform distribution in the a-Mg matrix. In contrast, the Mg2Sn phase inherited from the solidification with a large size is mainly distributed along grain boundary in the Mg-14Sn alloy. The tensile tests at room temperature show that the ultimate tensile strength of the as-extruded Mg-7Sn alloy is the highest, i.e., 255 MPa, increased by 120% as compared with that of as-cast samples.
基金financially National Natural Science Foundation of China(52101167 and 52071033)Natural Science Foundation Project of CQ(cstc2020jcyjmsxm X0832)+3 种基金the Fundamental Research Funds for the Central Universities(2020CDJ-LHZZ-085)State Key Laboratory of Powder Metallurgy,Central South University,Changsha,Chinasupported in part by the High Performance Computing center of the Central South UniversityJFN acknowledges the support from the Australian Research Council and computational resources provided by the Australian Government through Pawsey under the National Computational Merit Allocation Scheme and the use of the National Computational Infrastructure。
文摘The major interface betweenβ-Mg_(3)Sn precipitate plate and theα-Mg matrix in a Mg-9.8wt.%alloy has been investigated using aberrationcorrected scanning transmission electron microscopy and first-principles calculations.It is found that Sn atoms orderly distribute in the single layer of theα-Mg matrix immediately adjacent to the broad surface ofβat the early stage of ageing.These Sn atoms substitute Mg atoms located at the centers of equilateral triangles constituted by three Mg columns in the outmost layer ofβ.First-principles calculations suggest that the ordered Sn distribution is energetically favored and it not only decreases the interfacial energy of theβ-matrix interface but also hinders the occurrence of 1/3<01■0>αshear that thickens theβplate.
基金financially supported by National Natural Science Foundation of China(51771036 and 51421001)。
文摘Aberration-corrected scanning transmission electron microscopy has been used to study a novel metastable phase,designated asβ’’phase,induced to form by electron beam irradiation in a Mg-9.8 wt.%Sn alloy.This phase is spherical in three dimensions,having a D019 structure with the lattice parameters of a=0.642 nm,c=0.521 nm and space group of P63/mmc.Its chemical formula is Mg_(3)Sn,like theβ’metastable precipitate phase.The orientation relationship between theβ’’phase and theα-Mg matrix is such that■_(β)’’//■_(α)and(0001)_(β)’’//(0001)_(α).Its formation involves solely the ordering of Sn atoms in the solid solution magnesium matrix.First-principles calculations indicate that the formation of theβ’’phase is energetically favored.
文摘Mg-Sn-Ca alloys promise a reasonable corrosion resistance in combination with good creep resistance, likely due to the presence of Ca2-xMgxSn and other phases. The selected alloys with 3% Sn and Ca in the range of 1%-2% have been extruded in order to achieve more homogeneous microstructure compared with the as-cast alloys. Optical microscopy(OM) and X-ray diffraction(XRD) techniques were used to study the microstructure and phases of these alloys. The corrosion behavior of these alloys was investigated by means of salt spray test and potentio-dynamic measurements. The results obtained on the alloys Mg-3Sn (T3), Mg-3Sn-1Ca (TX31), and Mg-3Sn-2Ca (TX32) indicate the presence of the same phases in as-cast and after extrusion, namely Mg2Sn, Ca2-xMgxSn, and Ca2-xMgxSn/Mg2Ca, respectively. However, due to the occurrence of extensive recrystallization in the extrusion process, the grain size has significantly reduced after extrusion. The reduction leads to the improvement of the corrosion resistance after extrusion which is then comparable with the commercial alloy AZ91D.
基金financially supported by the Chongqing Science and Technology Commission(Nos.cstc2017zdcy-zdzxX0006,cstc2017jcyjAX0012 and cstc2018jcyjAX0472)the National Natural Science Foundation of China(Nos.51531002 and U1764253)+3 种基金the National Key Research and Development Program of China(Nos.2016YFB0301104 and 2016YFB0101700)the Chongqing Scientific&Technological Talents Program(No.KJXX2017002)the China Postdoctoral Science Foundation(No.2018T110948)the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJQN201801306).
文摘The microstructure and mechanical properties of Mg-Sn-Ca-Ce alloys with different Ce contents(0.0,0.2,0.5,1.0 wt%)were studied at room temperature.Ce additions to ternary Mg-Sn-Ca alloy resulted in grain refinement as well as a change in the category of second phase from CaMgSn to(Ca,Ce)Mg Sn and Mg12Ce.The volume fraction of second phase increased with rising Ce content,which aggravated the restriction of DRXed grain growth during the extrusion process and eventually led to texture weakening of as-extruded Mg-Sn-Ca based alloys.In terms of plasticity,owing to vigorously activated basal slip and homogeneous distributed tensile strain in tension,the tensile ductility of as-extruded alloys reached the maximum value of 27.6%after adding 0.2 wt%Ce,which enhanced by about 26%than that of ternary MgSn-Ca alloy.However,further Ce additions(0.5 and 1.0 wt%)would coarsen the second phase particles and then impair ductility.The tension-compression yield asymmetry of as-extruded Mg-Sn-Ca ternary alloy was alleviated greatly via Ce additions,due to the joint effects of grain refinement,increased amount of strip distributed second phase particles and texture weakening.
基金Project supported by the National Natural Science Foundation of China (50725413), the National Basic Research Program of China (973) (2007CB613704)the Chongqing Science and Technology Program of China (2010AC4085, 2009AB4134 and 2006AA4012-9-6)the Pro-gram for Hundreds of Distinguished Leading Scientists of CQ CSTC (2010CSTC-HDLS)
文摘The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-1Mn alloy were investigated and compared by using optical and electron microscopies, X-ray diffraction analysis, and tensile and creep tests. The results indicated that the microstructure of the Mg-3Sn-1Mn alloy with the addition of 0.87 wt.%Ce was refined while the microstructures of the alloys with the additions of 0.79 wt.%Y or 0.84 wt.%Gd were coarsened. Furthermore, adding 0.87 wt.%Ce to the Mg-3Sn-1Mn alloy could improve the tensile properties while adding 0.79 wt.%Y or 0.84 wt.%Gd gave a detrimental effects on the tensile properties. In addition, adding 0.87 wt.%Ce, 0.79 wt.%Y and 0.84 wt.%Gd to the Mg-3Sn-1Mn alloy could improve the creep properties. Among the three additions, the addition of 0.87 wt.%Ce was more suitable to further improve the strength and creep performance of the Mg-3Sn-1Mn alloy.
