Mg-Sn Alloys Research Articles

Self-supporting Mg-Sn alloy anode for high-energy Li-ion batteries

Due to advantages such as low reaction potential, high gravimetric and volumetric capacity, and minimal structural changes during interaction with lithium, the research on Mg anodes in Li-ion batteries has garnered significant attention. However, the slow diffusion kinetics of Li in Mg limits its further advancement. In this study, we designed an ultrathin, flexible, and self-supporting Mg–Sn alloy anode featuring an interleaved two-phase distribution. The electrode was fabricated through a simple one-step magnetron sputtering method, which circumvents the need for complex procedures like slurry preparation and coating. Both theoretical calculations and experimental results indicate that the introduction of a second phase(Mg2Sn phase) significantly enhances the interaction between Mg and Li, thereby unlocking the lithium storage capabilities of Mg. The developed Mg–Sn alloy electrode demonstrates a charge specific capacity of 1,618 mAh g−1 at 50 mA g−2 and maintains a capacity of 421 mAh g−1 after 50 cycles.

Microstructure characterization and age hardening response of Mg-8Sn-2Al alloy with Bi, Ag addition

The effects of Bi and Ag addition on the microstructure and age hardening response of Mg-8Sn-2Al alloy were investigated in this study. The Mg2Sn phase distributed along grain boundaries was observed in as-cast Mg-8Sn-2Al alloys and disappeared after solution treatment due to the Sn dissolution into ɑ-Mg matrix. However, a majority of Mg2Sn phase disappeared and few Mg2Sn particles still existed in the solid solutioned Mg-8Sn-2Al alloys containing Bi element. Mg2Sn precipitates formed in all peak-aged alloys. And Al, Bi and Ag elements are enriched in the areas of lath-shaped and spherical Mg2Sn precipitates in peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy. Bi and Ag elements can act as heterogeneous nucleation sites and restrict the growth of precipitates to improve the age hardening response of Mg-8Sn-2Al alloy. Meanwhile, the undissolved Mg3Bi2 phase or early precipitated Mg3Bi2 phase during ageing treatment probably change the morphology and elements distribution of Mg2Sn precipitates. In addition, Ag and Bi atoms play a role on grain refinement and solution strengthening in Mg-8Sn-2Al alloy. Therefore, the micro-hardness value of peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy increased to 69.9 HV from 47.4 HV of solid solutioned Mg-8Sn-2Al alloy. The precipitation behaviour, refined second phase, grain refinement and solute atoms synergistically made contributions to the strength improvement. The roles of Bi and Ag elements on improving age hardening response and precipitates characteristics are discussed in this study, which provides an important reference for exploring aged Mg-Sn alloys.

Effect of Precipitates on Dynamic Recrystallization and Texture of Mg-Sn Alloy Under Different Strain Rates

Effect of Precipitates on Dynamic Recrystallization and Texture of Mg-Sn Alloy Under Different Strain Rates

The quantitative regulation of basal and prismatic Mg2Sn to strengthen Mg-Sn alloys

The continuous network of prismatic and basal precipitates in Magnesium (Mg) based alloys can improve the strength to the largest extent, even better than the prismatic one. This work constructed basal-prismatic Mg2Sn phases in varying proportions to investigate the impact of different proportions of basal or prismatic phases on the mechanical properties of Mg-5 wt% Sn alloy. The finding revealed that a combined process of twinning, first aging, de-twinning and second aging (T-A1-DT-A2) can generate dual-precipitates in both basal and prismatic planes in the interior of the same grain regions. By regulating the first and second aging procedures, it is possible to acquire specific proportional basal or prismatic Mg2Sn in Mg-Sn alloys. The strength and toughness of Mg-Sn alloy containing dual-precipitates in both basal and prismatic planes are simultaneously enhanced. Especially, the tensile and compressive yield strength (TYS and CYS), tensile and compressive ultimate strength (UTS and UCS) of Mg-Sn alloy with basal-prismatic Mg2Sn can reach 217 MPa, 163 MPa, 318 MPa and 441 MPa, compared to the sample with basal phase, which is improved by 149.4 %, 108.9 %, 82.7 % and 50.5 %, respectively. The sample with the sample first and second aging time (T-A15-DT-A15) shows more excellent comprehensive mechanical properties at room temperature. High strength might be attributed to the dislocation strengthening (26 MPa), fine grain strengthening (4.5 MPa) and precipitate orientation strengthening (102 MPa).

Investigating the Synergistic Impact of Cenosphere and Mg-Sn Alloy on the Tribological and Mechanical Properties of Aluminum Foam Composites

Investigating the Synergistic Impact of Cenosphere and Mg-Sn Alloy on the Tribological and Mechanical Properties of Aluminum Foam Composites

Enhanced Thermoelectric Performance of Mg-Sn Thin Films: Role of Mg9Sn5 Phase and One-Dimensional Electronic Structure.

Mg-Sn alloy thin films have garnered significant attention for their outstanding thermoelectric (TE) properties and cost-effective elemental composition, making them potential candidates for wearable energy harvesting devices. While previous studies have explored the properties of these thin films, limited research has been conducted to identify physical factors that can further enhance their performance. In this study, we present a novel approach utilizing a convenient electron beam coevaporation technique to fabricate Mg-Sn alloy thin films. Experimental results revealed that controlling the tin content in the Mg-Sn thin films at 38.9% led to the formation of a mixed-phase structure, comprising Mg2Sn and Mg9Sn5. This dual-phase structure exhibited a notable advantage in enhancing the TE performance. The presence of the Mg9Sn5 phase significantly increased the carrier concentration, while maintaining the original Seebeck coefficient and mobility, thereby improving the conductivity of Mg2Sn. Theoretical calculations indicated that the Mg9Sn5 phase displayed 1D-like characteristics, leading to a highly effective valley degeneracy and consequently a high power factor. Overall, this work introduces a promising approach to fabricate high-performance Mg-Sn alloy thin films through electron beam coevaporation, opening up possibilities for their application in wearable energy harvesting devices.

Effect of Mn and Ca on mechanical, corrosion and surface roughness of Mg-5Sn alloy

Magnesium and its alloys have an extensive application prospect in the aerospace, automotive industry, sports equipment, biomedical and energy storage due to their high specific strength and low density compared with iron and Aluminum alloys. However, the strength and the corrosion resistance of Mg alloys is still the major drawback that hampers their application. Alloying is generally used to improve mechanical and corrosion properties. The mg-Sn alloy system was extensively studied and the Mg-5Sn alloy was chosen as the base composition owing to the addition of 5 wt% Sn improves the strength and corrosion resistance of pure Mg. The present work aims to investigate the effect of Mn and Ca addition on mechanical, corrosion and roughness properties of as-cast Mg-5Sn-Mn-Ca alloy. The addition of Mn and Ca elements significantly refined α-Mg grains. Mn-rich phase precipitated alongside intermetallic eutectic Mg2Snphases and CaMgSn eutectics observed on the grain boundaries. The strength, hardness, roughness, and corrosion resistance of Mg-5Sn alloy are observed to be improved by the addition of Mn and Ca.

An Experimental Survey of Anodically Enhanced Cathodic Kinetics of Magnesium Alloys

The anodically enhanced cathodic kinetics behavior of 18 different Mg alloys encompassing high-purity Mg, Mg-Al, Mg-Zn, Mg-Sn, and Mg-RE (RE = rare earth element)-based alloys was studied via global and local electrochemical methods in unbuffered 0.6 M NaCl. The total cathodic enhancement observed for Mg-Al and Mg-Sn alloys was found to decrease with increasing primary alloy content, whereas the cathodic activity of Mg-Zn-based alloys increased with alloying content. Furthermore, a lower fraction of secondary phases expressed as a volume fraction present generally led to lower susceptibility toward anodically enhanced cathodic kinetics. The variations in enhanced cathodic activity were attributed to the identity of the primary alloying element, microstructure, and nature of the dissolution product film.

Fundamentals of liquid metal displacement reactions: Emf measurements of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn

The driving force of spontaneous displacement reactions between Na-Sn alloys and molten LiCl, MgCl2, and CaCl2 salts stems from the difference of chemical potential between Na and Li, Mg, or Ca in liquid Sn. However, fundamental thermodynamic data are absent. Herein, electromotive force (emf) values of Na-Sn, Li-Sn, Mg-Sn, and Ca-Sn alloys (electrodeposition of Na, Li, Mg, and Ca in liquid Sn via the coulometric titration) were measured in NaF-NaCl-NaI, LiF-LiCl, MgCl2-NaCl-KCl, and CaCl2-LiCl-NaCl salts respectively at 650 °C. The measured emf values of these alloys were normalized with respect to the Cl−/Cl2 potential that −3.14 V to −3.35 V for Na-Sn (mole fractions xNa = 0.02–0.30) alloy, −2.90 V to −3.21 V for Li-Sn (xLi = 0.02–0.30) alloy, −2.38 V to −2.45 V for Mg-Sn (xMg = 0.01–0.15) alloy, and −2.90 V to −3.06 V for Ca-Sn (xCa = 0.01–0.15) alloy. And Li20Sn, Mg10Sn, and Ca10Sn alloys were successful prepared by displacement reactions between Na20Sn alloys and LiCl-NaCl, MgCl2-NaCl, and CaCl2-NaCl salts, which offers theoretical guidelines for s-block elements extraction and separation.

Evolution of precipitate orientation and its effect on thermal conductivity of Mg-5Sn alloy

The evolution of precipitate orientation and its effect on the thermal conductivity of Mg-5Sn alloys under different treatments were systematically investigated. The results show that for the alloy subjected to aging prior to twinning (Sample AT), the basal precipitates are precisely regulated to be the prismatic precipitates, and the lath-shaped precipitates experience a rigid rotation of 3.7° to accommodate the twinning shear. For hexagon-shaped precipitates with a larger thickness in Sample AT, the precipitate only experiences a small rigid rotation of 0.2°, due to the development of stacking faults releasing part of the strain at the precipitate/twin interface. In addition, the orientation of precipitates has a significant effect on the thermal conductivity of the alloy. When the measurement direction of thermal conductivity is parallel to extrusion direction (ED), the precipitates lying on the basal plane, perpendicular to ED, are more beneficial to the improvement of thermal conductivity than precipitates lying on the prismatic plane parallel to ED. Sample TA (aging after twinning) with precipitates lying on the basal plane shows the best thermal conductivity of 137.81 W/(m·K).

Improving mechanical properties of Mg-Sn alloys by co-addition of Li and Al

In this work, a novel low-alloyed Mg-Sn-Li-Al alloy with high-strength has been developed. The addition of ∼1 ​wt% Li into the Mg-2Sn wt.% binary alloy can change the type of strengthening phases in Mg-2Sn-1Li sample (TL21), involving the formation of both Li2MgSn and Mg2Sn phases. The co-addition of ∼1 ​wt% Al and ∼1 ​wt% Li can further induce the higher density of both micron-sized phases and nano-precipitations in the Mg-2Sn-1Li-1Al sample (TLA211). The nano-precipitations can inhibit the grain growth, which thus lead to the fine grain size of ∼1.38 ​μm in TLA211 sample, and ∼1.59 ​μm in the TL21 sample. Besides, the profuse nano-phases would improve the yield strength via Orowan hardening effect. Consequently, the TL21 sample can exhibit the high yield strength of ∼204 ​MPa, and elongation of ∼6.6%. The TLA211 sample exhibits the much higher yield strength of ∼250 ​MPa, ultimate tensile strength of ∼291 ​MPa, and also high elongation of ∼9.0%. The high strength-ductility synergy, together with the low-Sn content, make the present Mg-Sn based alloy to be potential for the wider industrial applications.

Machine learning based corrosion prediction of as cast Mg-Sn alloys for biomedical applications

Magnesium and its various alloys are the promising materials for orthopedic implant applications because of its light weight, biocompatible and biodegradable characteristics. The prediction of corrosion rate is important when the implant material is present in the human body for longer time period and it can be done by machine learning approach. Corrosion data of Mg-Sn alloy samples were collected and fit in to the machine learning algorithm. Extreme Gradient Boost model has given the best output for the prediction of corrosion behavior with the accuracy of R2 value of 0.961 in EIS plots and 0.6145 in Tafel plots.

Corrosion behavior of Mg-1Sn anode for primary Magnesium batteries

Mg alloys are promising materials for a variety of applications such as automobile, aerospace biomedical and energy storage, etc. Mg-1Sn alloys can be used as the anode for battery application. The corrosion characteristics of Mg-1Sn (wt. %) alloy are analyzed by electrochemical tests like Galvanostatic Electrochemical impedance spectroscopy (EIS), and Tafel slope. Mg-x Sn (1 wt. %) alloys as an anode is newly fabricated using stir and squeeze cast technique for the research. This study analyzed and compared the corrosion behavior of Mg-1Sn (wt. %) alloys in 3.5 wt. % NaCl solution with different immersion periods. An immersion test of Mg-Sn alloy was performed to access the corrosion rate by immersing the samples in NaCl Solution for the short duration of 60 minutes [ST] and 24 hours. Mg-1Sn (wt. %) alloy immersed for 24 hours in NaCl solution showed the better electrochemical performance compared to the sample immersed for 60 minutes (Rp[24 h] > Rp[ST], Icorr[24 h] < Icorr[ST], CR[24h] < CR[ST]). The improvement in the corrosion properties of Mg1Sn alloy under 24h of immersion is attributed to the formation of a protective oxide layer, thereby suppressing the transfer of chloride ions from the electrolyte solution.

INVESTIGATION OF THE STRAIN RATE SENSITIVITY OF Mg-6Sn AND Mg-6Sn-3Y ALLOYS

This study reports the influence of the addition of Yttrium (wt.3%) on strain-rate sensitivity of Mg-6Sn alloy. The Mg-6Sn and Mg-6Sn-3Y alloys were made by using high pressure die-cast. The microstructural and X-ray diffraction results exhibited that the Sn3Y5 and MgSnY intermetallic phases were formed with addition of Y to the Mg-6Sn alloy. Furthermore, the grain structure of the Mg-6Sn alloy was changed from dendritic to globular with addition of Y. The strain-rate sensitivity value of the Mg-6Sn-3Y alloy is found higher than that of the Mg-6Sn alloy for all strain value. This result was attributed to the formation of new intermetallics (Sn3Y5 and MgSnY) and microstructure morphology (from dendritic structure to globular).

Unexpected effect of pre-aging prior to extrusion on microstructure and mechanical properties of extruded Mg–8Sn–6Zn–0.1Mn alloy

Pre-aging prior to extrusion (AE), aiming to achieve high strength without sacrificing ductility, has shown considerable potential in Mg-Sn alloys containing low content of Zn element. For Mg–8Sn–6Zn–0.1Mn alloy containing high contents of Sn and Zn elements, however, an unexpected decrease in mechanical properties after AE treatment is observed and comprehensively investigated in this paper. We demonstrate that after pre-aging treatment, the size and volume fraction of bulk Mg2Sn particles are not decreased as expected, but some fine particles are segregated around the bulk Mg2Sn phases due to high contents of Sn and Zn in this alloy. The bulk phases are prone to facilitate the occurrence of particle-stimulated nucleation and continuous dynamic recrystallization mechanisms during extrusion. Since pre-aging treatments produce a high number of fine particles, these particles exert a pinning or drag effect on grain boundaries, inhibiting the nucleation of dynamic recrystallization, which reduce the volume fraction of dynamic recrystallized grains (DRXed). Unexpectedly, solution-extruded (SE) alloy has finer and higher volume fraction of DRXed grains than AE alloy. Additionally, the fine particles produced by dynamic precipitation in SE alloy are densely distributed and smaller than those in AE alloy. The coarse particles in AE alloy serve as the crack initiation sites under external force, and reduce the ductility of the alloy. Consequently, SE alloy with excellent strength-ductility synergy can be attributed to a combination of refinement of grain structure and fine densely distributed particles.

Effect of Ca and Zr Additions on Microstructure and Mechanical Properties of As-Extruded Mg-3Sn Alloy.

In this paper, the effect of Ca and Zr additions on microstructure and mechanical properties at room temperature of Mg-Sn alloys was investigated by comparison of Mg-3Sn (wt.%) (T3), Mg-3Sn-1Ca (wt.%) (TX31), and Mg-3Sn-1Ca-1Zr (wt.%) (TXK311) alloys under extrusion. The results show that the main phases of as-extruded T3 alloy were α-Mg and Mg2Sn phases, while the CaMgSn phase was formed and the precipitation of Mg2Sn phase was inhibited in the TX31 and TXK311 alloys due to the addition of the Ca element. Zr did not form intermetallic compounds with other elements but dissolved in the grains of the matrix and became nucleating particles. Incomplete dynamic recrystallization (DRX) occurred in all alloys during hot extrusion. The coarse rod-like and fine block-like mixed CaMgSn phase was observed in α-Mg matrix of as-extruded samples of the TX31 alloy, and the dispersed granular CaMgSn phase was observed in the TXK311 alloy. Ca inhibited the dynamic recrystallization behavior of the alloys, while Zr promoted the dynamic recrystallization behavior. All the as-extruded alloys exhibit typical fiber texture of {0001} basal//ED. With the addition of Ca and Zr elements, the particle stimulated nucleation (PSN) effect excited by the second phase particles gradually weakened the texture. TXK311 alloy has good comprehensive mechanical properties at room temperature, with tensile strength, yield strength, and elongation of 261 MPa, 244 MPa, and 11%, respectively, and the average grain size was 1.8 μm. Grain refinement and second phase dispersion strengthening are considered to play critical roles in the strength optimization of the TXK311 alloy.

Insights of Microstructural Features and Their Effect on Degradation and the In Vitro Bioactivity Response of as-Cast Mg-Sn Alloys for Orthopedic Implant Applications.

The present work focuses on a deep understanding of microstructural evolution and phase formation in a binary Mg-Sn alloy system. Mg-xSn (x = 1, 5, 10 wt.%) alloys were cast using a squeeze casting technique. Phase identification and microstructural analysis were done using XRD (X-ray Diffraction) and FESEM with EDS (Field Emission Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy), respectively. The mechanical behavior of the alloys under study was evaluated by conducting a compression test. The corrosion behavior of all the alloys were intricately studied using electrochemical corrosion tests and an immersion test in the simulated body fluid (SBF) environment for different immersion periods. The bioactivity response of Mg-Sn alloys systems under this study was investigated by immersing the samples in SBF for 14 days. From the analysis of the results, it was understood that the amount of Sn addition has a large influence on the metallurgical, corrosion, and bioactivity properties. Interesting facts about the intermetallic phase formation and segregation of Sn were observed when the wt.% of Sn was varied in the alloy and the evolution of the microstructure was described clearly. Mechanical properties of Mg-Sn alloys were improved, as the Sn content increased up to 5 wt.% and declined in the case of a 10 wt.% Sn addition. A similar trend was observed even in the case of corrosion resistance and bioactivity properties. Among the alloy compositions studied, Mg with a 5 wt.% addition has proved to be a promising candidate material for orthopedic implant applications with an acceptable elastic modulus, higher corrosion resistance, and an excellent bioactive response.

Effect of Hot Rolling on the Microstructure and Mechanical Performance of a Mg-5Sn Alloy.

A Mg-5Sn alloy was hot rolled at 380 °C with three different rolling reductions (30%, 50%, and 70%), and its effect on the microstructure and mechanical performance was examined. Grain size decreases, whereas the area fraction of Mg2Sn particles and dislocation density increase with the increase in rolling reduction. Therefore, the yield strength (YS) and ultimate tensile strength (UTS) exhibit an ascending trend, whereas the elongation (EL) shows a descending trend with increasing rolling reduction. The alloy hot rolled for 70% possesses a high strength of 310 MPa and an EL of 8.4%. The strength enhancement is mainly ascribed to precipitation strengthening, grain refinement strengthening, and dislocation strengthening.

Achieving advanced elevated-temperature strength by tailoring precipitates in Mg-Sn-Y alloys

The Mg-Sn-Y alloys exhibiting advanced elevated-temperature strength up to 300 ℃ were newly developed by tailoring precipitates through partially substituting and increasing yttrium (Y) (2, 3.5 wt%) for tin (Sn) in Mg-2.5Sn alloy. The effects of precipitates on the room/elevated-temperature mechanical properties, and the related dynamic precipitation behavior were investigated. The elevated-temperature strengthening mechanism of the alloy was revealed. The precipitates transformed from Mg2Sn in Mg-Sn alloy to Sn3Y5 in Mg-Sn-Y alloys. The abundant Sn3Y5 nanoparticles formed in the as-extruded Mg-0.5Sn-3.5Y alloy which exhibited significant higher peak strength as 223 MPa compared to that of Mg-2.5Sn as 53 MPa. The calculation of the critical nucleation energy for dynamic precipitation indicated that the Mg-Sn-Y alloys exhibited a smaller nucleation barrier for dynamic precipitation of dense nanoscale Sn3Y5 particles compared to the Mg-Sn alloy. This barrier was further decreased with increasing Y content, as exemplified by the increased area fraction of nanoparticles in the Mg-0.5Sn-3.5Y alloy. The abundant Sn3Y5 nanoparticles can inhibit the grain boundary crack propagation, and the formed fine grains (~3.8 µm) can effectively hinder the dislocation motion. Therefore, the present work demonstrated that coupling a high area fraction of thermally stable nanoparticles with grain refinement can provide an effective approach to acquire superior elevated-temperature strength for Mg alloys.

Precipitation strengthening in Mg-Sn alloys with multiple precipitate types

ABSTRACT Peak-aged Mg-6Sn, Mg-6Sn-3Al and Mg-6Sn-3Zn (wt.%) alloys have been characterised mechanically using micro-pillar compression and microstructurally using TEM. These alloys contain more than one type of precipitate. A modified Orowan equation is proposed to quantify the strengthening behaviour of the containing multiple precipitate types. The as-estimated values agree adequately with the experimental results.