Microalloying Additions Research Articles

Enhancing strength and γ’-coarsening resistance through micro-alloying additions to an oxidation resistant Al-Co-Cr-Fe-Ni-Ti compositionally complex alloy

The effect of alloying additions of Mo and Ta (0.4at.% each) on the microstructure, mechanical properties, oxidation resistance and coarsening resistance of the L12-strengthened (γ’) Al-rich Ni51Co18Fe5Cr10Al12Ti4 alloy was determined. The micro-alloyed composition exhibited improved yield strength (from room temperature to 1000 °C) and coarsening resistance (enhanced by 33% at 800 °C) compared to the base Ni51Co18Fe5Cr10Al12Ti4 alloy. The present Al-rich alloy compositions (both the micro-alloyed and reference compositions) exhibited superior oxidation resistance (800-1000 °C) compared to a Ti-rich Ni51Co18Fe5Cr10Al8Ti8 alloy (with similar precipitate volume fraction and (Al+Ti)-content) and commercial Inconel 718. The present work highlights the promise of Al-rich γ’-strengthened Al-Co-Cr-Fe-Ni-Ti alloys as candidates for high-performance, high-temperature structural materials, characterised by an attractive blend of strength, resistance to coarsening, and resilience against oxidation.

Effects of Ag/Sc microadditions on the precipitation of over-aged Al–Zn–Mg–Cu alloys

Microalloying addition plays a significant role in controlling the characteristics of precipitates in Al alloys. This study investigates the effects of Ag and Sc microalloying addition on the thermal stability of Al–Zn–Mg–Cu alloys, via differential scanning calorimetry, transmission electron microscopy, and atom-probe tomography. The results demonstrate that Ag and Sc additions increase the number density of η-MgZn2 type nano-precipitates (formed during heat treatment) by forming direct (Mg–Ag phase, prototype of precipitate) or indirect precursors (Al2Sc phase, constituent of precipitate) for the precipitate. In addition, the Ag and Sc elements can effectively prevent the coarsening of η precipitates and facilitate the high-density distribution of fine η precipitates, during the over-aging period, improving the thermal stability of the Al–Zn–Mg–Cu alloys. The thermal stability is particularly improved by Ag addition because Ag atoms directly prevent the coarsening of η precipitates by hindering Zn diffusion into the precipitate. On the contrary, Sc addition indirectly prevents the coarsening of η precipitates by depleting the solute species from the Al matrix, enabling abundant precipitates limited growth. Thus Ag addition improves precipitation strengthening by preventing the coarsening of precipitates during over-aging.

Correlation of microstructure with thermal and tensile creep properties of novel Sn-5Sb-0.5Cu alloy reinforced with Co particles for soldering applications

The present research examined how cobalt microalloying additions of 0.25, 0.5, 0.75, and 1 weight percent affected the microstructural properties, thermal features, and tensile creep characteristics of eutectic Sn-5 wt% Sb- 0.5 wt% Cu (SSC) lead-free solder alloy. According to the results, cobalt additions of 0.25, 0.5, and 0.75 wt% did not affect SbSn phase but significantly refined β-Sn grains, facilitating the formation of fine fibers (Cu,Co)6Sn5 together with plate-like CoSn3 phases, and preventing the formation of Cu6Sn5 phases. Furthermore, a large amount of cobalt (1 wt%) addition accumulated in the coarsening of the CoSn3 phase. Additions of 0.25 wt% Co, 0.75 wt% Co, and 1 wt% Co did not affect the melting temperatures, but pasty ranges had been slightly lowered, which may enhance the thermal characteristics. Addition of 0.5 wt% Co had unfavorable effects on both melting point and pasty range. This has significant effects on solder reliability and electronic service performance. In terms of creep behavior, the SSC-0.75 wt% Co specimens displayed the highest creep resistance because of the fine dispersion of intermetallic compounds (IMCs) and extended the creep-rupture life to a level that is 3.0 times greater than the SSC baseline. Lower creep resistance was observed in SSC-0.25 wt% Co specimens, which was mostly due to the smaller volume fraction of the precipitate phases and the absence of the CoSn3 phase. Depending on the determined stress exponents and activation energies, it is suggested that the dominant deformation mechanism in SSC-xCo solders is the dislocation climb controlled by short-circuit pipe diffusion across the whole temperature range that was examined.

Effect of austenitisation and tempering treatments on the mechanical properties of advanced high strength spring steel SAE 9254

In response to increasingly stringent global regulations within the automotive industry, there is a growing demand for lightweight yet high-strength steel suspension coil springs. This study undertakes a comprehensive examination of the critical factors influencing the mechanical properties of SAE 9254, a well-established spring material, in its quenched and tempered (QT) state. The primary objective is to optimise its strength and ductility, especially in high-performance applications with an emphasis on lightweight design. The investigation encompasses a detailed exploration of the effects of varying austenitisation temperature (AT) and austenitisation time (At) on the microstructure and mechanical properties of the steel. Of particular interest is the study of tempering temperatures ranging between 300°C and 350°C to elucidate the mechanisms responsible for enhancing the steel's strength. Notably, the findings highlight dislocation density as the primary factor driving the strengthening of martensitic spring steel. Furthermore, the pivotal role of austenite grain size before quenching becomes evident, influencing toughness, ductility, martensite block size, and the percentage of retained austenite (γR). This study provides valuable insights into optimising the mechanical properties of SAE 9254 spring steel for high-performance applications, achieving ultimate tensile strengths (UTS) exceeding 2100 MPa and a reduction in area (RoA) exceeding 30%. Notably, the properties attained for this grade are comparable to those achieved with microalloying additions. Consequently, this research underscores the significance of controlling austenite grain size and dislocation density as critical factors for tailoring the properties of martensitic steels, positioning them as competitive materials, particularly in the pursuit of lightweight design.

Enhancing properties of Al-Zn-Mg-Cu alloy through microalloying and heat treatment

This paper aims to understand the influence of microalloying constituents (Ti, Zr, Sr and Sc), and three heat treatment conditions i.e., T6, retrogression and reaging (RRA) and high temperature aging (HTA) on mechanical and thermal characteristics of modified Al-Zn-Mg-Cu-X alloy using microstructural analyses consist of precipitation characteristics, phase fraction and phase morphology. Addition of 0.25 wt % Sc significantly refines the grain structure, reducing the grain size from 62 μm to 34 μm and increasing Al3Zr, Al3(Zr, Ti), and Al3(Sc, Zr) precipitate fraction. After T6 aging, the alloy exhibits primary precipitates of fine η and T phases, accompanied by secondary intermetallics as well as S phases. RRA treatment led to a slightly larger fraction of coarse Zn and Cu-rich phases, while HTA results in larger η, T, and S phases due to high-temperature aging. The addition of Sc reduces the cooling rate by raising the transition temperature to 532 °C with an enthalpy of 22.1 J/g. T6 treatment shows dissolution of most η phases within the matrix, although RRA and HTA exhibit higher enthalpy due to a greater fraction of η phases. The tensile strength of Al-Zn-Mg-Cu-X alloy follows the following sequence: T6 > RRA > HTA > as-cast condition, regardless of micro-alloy additions. Under T6 conditions, Sc added alloy achieves 30 % higher strength, i.e., 575 MPa, than base alloy due to fine dispersoids. RRA treatment enhances elongation without compromising mechanical properties, resulting in a shift from transgranular brittle fracture to intergranular-dominated mix-mode fracture, with the presence of secondary cracking.

First-principles investigation of the effect of interfacial compositions on the formation energies of Ω′ and T1 structures

The formation energies of the structures of Ω′ and T1 precipitates having different interfacial compositions are calculated by density functional theory. Our results show that the precipitates become much more energetically favourable to form when Ag and Mg and/or Li are present at their top and bottom layers. In such interfacial configurations, the role that Ag (with an atomic size similar to that of Al) plays is dominated by the chemical bonding effect, while the ability of larger atoms of Mg and Li to reduce the formation energy of the structure of Ω′ or T1 is mainly attributable to the elastic strain reduction. The findings of the effect of interfacial composition on the formation energies of the structures of Ω′ and T1 precipitates provide an insightful understanding on how to enhance the formation a specific strengthening constituent via micro-alloying addition of appropriate elements.

Microstructural, thermal and mechanical properties of Co added Sn–0.7Cu lead-free solder alloy

This study investigated the effects of cobalt microalloying addition on the microstructural features, thermal characteristics and mechanical behavior of eutectic Sn–0.7wt%Cu lead-free solder alloys. The results show that minor cobalt addition of ~ 0.05 wt% causes significant grain refinement of β-Sn, facilitates the formation of fine fibers (Cu,Co)6Sn5 phases and preventing the formation of η′-Cu6Sn5 phases, whereas a large amount of Co (~ 0.5 wt%) additions accumulated in the (Cu,Co)6Sn5 IMCs and clearly changed into coarse fibers. The precipitation strengthening mechanisms of fine fibers (Cu,Co)6Sn5 in the β-Sn matrix increased the ultimate tensile strength (UTS) and Young’s modulus (Y) of the alloy from 30.5 MPa and 15 GPa to 44.6 MPa and 22.3 GPa, respectively, but the ductility decreased from 60 to 45.7%. The coarse fibers (Cu,Co)6Sn5 in eutectic alloys is of interest from not only increased UTS and Y to 38.7 MPa and 16.3 GPa but also maintaining the ductility at the same level, allowing for unique microstructure design. Furthermore, 0.05wt% of Co significantly reduce the onset, eutectic temperatures and undercooling, although pasty rang has been slightly raised, which may enhance the thermal characteristics. This presumably has important implications for the reliability of solders as well as their performance in electronic service.

Review of Microstructure–Mechanical Property Relationships in Cast and Wrought Ni‐Based Superalloys with Boron, Carbon, and Zirconium Microalloying Additions

Cast and wrought Ni‐based superalloys are materials of choice for harsh high‐temperature environments of aircraft engines and gas turbines. Their compositional complexity requires sophisticated thermo‐mechanical processing. A typical microstructure consists of a polycrystalline γ‐matrix, strengthening Ni3(Al,Ti) γ′ precipitates, carbides (MC, M6C, and M23C6), borides (M2B, M3B2, and M5B3), and other inclusions. Microalloying additions of B, C, and Zr commonly improve high‐temperature strength and creep resistance, although excessive additions are detrimental. Grain boundary (GB) segregation may improve cohesion and displace embrittling impurities. Finely dispersed carbides and borides are desired to control grain size via GB pinning. However, excessive decoration of GBs may lead to failure during processing and in‐service. Hence, a systematic review on the roles of B, C, and Zr in cast and wrought Ni‐based superalloys is required. The current state of knowledge on GB segregation and precipitation is reviewed. Experimental and modeling results are compared across various processing steps. The impact of GB precipitation on mechanical properties is most well researched. Co‐precipitation in proximity to GBs interacting with local microstructure evolution and mechanical properties remains less explored. Addressing these gaps in knowledge allows a more complete understanding of processing–microstructure–properties relationships in advanced cast and wrought Ni‐based superalloys.

Metallurgical Design Rules for High-Strength Steel Weld Metals

A review of a dilatometric analysis of selected Fe-C-Mn high-strength steel shielded metal arc weld metals showed that balanced Ti, B, Al, O, and N additions reduced the austenite-to-ferrite transformation-start (TS) temperature. These microalloy additions must match the following aim levels for composition control: Ti at 400 ppm (0.04 wt-%), B at 40 ppm (0.004 wt-%), Al at 200 ppm (0.020 wt-%), O at 400 ppm (0.04 wt-%), and N preferably below 80 ppm (0.008 wt-%) to ensure effective deoxidation, form complex inclusions, and distribute them to enable development of highly fracture-resistant refined weld metal microstructures. It may be wiser to avoid the rich and lean ends for these microalloy additions, except N, which should be held at the lean end, preferably much below 80 ppm (0.008 wt-%). The balanced Ti, B, Al, O, and N additions offered nearly a 100°C shift in lowering the Charpy V-notch (CVN) test temperature for either 28 or 100 J absorbed energy. Dilatometric evaluations of reheated weld metals showed that 1) the balanced Ti, B, Al, O, and N additions lowered the actual TS temperature by about 60°C compared to the calculated austenite-to-ferrite transformation temperature obtained from the constitutional equation; 2) N with more than 100 ppm (0.010 wt-%) effectively nullified the beneficial effects of Ti, B, and Al additions in lowering the transformation temperature; and 3) at N content much below 80 ppm (0.008 wt-%), both a lower TS temperature and a narrow start-to-finish (TS–Tf) temperature range helped in achieving exceptional weld metal CVN impact toughness.

Enhanced thermal stability and mechanical properties of high-temperature resistant Al−Cu alloy with Zr and Mn micro-alloying

The high temperature (HT) thermal stability and mechanical properties of Al−5%Cu (AC) and Al−5%Cu−0.2%Mn−0.2Zr% (ACMZ) alloys from 573 to 673 K were systematically studied. The results displayed that micro-alloying additions of Zr and Mn elements have presented a significant role in stabilizing the main strengthening metastable θ′ precipitates at a temperature as high as 573 K. Simultaneously, the HT tensile test demonstrated that ACMZ alloy retained their strength of (88.6±8.8) MPa, which was much higher than that of AC alloy ((32.5±0.8) MPa) after the thermal exposure at 573 K for 200 h. Finally, the underlying mechanisms of strength and ductility enhancement mechanism of the ACMZ alloy at HT were discussed in detail.

Combined experimental and DFT studies of Co82Zr12V6-xBx melt-spun ribbons to investigate structure and magnetic properties

For the development of rare-earth free permanent magnets with better performance to cost ratio, V and B dopings were employed to enhance the hard magnetic properties of Zr-Co-V-B alloys. The effect of V and B microalloying additions on the magnetic properties, phase stability and microstructure of the metastable Co5Zr phase have been investigated with experimental measurements together with first principles based on the DFT (Density Functional Theory) calculations. This study also investigates the effects of annealing at different temperatures on the intrinsic and extrinsic magnetic properties of Co82Zr12V6-xBx melt-spun ribbons. Rapidly solidified Co82Zr12V6-xBx (x = 1, 2, 3) alloy ribbons were produced by melt-spinning. For as-spun Co82Zr12V6-xBx (x = 1, 2, 3) ribbons, the coercivityHcdecreases from 2.34 kOe to 0.008 kOe with an increasing × value from 1 to 3.The amorphous alloy ribbons were annealed in a vacuum furnace at a series of temperatures of 600 °C, 650 °C, 700 °C and 750 °C each for 30 min. The XRD analysis showed the presence of two soft magnetic phases (fcc-Co and Co23Zr6), accompanied with a hard phase Co5Zr in ribbons thus leading to the desired hard/soft structure and the amount of both (hard and soft) phases increased with the annealing temperature. Coercivity was found to increase upon annealing treatment. The phase stabilities of the Co82Zr12V6-xBx ribbons were calculated from the total energy by the DFT calculations in this work. The calculated magnetic anisotropy energies have been compared to that of experimental coercivity values. Annealed sample Co82Zr12V5B1 showed the maximum coercivity value of 3.58 kOe due to the formation of a high volume fraction of hard magnetic phase (Co5Zr) and evenly distributed finer grains throughout the matrix. However, annealing under the same conditions resulted in lower coercivity of about 0.088 kOe and 1.61 kOe for Co82Zr12V3B3 and Co82Zr12V4B2 samples, respectively. Although sample Co82Zr12V4B2 exhibited higher remanence (42.80 emu/g) and maximum magnetization value with the applied field of 17 kOe (i.e. M17 = 77.70 emu/g) compared to Co82Zr12V3B3 sample.

Sensitivity of mechanical properties of pipeline steels to microalloying additions and structural characteristics

This study assesses the effect of microalloying additions and thermomechanical processing on the mechanical properties of four pipeline steels. The investigated steels had quite similar processing conditions, with some small differences, in niobium (Nb) content. The surface and center layers of the steels were characterized after thermomechanical processing, using X-ray diffraction, electron backscatter diffraction and mechanical tests. The surface layers of the steels showed shear textures, {011}<100> and {011}<211>, while conventional rolling textures were observed in the center layers. However, the steel with a very low Nb content displayed relatively stronger rotated cube {001}<110> component and a bimodal grain size distribution on the surface. Interestingly, compared to the other steels, a more significant difference in the local strain distribution, as well as the percentage of deformed and recrystallized grains, was observed between the surface and center layers of this low Nb steel. These small differences in microstructure and texture resulted in a considerable reduction in the strength and low temperature impact toughness by over 10%. Additionally, the importance of strain accumulation to the intensity of crystallographic texture was also observed. The results of this study clearly illustrate the complex interaction between thermomechanical processing and microalloying additions, which leads to differences in microstructure, texture and subsequently, the mechanical properties of steels.

Thermomechanical Processing without Accelerated Cooling to Achieve an As-Rolled Yield Strength of 400MPa in C-Mn Steel Plate

Thermomechanical (TM) rolling schedules have been developed using mathematical modelling, physical simulation and industrial trials to produce C-Mn steel plate with yield strengths of 400MPa and good impact toughness without the need of expensive micro-alloying additions or accelerated cooling. The process relies on careful selection of delay times to accumulate sufficient retained strain during austenite conditioning for enhanced nucleation of ferrite. An integrated heat transfer-austenite processing model was used to predict the final microstructure and mechanical properties. The extent of strain accumulation and progress of recrystallisation during rolling were confirmed by laboratory simulation. Based on these results, carefully controlled industrial TM rolling trials were performed on C-Mn steels. Adequate grain refinement and properties are achieved through suppression of recrystallisation and strain accumulation in the low austenite temperature region after a sufficient delay period prior to finishing.

Enhancement of Properties of Micro-alloyed Low-Carbon Ni-Added Steel by Thermomechanical Treatment

The concurrent use of micro-alloying additions and thermomechanical treatment is a common practice for obtaining high-quality grades of forged steels. Judicious use of chemistry, heat treatment schedule, and controlled processing can lead to a wide range of microstructure and thus final properties suitable for the production of different parts for the automobile industry. In this paper, thermomechanical treatment of Ni-added micro-alloyed steel containing Nb, V, Ti has been carried out with different deformation schedules (50-70%) at high temperatures followed by the varying cooling rate (i.e., forced air cooling, oil quenching, and water quenching). The cooling rates for three conditions were measured as 5 °C/s for forced air cooling, 40 °C/s for oil quenched, and 110 °C/s for water quenched samples. Thermomechanical and post-tempering treatment cycles were employed for the steel with 1150 and 900 °C as upper and lower forging temperatures. The best combination of properties viz; YS: 1044 MPa, UTS: 1308 MPa, % El: 16.7, %RA: 57 and Impact Toughness: 50 J/cm2 could be achieved for 70% deformed samples, followed by forced air cooling. The reasons have been attributed to the segregation of Ti & Nb carbides at grain boundaries as revealed by microstructural analysis. This has led to restriction of grain boundary coarsening at high temperatures. Further, fine vanadium carbide and the presence of retained austenite have contributed to improving the elongation and toughness values.

Effect of Niobium Micro-Alloying Addition on Electrochemical Corrosion Behavior of Mild Steel in a Highly Alkaline Environment

Effect of Niobium Micro-Alloying Addition on Electrochemical Corrosion Behavior of Mild Steel in a Highly Alkaline Environment

Effect of niobium on the microstructure and properties of submerged arc welds in HSLA steel

High-strength low-alloy or microalloyed steels are thermo-mechanically control processed (TMCP) to achieve desired microstructures and mechanical properties, and microalloy additions are critical for obtaining optimum properties. The steel of interest in this study is microalloyed with approximately 0.1 wt% Nb, levels that are typical in pipeline steels such as X70. Submerged arc welding (SAW) is a commonly utilized manufacturing method for constructing pipe segments via seam welding. There were two parts to this investigation. Part 1 analyzed controlled dilution levels consisting of commercially available SAW electrodes and Nb-bearing steel in proportions to simulate submerged arc weld metal. Part 2 of this investigation evaluated actual submerged arc welds on low-alloy steels. Bead-on-plate welds were deposited, and the Nb content of the weld metal was systematically increased by adding ferro-niobium directly to the flux. Two-run welds representative of line pipe production were also evaluated using the same ferro-niobium flux additions in order to increase the weld metal Nb content. The microstructural evolution and corresponding mechanical properties with increased Nb are evaluated based on this work and on the published literature.

Effect of Sc microalloying addition on microstructure and mechanical properties of as-cast Al–12Si alloy

The effect of microalloying 0.1 wt% Sc on microstructure and mechanical properties of as-cast Al–12Si (wt.%) alloys was investigated. Sc refines α-Al grain average size from 400 μm to 135 μm and eutectic Si average size from 4.6 μm to 0.7 μm, and modifies Si from plate-like shape to fibers as well. The microaddition of Sc also leads to the formation of coherent nanosized Al3Sc precipitation and other Sc containing intermetallic phases with a length <10 μm. The tensile strength increases from 183 MPa of the base alloy to 254 MPa of the Sc-modified alloy, and the elongation increases from 3.5% to 8.3%, respectively. Moreover, this Sc-modified alloy has a retention of 85% strength even after thermal exposure at 350 °C for 160 h.

Effect of Nb-C addition on the microstructure and mechanical properties of CoCrFeMnNi high entropy alloys during homogenisation

In the present paper, CoCrFeMnNi(NbC) alloy was designed based on theoretical calculations and proposed as a novel high entropy alloy. The effect of Nb-C microalloy addition on the microstructure and mechanical properties of equiatomic CoCrFeMnNi high entropy alloys were studied during homogenisation. The chemical composition, microstructural evolution, hardness and shear deformation behaviour were analysed using XRF, Leco-combustion technique, optical microscopy, SEM-WDX, XRD, Vickers hardness and shear punch testing. Moreover, the thermal behaviour of both alloys during heating stage was studied by differential thermal analysis technique at a heating rate of 10 °C/min. The experimental results confirmed theoretical calculations based on Scheil-Gulliver solidification model and thermodynamic rules, suggesting a solid solution high entropy alloy with FCC-crystal structure after vacuum arc re-melting and homogenisation. SEM-WDX analysis hardly showed any Nb-containing precipitates in both as-cast and homogenised samples. It was also found that Nb-C addition considerably retarded the growth/coarsening of grain size during homogenisation. Moreover, the results suggested that the hardness and shear strength of CoCrFeMnNiNbC alloy was higher than CoCrFeMnNi alloy, mainly due to solid solution strengthening effect.

Microstructural evolution and precipitation behavior of the warm-rolled medium Mn steels containing Nb or Nb-Mo during intercritical annealing

The microstructural evolution and precipitation behavior of the warm-rolled (WRed) medium Mn steels with no microalloying addition, single Nb addition and multiple Nb-Mo addition treated at 650 °C for various durations were investigated. Different from the lamellar microstructure of hot rolled medium Mn steels and the equiaxed microstructure of cold rolled medium Mn steels after intercritical annealing, the WRed samples of medium Mn steels exhibited the equiaxed and lamellar mixed microstructure, and the equiaxed microstructure ratio became larger with increasing durations. The addition of Nb or Nb-Mo can respectively increase yield strength of ~ 50 MPa or ~ 180 MPa in average and ultimate tensile strength of ~ 70 MPa or ~ 100 MPa in average without sacrificing the tensile ductility. The stability of austenite can be improved for the smaller average austenite grain size due to the addition of Nb or Nb-Mo. The addition of Mo to the Nb-bearing medium Mn steel can increase the density of nano-precipitates by reducing the mismatch degree between the matrix and precipitates and inhibit the coarsening rate of precipitates.

Electrodeposition of Mg-Based Alloys for Anti-Corrosion and Energy Storage Applications

Magnesium has gained a lot of attention due to its inherent properties such as light-weight with a density of 1.7 g/cm3 and the highest strength to weight ratio. Such unique properties make magnesium a suitable candidate for various applications including vehicles, aerospace projects, construction, energy storage applications and medical implants. One of the crucial issues with the use of magnesium on these applications is the tendency of the material to corrode. This is due to the high chemical activity of magnesium, its standard equilibrium potential of Mg/Mg2+ is -2.4 V vs. NHE. To prevent these problems, there have been reported strategies such as formation of alloys with noble metals or inert elements and the protection of the metal with a coating film.1 From the mentioned solutions, the most suitable solutions to prevent corrosion on magnesium without compromising its properties are the formation of alloys using passive elements such as Al, Ni or Cr and the protection of magnesium with a coating film. 2,3 Based on these two solutions, we propose to use aluminum as the second element for the alloy formation to prevent corrosion of magnesium and to enhance its structural, thermal, and electrical performance. In our study, we’ve been able to produce magnesium alloys by electro-co-deposition which have demonstrated to have a lower corrosion behavior compared to pristine magnesium films. Similarly, magnesium-based materials are gaining interest in energy storage application due to two-electron transfer per a reaction and thus a high volumetric capacity compared to the state-of-art Li-ion batteries. Also, they have shown to be safer than Li since Mg during cycling do not form dendrites.4 Herein, we explore the use of electro-co-deposited Mg-Al alloy as electrodes to construct high energy rechargeable Mg batteries. References (1) Esmaily, M.; Svensson, J. E.; Fajardo, S.; Birbilis, N.; Frankel, G. S.; Virtanen, S.; Arrabal, R.; Thomas, S.; Johansson, L. G. Fundamentals and Advances in Magnesium Alloy Corrosion. Prog. Mater. Sci. 2017, 89, 92–193. (2) Liu, R. L.; Scully, J. R.; Williams, G.; Birbilis, N. Reducing the Corrosion Rate of Magnesium via Microalloying Additions of Group 14 and 15 Elements. Electrochim. Acta 2018, 260, 184–195. (3) Yuwono, J. A.; Birbilis, N.; Liu, R.; Ou, Q.; Bao, Q.; Medhekar, N. V. Aqueous Electrochemical Activity of the Mg Surface: The Role of Group 14 and 15 Microalloying Elements. J. Electrochem. Soc. 2017, 164 (13), C918–C929. (4) Bucur, C. B. Challenges of a Rechargeable Magnesium Battery A Guide to the Viability of This Post Lithium-Ion Battery, 1st editio.; Spinger Briefs in Energy, 2018.