Thermodynamics and kinetics of phase transformation in rare earth–magnesium alloys: A critical review

Luo, Qun; Guo, Yan‐Lin; Liu, Bin; Feng, Yujun; Zhang, Jieyu; Li, Qian; Chou, Kuo‐Chih

doi:10.1016/j.jmst.2020.01.022

Cited by 597 publications

(61 citation statements)

References 286 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A variety of materials, such as AB x ‐type, rare earth‐based, Ti‐based and Mg‐based alloys, nanocomposites etc. have been evaluated and proved to be effective anode materials for Ni‐MH batteries 3‐9 . Moreover, due to the high redox reaction activity, varied morphology and multiple valence states of cobalt atom, cobalt compounds have been studied as the promising electrodes for high‐performance energy storage device over the past years.…”

Section: Introductionmentioning

confidence: 99%

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite

Liu

Chen

et al. 2020

Int J Energy Res

View full text Add to dashboard Cite

A facile one-pot reduction process is used to obtain the cobalt/graphene composite (CoRGO). The CoRGO materials exhibit unique reticular globular morphology. Co 9 S 8 hydrogen storage alloy is fabricated via mechanical alloying method. Different amounts of CoRGO are coated on the surface of Co 9 S 8 alloy by ball milling. The electrochemical characterizations of the composites are conducted in the standard tri-electrode system. Ultimately, the CoRGO coated Co 9 S 8 electrode shows preferable performance than the RGO modified alloy (603.6 mAh/g) and original alloy (577.3 mAh/g). As the additive content of CoRGO is 6 wt%, a maximum discharge capacity of 637.5 mAh/g is obtained. Furthermore, the cycle stability and high-rate dischargeability of the electrode are also enhanced. The Co particles in the CoRGO participate in the reversible redox reactions and the graphene provides high conductivity. The CoRGO with distinctive structure and morphology can not only improve the electrocatalytic activity but also increase the specific surface area of Co 9 S 8 alloy. The cobalt and graphene species in the CoRGO composite serve a synergistic effect in further facilitating the hydrogen diffusion, expediting the charge transfer in/on the alloy and improving the corrosion resistance, thus enhancing the electrochemical performance and reaction kinetics of Co 9 S 8 alloy.

show abstract

Section: Introductionmentioning

confidence: 99%

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite

Liu

Chen

et al. 2020

Int J Energy Res

View full text Add to dashboard Cite

show abstract

“…There are a large number of fruitful results in superlattice structure of A 2 B 7 -type hydrogen storage alloys because of high specific energy density at room temperature [9][10][11][12][13][14][15][16][17][18]. For instance, Yuan et al [19] proposed that the effect of discharge capacity of La-Mg-Ni-based alloys with Mo substitution at low-temperatures and the optimized composition could discharge 334.6 mAh g -1 at 253 K. Moreover, low-temperature cycling performance of La-Mg-Ni-based superlattice alloys also was investigated by Lv and Wu [20] through different line velocity by melt-spinning method, indicating that the discharge capacity could reach 245.9 mAh g -1 at 248 K after 100th cycle by 10 m s -1 spinning rate.…”

Section: Introductionmentioning

confidence: 99%

Superior electrochemical characteristics of A2B7-type hydrogen storage alloy at ultralow temperature with the addition of alane

Liang

Yan

et al. 2021

J Mater Sci

View full text Add to dashboard Cite

In an attempt to enhance the low-temperature dischargeability of A 2 B 7 -type hydrogen storage alloy, the addition of alane (AlH 3 ) by convenient ball milling method was investigated based on La-Y-Ni superlattice alloy containing Y 2 Ni 7type phase and YNi 3 -type phase primarily. The maximum discharge capacity of the composite with doping 1 wt.% AlH 3 increased by 364.2% reaching 208.9 mAh g -1 at 233 K compared with the pristine sample. The initial high-rate discharge capacity of doping 1 wt.% AlH 3 sample reached 151.7 mAh g -1 at 4000 mA g -1 current density. The improvement could be ascribed to strengthening of hydrogen diffusion channel and acceleration of H-kinetics at low temperatures derived from formation of new porous structure and modification of lattice defects by dissolution of aluminum on the surface. It has made a powerfully contribution to a pace of commercialization of A 2 B 7 -type superlattice hydrogen storage alloy applying in high altitude or latitude regions.

show abstract

“…What is more, the thermodynamic information is very important for the effective alloy design as well as the prediction of the distribution of impurities in alloys. [ 27–29 ] However, there is little thermodynamic information on the dilute part of the phase diagram. The currently measured content of Fe, Ni, Cr in liquids is also valuable experimental data for the revision of current thermodynamic database.…”

Section: Introductionmentioning

confidence: 99%

Effect of Steels on the Purity of Molten Mg Alloys

et al. 2020

View full text Add to dashboard Cite

Magnesium (Mg) alloys have received extensive attention in industrial applications due to their low density, low modulus of elasticity, high-specific strength, and high-specific stiffness. [1-4] However, the low-temperature formability [5] and low corrosion resistance [6-8] of Mg alloys limit their large-scale applications. Many researches have indicated that the impurity elements, Fe, Ni, Cu, Co, in Mg alloys can strongly increase their corrosion rate, [9-11] and also severely deteriorate the mechanical [12-14] and damping properties. [15] When the impurities content in alloys exceeds the "tolerance limit" (10 ppm magnitude), the corrosion rate of Mg alloys will be exponentially accelerated. [16] Therefore, it is of great significance to strictly control the purity of the Mg alloys, especially the purity of the molten alloys before casting. Unfortunately, it is almost impossible to completely avoid these impurities during the production of Mg alloys. First, during Mg-metal smelting, no matter whether the Pidgeon method or the electrolytic magnesium method is used, there are always some impurities picked up from the raw materials. Second, these elements existing in the steel tools and steel crucibles can be dissolved in the molten Mg alloys during the melting process. [17-20] The purification of the molten Mg and Mg alloys has been studied extensively. [21-24] However, the effect resulting from defined tools on the Mg alloys production is rarely studied. [19,25] Scharf and Ditze [19] studied the interaction layers between AZ91 and AS31 with steel crucibles. The dissolution of iron, lowcarbon steel, and SUS316 (11wt% Ni, 17wt% Cr, remainder Fe) crucibles in commercial pure molten Mg was investigated by Taninouchi et al. [25] However, the influence of the types of used steels on the purity of molten Mg alloys has not been studied. Only by understanding the specific impact of elements coming from the tooling materials on the purity of molten Mg alloys can assure the purity of Mg alloys. This work aims to quantitatively determine the effect of tooling materials on the purity of Mg alloys melt. The most commonly cast Mg alloys, AZ91D, and AM50A, were studied. Three types of common tooling materials used in the production of Mg alloys: 20# steel, H13 steel, High-CrNi (022Cr25Ni7Mo4N) steel, were studied. Low carbon steel (here 20#) is the most common material used as the crucible materials for the Mg alloys synthesis. H13 steel is commonly used for Mg alloys casting molds. High-CrNi heat-resistant steel is commonly seen for the reduction tank in the Pidgeon process. The interactions between these tooling materials and Mg alloys were pre-evaluated using the Thermo-Calc 2019 software [26] based on the TCMG5 thermodynamic database. The influence of tooling materials on the purity of molten Mg alloys was experimentally studied using the liquid-solid diffusion method. What is more, the thermodynamic information is very important for the effective alloy design as well as the prediction of the distribution of impurities in al...

show abstract

Thermodynamics and kinetics of phase transformation in rare earth–magnesium alloys: A critical review

Cited by 597 publications

References 286 publications

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite

Superior electrochemical characteristics of A2B7-type hydrogen storage alloy at ultralow temperature with the addition of alane

Effect of Steels on the Purity of Molten Mg Alloys

Contact Info

Product

Resources

About

Thermodynamics and kinetics of phase transformation in rare earth–magnesium alloys: A critical review

Cited by 597 publications

References 286 publications

Preparation and electrochemical hydrogen storage properties of Co 9 S 8 alloy coated with cobalt/graphene composite

Preparation and electrochemical hydrogen storage properties of Co 9 S 8 alloy coated with cobalt/graphene composite

Superior electrochemical characteristics of A2B7-type hydrogen storage alloy at ultralow temperature with the addition of alane

Effect of Steels on the Purity of Molten Mg Alloys

Contact Info

Product

Resources

About

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite

Preparation and electrochemical hydrogen storage properties of Co ₉ S ₈ alloy coated with cobalt/graphene composite