Effect of Ni Coating on Hydrogenation Kinetics in Pure Mg and Mg-Mg2Ni Eutectic Alloy

We have applied hybridization method to the surface modification by Ni coating on powder specimens of pure Mg and Mg-Mg2Ni eutectic alloy, and investigated the effect of the Ni coating on the hydrogenation kinetics in them. The hydrogenation kinetics at 350 degree C is greatly increased by the Ni coating for both the pure Mg and Mg-Mg2Ni eutectic alloy specimens. Thus, it is confirmed that the surface modification by the hybridization method is considerably effective to improve the hydrogenation kinetics in them. This improvement is thought to be a catalytic effect of the coated Ni. The hydrogenation kinetics of the Mg-Mg2Ni alloy specimen heat-treated at 470 degree C has increased compared with that of the as-cast alloy specimen. It is also confirmed that hydrogenation kinetics improves by the heat treatment to grow the eutectic structure consisted of Mg2Ni phase and Mg phase.

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Hydrogenation Kinetics of Ni Coated Mg and Mg-Mg2Ni Eutectic Alloy by Hybridization Method

Journal of the Japan Institute of Metals and Materials ◽

10.2320/jinstmet.71.164 ◽

2007 ◽

Vol 71 (2) ◽

pp. 164-169 ◽

Cited By ~ 9

Author(s):

Masaaki Kusumoto ◽

Hideyuki Saitoh

Keyword(s):

Eutectic Alloy ◽

Hybridization Method ◽

Hydrogenation Kinetics ◽

Kinetics Of

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Microstructure Characterization and Mechanical Properties of a Zn and Rare Earth Modified Mg Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.727-728.111 ◽

2015 ◽

Vol 727-728 ◽

pp. 111-114 ◽

Cited By ~ 1

Author(s):

Li Yuan Sheng ◽

Fang Yang ◽

Ting Fei Xi

Keyword(s):

Mechanical Properties ◽

Cast Alloy ◽

Hot Extrusion ◽

Eutectic Structure ◽

Crystal Defects ◽

Treatment Results ◽

Nanoscale Particles ◽

Residual Phase ◽

Heat Treated ◽

The Matrix

In the present paper, the Mg-Zn-Y-Nd alloy is fabricated by as casting and hot extrusion. Microstructure and mechanical properties of the as-cast, heat treated and hot extruded alloys are investigated. The results exhibit that Mg24Y5 phase with eutectic structure forms in the as-cast alloy, which has an orientation relationship with matrix of . The precipitating phase separates the matrix semi-continuously. The heat treatment results in most precipitates solid soluted into matrix, but there are still some nanoscale particles and residual phase along grain boundary. The hot extrusion refines the microstructure and leads to the formation of stacking faults in the matrix. Compared with the as-cast and heat treated alloy, the hot extruded alloy obtain great improvement in mechanical properties, which should be attributed to the grain refinement, solid solution and fomation of crystal defects

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Microstructure Evolution of Conventional and Semi-Solid A356 Alloy with Addition of Strontium

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1087.488 ◽

2015 ◽

Vol 1087 ◽

pp. 488-492

Author(s):

Yuan Sieng Seo ◽

Laila Masrur Mohd Nasir ◽

Hussain Zuhailawati ◽

Anasyida Abu Seman

Keyword(s):

Phase Analysis ◽

Eutectic Alloy ◽

Cast Alloy ◽

Dendritic Structure ◽

A356 Alloy ◽

Melting Furnace ◽

Eutectic Structure ◽

Globular Structure ◽

Semi Solid ◽

Steel Mould

In this study, modification of aluminium silicon eutectic alloy by grain modifier, strontium was investigated on conventional and slope cast A356 alloy. A356 alloy with addition of 0 to 0.97 wt.% Sr was prepared by conventional and slope casting in melting furnace. The molten metal of A356 alloy was casted into steel mould. Microstructure was observed using SEM. Phase analysis was done using XRD. Microhardness was conducted using Vicker microhardness. Microstructure of conventional cast displayed dendritic structure whereas slope cast displayed globular structure. Addition of Sr refined eutectic structure in both conventional and slope cast alloy. Phase analysis revealed the presence of Al2Sr phase in conventional cast Al-6Si-0.97Sr. Microhardness of the conventional cast alloy decreased with increasing of Sr up to 0.97 wt.%.

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Microstructure and Mechanical Properties of Ultrafine Quaternary Al-Cu-Si-Mg Eutectic Alloy

Metals ◽

10.3390/met12010007 ◽

2021 ◽

Vol 12 (1) ◽

pp. 7

Author(s):

Qing Cai ◽

Brian Cantor ◽

Vivian S. Tong ◽

Feng Wang ◽

Chamini L. Mendis ◽

...

Keyword(s):

Mechanical Properties ◽

Eutectic Alloy ◽

Cast Alloy ◽

Eutectic Reaction ◽

High Strength ◽

Eutectic Structure ◽

Eutectic Cell ◽

Orientation Relationships ◽

Arc Melting ◽

Alloy Microstructure

The microstructure evolution and mechanical properties of quaternary Al-Cu-Si-Mg eutectic alloy prepared via arc melting and suction casting were studied. This alloy exhibits a single endothermic DSC peak with a melting temperature of 509 °C upon heating, suggesting a eutectic reaction. The cast alloy microstructure consisted of four phases, α-Al, Al2Cu (), Si and Al4Cu2Mg8Si7 (Q), in the eutectic cells and also in the nano-scale anomalous eutectic in the intercellular regions. The eutectic cells show different morphologies in different parts of the sample. Well-defined orientation relationships between the α-Al, Al2Cu, and Q phases were found in the eutectic cell centres, while decoupled growth of Q phase occurred at the cell boundaries. The bimodal microstructure exhibits excellent compressive mechanical properties, including a yield strength of 835 ± 35 MPa, a fracture strength of ~1 GPa and a compressive fracture strain of 4.7 ± 1.1%. The high strength is attributed to a combination of a refined eutectic structure and strengthening from multiple hard phases.

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Single-walled carbon nanotubes/lithium borohydride composites for hydrogen storage: role of in situ formed LiB(OH)4, Li2CO3 and LiBO2 by oxidation and nitrogen annealing

RSC Advances ◽

10.1039/c9ra06916j ◽

2019 ◽

Vol 9 (54) ◽

pp. 31483-31496 ◽

Cited By ~ 2

Author(s):

Lathapriya Vellingiri ◽

Karthigeyan Annamalai ◽

Ramamurthi Kandasamy ◽

Iyakutti Kombiah

Keyword(s):

Catalytic Effect ◽

Single Walled Carbon Nanotubes ◽

Ambient Conditions ◽

Lithium Borohydride ◽

Hydrogenation Kinetics ◽

Nitrogen Annealing ◽

Walled Carbon Nanotubes ◽

Kinetics Of

In situ formed Li+[B(OH)4]−, Li2+[CO3]− & Li+[BO2]− on the surface of SWCNT@LiBH4 not only stabilizes the composites in ambient conditions but also enhanced the de- and re-hydrogenation kinetics of the composites through catalytic effect.

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Stable and Metastable Phase Equilibria Involving the Cu6Sn5 Intermetallic

Journal of Electronic Materials ◽

10.1007/s11664-021-09067-4 ◽

2021 ◽

Author(s):

A. Leineweber ◽

M. Löffler ◽

S. Martin

Keyword(s):

Phase Equilibria ◽

Electron Backscatter Diffraction ◽

Metastable Phase ◽

Stable Phase ◽

X Ray Diffraction ◽

X Ray ◽

Heat Treated ◽

Ordered Phases ◽

Backscatter Diffraction ◽

Kinetics Of

Abstract Cu6Sn5 intermetallic occurs in the form of differently ordered phases η, η′ and η′′. In solder joints, this intermetallic can undergo changes in composition and the state of order without or while interacting with excess Cu and excess Sn in the system, potentially giving rise to detrimental changes in the mechanical properties of the solder. In order to study such processes in fundamental detail and to get more detailed information about the metastable and stable phase equilibria, model alloys consisting of Cu3Sn + Cu6Sn5 as well as Cu6Sn5 + Sn-rich melt were heat treated. Powder x-ray diffraction and scanning electron microscopy supplemented by electron backscatter diffraction were used to investigate the structural and microstructural changes. It was shown that Sn-poor η can increase its Sn content by Cu3Sn precipitation at grain boundaries or by uptake of Sn from the Sn-rich melt. From the kinetics of the former process at 513 K and the grain size of the η phase, we obtained an interdiffusion coefficient in η of (3 ± 1) × 10−16 m2 s−1. Comparison of this value with literature data implies that this value reflects pure volume (inter)diffusion, while Cu6Sn5 growth at low temperature is typically strongly influenced by grain-boundary diffusion. These investigations also confirm that η′′ forming below a composition-dependent transus temperature gradually enriches in Sn content, confirming that Sn-poor η′′ is metastable against decomposition into Cu3Sn and more Sn-rich η or (at lower temperatures) η′. Graphic Abstract

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