Achieving Ultrahigh Anodic Efficiency via Single-Phase Design of Mg–Zn Alloy Anode for Mg–Air Batteries

2021 ◽  
Author(s):  
Bo Xiao ◽  
Fuyong Cao ◽  
Tao Ying ◽  
Ziming Wang ◽  
Dajiang Zheng ◽  
...  
Keyword(s):  
Single Phase ◽  
Alloy Anode ◽  
Anodic Efficiency ◽  
Phase Design ◽  
Zn Alloy

HRTEM Observation of α-Phase in Cu-Zn Alloy Annealed at Lower Temperature

2007 ◽  
Vol 26-28 ◽  
pp. 1279-1282 ◽  
Author(s):  
Koji Kato ◽  
Daisuke Hamatani ◽  
Kenji Matsuda ◽  
Tokimasa Kawabata ◽  
Yasuhiro Uetani ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Phase Decomposition ◽  
Β Phase ◽  
Α Phase ◽  
Transmission Electron ◽  
Hrtem Observation ◽  
Lower Temperature ◽  
Zn Alloy

It is known that the phase-decomposition process of 60/40 Cu-Zn alloy is so-called the bainitic transformation, and decomposition of α-phase from the β’-phase is as follow: β’ → α9R → αfcc. In this work,decomposition of α-phase from the β’ single phase of Cu-40.26at.%Zn alloy has been investigated by high-resolution transmission electron microscopy (HRTEM) to understand the phase transformation of this alloy. Especially, striations in the α-phase has been focused on the special feature for the change of the structure and hardening of this alloy during annealing. The result of a comparison between this alloy and the Si added alloy is also reported.

Isothermal Section of the Sn-Fe-Zn Ternary System at 270°C

2013 ◽  
Vol 284-287 ◽  
pp. 152-157
Author(s):  
Yee Wen Yen ◽  
Yu Pin Hsieh ◽  
Wan Ching Chen ◽  
Chien Chung Jao
Keyword(s):  
Isothermal Section ◽  
Ternary System ◽  
Ternary Phase ◽  
Single Phase ◽  
Ternary Phase Diagram ◽  
Electronic Industry ◽  
Two Phase ◽  
Rich Alloy ◽  
Ternary Intermetallic Compound ◽  
Zn Alloy

With a relatively low liquidus temperature, the eutectic Sn-Zn alloy is suitable replacement for conventional eutectic Sn-Pb solder in the electronic industry. One of the most important materials as a lead-frame is Fe-42Ni alloy (Alloy 42) in the microelectronic packaging. The Sn-Fe-Zn ternary phase diagram is a powerful and useful tool to understand the interfacial reactions between Sn-Zn alloy and Alloy 42 substrate (Fe-rich alloy). The isothermal section of the Sn-Fe-Zn ternary system was experimentally investigated at 270oC in this study. Ternary Sn-Fe-Zn alloys were prepared and annealed at 270 oC to determine the isothermal section of the Sn-Fe-Zn ternary system. The experimental results revealed that no ternary intermetallic compound was formed, and noticeable Zn solubility was observed in the FeSn2 phase. The isothermal section of the Sn-Fe-Zn ternary system consists of nine single-phase areas, thirteen two-phase areas, and seven tie-triangles at 270 oC

Two-phase approaches to point and transect relascope sampling of downed logs

2001 ◽  
Vol 31 (6) ◽  
pp. 971-977 ◽  
Author(s):  
Anna Ringvall ◽  
Göran Ståhl ◽  
Vera Teichmann ◽  
Jeffrey H Gove ◽  
Mark J Ducey
Keyword(s):  
Coarse Woody Debris ◽  
Single Phase ◽  
Woody Debris ◽  
Standard Errors ◽  
Auxiliary Variables ◽  
Inventory Cost ◽  
Two Phase ◽  
Auxiliary Data ◽  
Total Length ◽  
Phase Design

Point relascope sampling and transect relascope sampling were recently proposed as methods for the inventory of downed coarse woody debris. By only counting logs with a relascope device, the total length squared (with point relascope sampling) or the total length (with transect relascope sampling) of downed logs in an area can be estimated. For estimates of other variables, such as volume, additional measurements on the sampled logs are required. In this article, two-phase approaches to the methods are presented that makes use of the estimates from fast counts of logs as auxiliary data. The presented approaches serve two purposes: (i) to improve the efficiency of the methods and (ii) to avoid the bias that is likely to occur if careful checks of whether or not doubtful logs should be counted are neglected. Each two-phase design was compared with a single-phase design in terms of the standard error obtained for a given inventory cost. The two-phase designs decreased the standard errors with ca. 17–18% for points and 10–15% for lines. Including subjective judgements as additional auxiliary variables further decreased the standard errors in the line case but not in the point case. In the former case, the improvement in comparison with the single-phase design was 17–23%.

scholarly journals Preferential Orientation of .ALPHA. Phase With the Matrix of .BETA.' Single Phase in Cu-41.7%Zn Alloy.

1992 ◽  
Vol 41 (460) ◽  
pp. 11-16 ◽  
Author(s):  
Susumu IKENO ◽  
Masaru AOKI ◽  
Kenji MATSUDA ◽  
Yasuhiro UETANI ◽  
Shizuo TADA
Keyword(s):  
Single Phase ◽  
Alpha Phase ◽  
Preferential Orientation ◽  
The Matrix ◽  
Zn Alloy

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

A study of interface sliding at F.C.C.-B.C.C. boundaries in a Cu-Zn alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 422-423
Author(s):  
F. Monchoux ◽  
A. Rocher ◽  
J.L. Martin
Keyword(s):  
Face Centered Cubic ◽  
Creep Tests ◽  
High Voltage Electron Microscopy ◽  
Diffusion Treatment ◽  
Voltage Electron ◽  
The Face ◽  
Face Centered ◽  
Interface Sliding ◽  
Zn Alloy ◽  
Made In

Interphase sliding is an important phenomenon of high temperature plasticity. In order to study the microstructural changes associated with it, as well as its influence on the strain rate dependence on stress and temperature, plane boundaries were obtained by welding together two polycrystals of Cu-Zn alloys having the face centered cubic and body centered cubic structures respectively following the procedure described in (1). These specimens were then deformed in shear along the interface on a creep machine (2) at the same temperature as that of the diffusion treatment so as to avoid any precipitation. The present paper reports observations by conventional and high voltage electron microscopy of the microstructure of both phases, in the vicinity of the phase boundary, after different creep tests corresponding to various deformation conditions.Foils were cut by spark machining out of the bulk samples, 0.2 mm thick. They were then electropolished down to 0.1 mm, after which a hole with thin edges was made in an area including the boundary

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

Observation of pseudo 10-fold symmetry in the ordered iron-zinc delta phase

1992 ◽  
Vol 50 (1) ◽  
pp. 36-37
Author(s):  
L. A. Giannuzzi ◽  
A. S. Ramani ◽  
P. R. Howell ◽  
H. W. Pickering ◽  
W. R. Bitler
Keyword(s):  
Single Phase ◽  
X Ray Diffraction ◽  
Rich Region ◽  
Average Cell ◽  
X Ray ◽  
Delta Phase ◽  
Cell Dimensions ◽  
Δ Phase ◽  
Morphological Differences ◽  
Concentration Discontinuity

The δ phase is a Zn-rich intermetallic, having a composition range of ∼ 86.5 - 92.0 atomic percent Zn, and is stable up to 665°C. The stoichiometry of the δ phase has been reported as FeZn7 and FeZn10 The deviation in stoichiometry can be attributed to variations in alloy composition used by each investigator. The structure of the δ phase, as determined by powder x-ray diffraction, is hexagonal (P63mc or P63/mmc) with cell dimensions a = 1.28 nm, c = 5.76 nm, and 555±8 atoms per unit cell. Later work suggested that the layer produced by hot-dip galvanizing should be considered as two distinct phases which are characterized by their morphological differences, namely: the iron-rich region with a compact appearance (δk) and the zinc-rich region with a columnar or palisade microstructure (δp). The sub-division of the δ phase was also based on differences in diffusion behavior, and a concentration discontinuity across the δp/δk boundary. However, work utilizing Weisenberg photographs on δ single crystals reported that the variation in lattice parameters with composition was small and hence, structurally, the δk phase and the δp phase were the same and should be thought of as a single phase, δ. Bastin et al. determined the average cell dimensions to be a = 1.28 nm and c = 5.71 nm, and suggested that perhaps some kind of ordering process, which would not be observed by x-ray diffraction, may be responsible for the morphological differences within the δ phase.

A TEM study of the influence of microstructure on the superplastic behavior of a U-5.8 wt.% Nb alloy

1986 ◽  
Vol 44 ◽  
pp. 568-569
Author(s):  
G. Mackiewicz Ludtka
Keyword(s):  
Grain Size ◽  
Heating Rate ◽  
Phase Field ◽  
Single Phase ◽  
Superplastic Behavior ◽  
Two Phase ◽  
Single Phase Field

Historically, metals exhibit superplasticity only while forming in a two-phase field because a two-phase microstructure helps ensure a fine, stable grain size. In the U-5.8 Nb alloy, superplastici ty exists for up to 2 h in the single phase field (γ1) at 670°C. This is above the equilibrium monotectoid temperature of 647°C. Utilizing dilatometry, the superplastic (SP) U-5.8 Nb alloy requires superheating to 658°C to initiate the α+γ2 → γ1 transformation at a heating rate of 1.5°C/s. Hence, the U-5.8 Nb alloy exhibits an anomolous superplastic behavior.

TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

1994 ◽  
Vol 52 ◽  
pp. 628-629
Author(s):  
J. Fang ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Residual Stress ◽  
Single Phase ◽  
Stress Relief ◽  
Stress Recovery ◽  
Surface Residual Stress ◽  
Microscopic Mechanism ◽  
Sic Particles ◽  
Annealing Procedure ◽  
The Difference ◽  
Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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