The Copper-Arsenic Eutectic and the Cu3As Phase

2020 ◽  
Vol 405 ◽  
pp. 19-25
Author(s):  
Roland Haubner ◽  
Susanne Strobl
Keyword(s):  
Solid Solution ◽  
Eutectic Point ◽  
Rich Phase ◽  
Inverse Segregation ◽  
Lamella Thickness ◽  
Pure Cu ◽  
Copper Arsenic

In ancient bronze ingots Cu3As was observed beside other impurities like Sb. Moreover, the Cu-As bronzes were studied concerning the decrease in As during melting respectively remelting. To verify the microstructure and hardness of the eutectic and Cu3As phase appropriate mixtures were produced by melting pure Cu and As. The eutectic point in the Cu-As system is at 685 °C and 20.8 wt. % As and the Cu3As phase with 29.56 wt. % As melts at 827 °C. In the sample´s core the microstructure is a homogeneous eutectic, but near the surface it becomes hypoeutectic, i.e. an As loss took place. The lamella thickness of the eutectic was in the range of about 1 µm. The sample with a Cu3As composition showed a proeutectic microstructure with mainly Cu3As and a small amount of eutectic. In the large Cu3As crystals twin lamellae were observed. Additionally, by Vickers indents new twins were introduced. The microhardness of the Cu-As solid solution is 78 HV0.025, of the eutectic 125 HV0.025 and of the Cu3As phase 158 HV0.025. On some surfaces of the Cu3As sample a Cu-rich phase was observed. We are not able to explain this phenomenon, but it is definitively no “inverse segregation”.

scholarly journals Effect of the Fe2O3 Addition Amount on Dephosphorization of Hot Metal with Low Basicity Slag by High-Temperature Laboratorial Experiments

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 417
Author(s):  
Wenkui Yang ◽  
Jian Yang ◽  
Yanqiu Shi ◽  
Zhijun Yang ◽  
Fubin Gao ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Theoretical Calculation ◽  
Oxygen Potential ◽  
Oxygen Activity ◽  
Hot Metal ◽  
Rich Phase ◽  
Addition Amount

In this paper, the influence of the Fe2O3 addition amount on the dephosphorization of hot metal at 1623 K with the slag of the low basicity (CaO/SiO2) of about 1.5 was investigated by using high-temperature laboratorial experiments. With increasing the Fe2O3 addition amount from 5 to 30 g, the contents of [C], [Si], [Mn] and [P] in the hot metal at the end of dephosphorization are decreased and the corresponding removal ratios increase. In dephosphorization slags, the phosphorus mainly exists in the form of the nCa2SiO4–Ca3(PO4)2 solid solution in the phosphorus-rich phase and the value of coefficient n decreases from 20 to 1. Furthermore, the oxygen potential and activity at the interface between the slag and hot metal are increased. When the oxygen potential and the oxygen activity at the interface are greater than 0.72 × 10−12 and 7.1 × 10−3, respectively, the dephosphorization ratio begins to increase rapidly. When the Fe2O3 addition amount is increased to 30 g, the ratio of the Fe2O3 addition amount to theoretical calculation consumption is around 175%, and the dephosphorization ratio reaches the highest value of 83.3%.

Synthesis of Nanocrystalline Ag-Cu Supersaturated Solid Solution by Mechanical Alloying

2010 ◽  
Vol 92 ◽  
pp. 271-276 ◽  
Author(s):  
Liang Feng Li ◽  
Tai Qiu ◽  
Jian Yang ◽  
Yong Bao Feng
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Mechanical Alloying ◽  
Solid Solutions ◽  
Supersaturated Solid Solution ◽  
Main Peak ◽  
Rich Phase ◽  
Transmission Electron ◽  
Supersaturated Solid Solutions ◽  
Xrd Patterns

Nanocrystalline Ag-28Cu supersaturated solid solution is prepared by mechanical alloying (MA) using a planetary ball mill. The mechanical alloyed powders are characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and differential scanning calorimeter (DSC). XRD patterns show that the main peak of Ag-28Cu supersaturated solid solution exists at about 2θ=39° when the milling time is 30h. HRTEM images show that the grain sizes of as-prepared solid solutions have distributions from 10nm to 15nm. The interplanar spacing of (111) plane for fcc Ag-28Cu supersaturated solid solution is about 2.24Å. DSC measurement result indicates that the melting temperature of Ag-28Cu supersaturated solid solution is 783.8°C. The Ag(Cu) supersaturated solid solutions are in metastable state and they will be transformed into Ag-rich phase and Cu-rich phase simultaneously by annealing at 215°C- 415°C.

R&D of the Next Generation Safety Analysis Methods for Fast Reactors With New Computational Science and Technology: 5 — Study of Eutectic Reaction Between Metals: Classical Molecular Dynamics Approach

2008 ◽  
Author(s):  
Takahiro Ito
Keyword(s):  
Molecular Dynamics ◽  
Solid Solution ◽  
Melting Temperature ◽  
Eutectic Reaction ◽  
Melting Behavior ◽  
Atomic Fraction ◽  
Eutectic Melting ◽  
Classical Molecular Dynamics ◽  
Embedded Atom ◽  
Pure Cu

Molecular dynamics study on eutectic phenomena between two metal materials is performed for development of a new MPS-based code named ‘COMPASS’ [1] being developed for meso-scale analysis of core disruptive accidents in Sodium-cooled fast reactor. In this study, Cu-Ag system is simulated by classical molecular dynamics to provide knowledge on detailed mechanisms on the inception and extension of eutectic melting. Embedded Atom Method [2] which has been used in many studies associated with atomic behavior of metals is applied. First, melting temperature of solid solution of Cu-Ag binary system is investigated. The analytical result on the dependence of the melting temperature on the atomic fraction of Cu shows good agreement with the experiments. The melting behavior on the interface between two pure Cu and Ag slabs are then simulated. It is shown that the melting temperature at the interface is lowered depending on the local value of the atomic fraction there and is almost identical to that of solid solution with the corresponding atomic fraction.

THE COPPER/ARSENIC SYSTEM AND THE COPPER ARSENIDE MINERALS

1960 ◽  
Vol 38 (12) ◽  
pp. 2477-2481 ◽  
Author(s):  
R. D. Heyding ◽  
G. J. G. Despault
Keyword(s):  
Solid Solution ◽  
High Pressure ◽  
Approximate Formula ◽  
Text Structure ◽  
Intermediate Phases ◽  
Ε Phase ◽  
Polymorphic Forms ◽  
Copper Arsenide ◽  
Pressure Phase ◽  
Copper Arsenic

In addition to the α solid solution of arsenic in copper, three intermediate phases exist in the copper/arsenic system. The ε phase, stable only below ca. 340 °C, has the hexagonal A3 [Formula: see text] structure with a = 2.588, c = 4.226 Å, and the approximate formula Cu8As. The compound Cu3−xAs with 0 ≤ x ≤0.3, is trigonal, [Formula: see text]with a = 7.132, c = 7.304 Å at x = 0. This compound has no polymorphic forms between 200 °C and the melting point. The arsenic-rich compound Cu5−uAs2, with 0 ≤ u ≤ 0.1, melts incongruently at about 700 °C, and decomposes at 300 °C to arsenic and Cu3As. The structure has not been determined, but the powder diffraction pattern is recorded. The solubility of copper in arsenic appears to be negligible.It is suggested that the mineral α domeykite is a high-pressure phase, and that the mineral algodonite is a high-pressure modification of the ε phase. The mineral β domeykite is isostructural with Cu3As.

Mechanical Properties and Microstructure of Strip Casted Ag-27%Cu-25%Zn-3%Sn Brazing Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 485-488 ◽  
Author(s):  
Kee Ahn Lee ◽  
Sung Jun Kim ◽  
Moon Chul Kim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Microstructural Analysis ◽  
Mechanical Tests ◽  
Rich Phase ◽  
Aging Heat Treatment ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Twin Roll

This work sought to examine the suitability of twin roll strip casting for Ag-27%Cu- 25%Zn-3%Sn brazing alloy (BAg-7A) and to investigate the mechanical properties and microstructure of the strip. The effect of aging heat treatment on the properties was also studied. This new manufacturing process has applications in the production of the brazing alloy. XRD and microstructural analysis of the Ag-27%Cu-25%Zn-3%Sn strip represented eutectic microstructure of a Cu-rich phase and a Ag-rich matrix regardless of heat treatment. The results of mechanical tests showed tensile strength of 470MPa, a significant enhancement; and an 18% elongation of the twin roll casted strip, due mainly to the solid solution strengthening of Zn atoms (~20%) in the Cu-rich phases. Tensile results showed gradually decreasing strengths and increasing elongation with aging heat treatment. Microstructural evolution and fractography were also investigated and related to the mechanical properties.

Spinodal Decomposition in Fe-Cr Alloys

2011 ◽  
Vol 172-174 ◽  
pp. 443-448
Author(s):  
Orlando Soriano Vargas ◽  
Erika O. Avila Davila ◽  
Victor M. Lopez-Hirata ◽  
Maribel L. Saucedo-Muñoz
Keyword(s):  
Solid Solution ◽  
Mechanical Behavior ◽  
Spinodal Decomposition ◽  
Growth Kinetics ◽  
Supersaturated Solid Solution ◽  
Rich Phase ◽  
Hardening Behavior ◽  
Plate Shape ◽  
Kinetics Of ◽  
Preferential Alignment

The hardening behavior of precipitation was studied during aging of Fe-Cr alloys. This mechanical behavior is associated with the nanometric modulation structure of the coherent decomposed Fe-rich and Cr-rich phases formed by the spinodal decomposition of the supersaturated solid solution. The growth kinetics of spinodal decomposition was very slow and it increased during coarsening stage. The morphology of decomposed phases consisted of an interconnected irregular shape with no preferential alignment for short aging times and a further aging caused the change to a plate shape of the decomposed Cr-rich phase aligned in the <110> directions of the Fe-rich matrix. The rapid increase in hardness and embrittlement seem to be associated with the coherency and nanometer size of the spinodally-decomposed phases in the aged alloys.

Brazing of transparent polycrystalline Al2O3 and GH99 with the assistance of (Cu, Ni) solid solution cladding layer

2020 ◽  
Author(s):  
Bo Zhang ◽  
Lixia Zhang ◽  
Zhan Sun ◽  
Jicai Feng
Keyword(s):  
Solid Solution ◽  
Shear Strength ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Joint Shear Strength ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Solution Layer ◽  
Cu Foil ◽  
Pure Cu

Abstract In this study, pure Cu foil was firstly vacuum cladding on the GH99 alloy (GH99) surface to prepare a (Cu, Ni) solid solution layer. By varying the cladding temperatures, (Cu, Ni) solid solution layers with different Ni contents were achieved. The vacuum cladding process was then followed by vacuum brazing of the Cu-coated GH99 to transparent polycrystalline Al 2 O 3 (TPA). Typical microstructure of the TPA/Cu-cladding GH99 brazed joint was characterized. The effects of different cladding temperatures on microstructural evolution and mechanical response of the brazed joints were discussed. By varying the cladding temperature, different thickness of the reaction layer at the braze filler/TPA interfaces can be achieved, which shows a strong correlation with the mechanical performance of the brazed joint. The maximum shear strength of the brazed joint reached 103 MPa when the cladding temperature was 1105 ºC. Compared with the directly brazed joint, shear strength was improved by 472%.

scholarly journals Controlling the Isothermal Crystallization of Isodimorphic PBS-ran-PCL Random Copolymers by Varying Composition and Supercooling

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 17 ◽  
Author(s):  
Maryam Safari ◽  
Agurtzane Mugica ◽  
Manuela Zubitur ◽  
Antxon Martínez de Ilarduya ◽  
Sebastián Muñoz-Guerra ◽  
...  
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Polarized Light ◽  
Eutectic Point ◽  
Random Copolymers ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Butylene Succinate ◽  
Rich Phase ◽  
Spherulitic Growth

In this work, we study for the first time, the isothermal crystallization behavior of isodimorphic random poly(butylene succinate)-ran-poly(ε-caprolactone) copolyesters, PBS-ran-PCL, previously synthesized by us. We perform nucleation and spherulitic growth kinetics by polarized light optical microscopy (PLOM) and overall isothermal crystallization kinetics by differential scanning calorimetry (DSC). Selected samples were also studied by real-time wide angle X-ray diffraction (WAXS). Under isothermal conditions, only the PBS-rich phase or the PCL-rich phase could crystallize as long as the composition was away from the pseudo-eutectic point. In comparison with the parent homopolymers, as comonomer content increased, both PBS-rich and PCL-rich phases nucleated much faster, but their spherulitic growth rates were much slower. Therefore, the overall crystallization kinetics was a strong function of composition and supercooling. The only copolymer with the eutectic composition exhibited a remarkable behavior. By tuning the crystallization temperature, this copolyester could form either a single crystalline phase or both phases, with remarkably different thermal properties.

Effect of tin addition on the microstructure, wettability and mechanical properties of Cu–Mn–Ni braze fillers

2019 ◽  
Vol 33 (32) ◽  
pp. 1950392
Author(s):  
Mingyue Zhang ◽  
Song Zhang ◽  
Yuanxing Li ◽  
Minan Zhang ◽  
Jing Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Rich Phase ◽  
Melting Temperatures

A series of Cu–34Mn–6Ni–[Formula: see text]Sn (wt.%) braze fillers that were used for brazing stainless steel (SS) were prepared. The microstructures, melting temperatures, wettability and mechanical properties of the braze fillers were investigated. An Sn-rich phase was formed in braze fillers with an Sn content above 6 wt.% (including) because of the segregation performance of Sn. The melting temperatures of braze fillers decreased markedly with an increase in Sn content. The addition of 6 wt.% Sn resulted in the highest wettability of braze fillers on the SS. With an increase in Sn content, the tensile strength and hardness increased, whereas the plasticity and toughness of the braze fillers decreased owing to the solid solution and segregation of Sn.

Effects of some Parameters on Properties of Cu-Al2O3 Composite Materials Synthesized by Internal Oxidation Process

2019 ◽  
Vol 889 ◽  
pp. 38-42
Author(s):  
Ho Ky Thanh ◽  
Duc Duy Nguyen
Keyword(s):  
Solid Solution ◽  
Composite Materials ◽  
Internal Oxidation ◽  
Electrode Materials ◽  
Oxidation Process ◽  
Sintering Process ◽  
Micro Hardness ◽  
Xrd Patterns ◽  
Pure Cu ◽  
Cylindrical Samples

The Cu-Al2O3 composite materials applying for electrode materials were successfully synthesized by internal oxidation process. The process included steps: producing solid solution α-Cu[Al] and oxidizing completely solid solution α-Cu[Al] as powders, then adding pure Cu powders and mixing in planetary ball milling, the mixtures were compressed into cylindrical samples, reduced at 750°C in 3h and sintered at 950°C in 2h in reduction atmosphere. The XRD patterns showed that total Al in Cu-matrix were completely oxidized in range of 20¸25h. After reducing and sintering process, the final products were Cu-Al2O3 composite materials. The results showed that micro-hardness, porosity and compress strength of Cu-Al2O3 materials increased with increasing of Al2O3 content, which was the result of dispersion of the fined Al2O3 grains in Cu-matrix. When Al2O3 content was unchanged, the porosity of received materials decreased with increasing of compress pressure. Whereas, the electrical conductivity of Cu-Al2O3 composite materials decreased comparing with pure Cu and it decreased with increasing of Al2O3 content.

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