scholarly journals Formation of Intermediate Phases and Supersaturated Solid Solution in Al-Cu System during Diffusion

2018 ◽  
Vol 383 ◽  
pp. 31-35 ◽  
Author(s):  
Alexey Rodin ◽  
Nataliya Goreslavets
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
High Temperature ◽  
Chemical Composition ◽  
Low Temperature ◽  
Supersaturated Solid Solution ◽  
Diffusion Processes ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Intermediate Phases

The study of diffusion processes in the aluminum - copper system was carried out at the temperature 350 and 520 °C. Special attention was paid on the chemical composition of the system near Al/Cu interface. It was determined that the intermediate phases in the system, corresponding to the equilibrium phase diagram, were not formed at low temperature. At high temperature the intermediate phases forms starting with Cu - rich phases. In both cases supersaturated solid solution of copper in aluminum could be observed near the interface.

Intermetallic Formation in the Aluminum–Copper System

2003 ◽  
Vol 10 (04) ◽  
pp. 677-683 ◽  
Author(s):  
E. B. Hannech ◽  
N. Lamoudi ◽  
N. Benslim ◽  
B. Makhloufi
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
Solid Solution ◽  
Intermetallic Layer ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Diffusion Couples ◽  
Intermetallic Formation ◽  
Parabolic Law ◽  
Scanning Electron

Intermetallic formation at 425°C in the aluminum–copper system has been studied by scanning electron microscopy using welded diffusion couples. Several Al–Cu phases predicted by the equilibrium phase diagram of the elements and voids taking place in the diffusion zone have been detected in the couples. The predominant phases were found to be Al 2 Cu 3 and the solid solution of Al in Cu, α. The growth of the intermetallic layer obeyed the parabolic law.

Steady-State Dynamic Phase Diagram Calculation of U-Ti and U-V Binary System under Irradiation

2020 ◽  
Vol 993 ◽  
pp. 996-1003
Author(s):  
Yong Lu ◽  
Zheng Jiang ◽  
Qiao Qiao Tang ◽  
Cui Ping Wang ◽  
Xing Jun Liu
Keyword(s):  
Phase Diagram ◽  
Steady State ◽  
Binary System ◽  
Low Temperature ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Enhanced Diffusion ◽  
Dynamical Phase ◽  
Irradiation Intensity ◽  
Phase Relationships

In this paper, by considering the irradiation-enhanced diffusion, a combination of effective free energy model and the thermodynamic model was used for studying the phase relationships in the U-Ti and U-V binary system under irradiation. The steady-state dynamical phase diagrams of U-Ti and U-V binary alloys under different irradiation intensities were calculated and compared with the conventional thermodynamic equilibrium phase diagram. The calculated results show that under irradiation the high-temperature stable (βTi, γU) and (γU,V) phases were stabilized at relatively low temperature resulting in invariant reactions at relatively low temperature. In addition, with the increase of the irradiation intensity, the temperature of the invariant reactions increased, and the phase regions of the (βTi, γU) and (γU,V) also increased.

Key Program for Non-Equilibrium Phase Diagram of Ni 1 Type Steel

2011 ◽  
Vol 204-210 ◽  
pp. 1357-1361 ◽  
Author(s):  
Qing Hua Zou ◽  
Sheng Zhong Zou
Keyword(s):  
Phase Diagram ◽  
Chemical Composition ◽  
Structural Steel ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Air Cooling ◽  
Lever Rule ◽  
Dynamic Phase ◽  
New Type ◽  
Non Equilibrium

The practical air-cooling new-type dynamic phase diagram and nonequilirium lever rule of Ni 1 structural steel was established, and the relevant structure and chemical composition were analyzed, which can be used in practical production. The computer programs for drawing binary non-equilibrium phase diagram of Ni type structural steel have designed.

scholarly journals Early stages of solid state reactions: insights from micro-XRD and XAS

2014 ◽  
Vol 70 (a1) ◽  
pp. C1519-C1519
Author(s):  
Serena Tarantino ◽  
Paolo Ghigna ◽  
Elisabetta Achilli ◽  
Sonia Pin ◽  
Michele Zema ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Solid State ◽  
Equilibrium Phase ◽  
Experimental System ◽  
Equilibrium Phase Diagram ◽  
Solid State Reactions ◽  
Reactive System ◽  
X Ray ◽  
Early Stages ◽  
Intermediate Phases

The mechanism of a solid state reaction in its early stages can be explored by investigating the time evolution of a model reactive system made of a thin layer of one reagent deposited onto a single crystal slab of the other reagent. Insights can be retrieved by comparing results at both local and long length scales obtained with films of different thicknesses and deposited onto different crystal orientations. In particular, reaction between ZnO and Al2O3has been chosen, as the spinel-forming reactions have been and still remain a model experimental system for investigating solid state reactions and because in the ZnO/Al2O3phase diagram, spinel is the only stable compound. The reaction initial steps have been investigated by using synchrotron X-ray diffraction, atomic force microscopy and X-ray absorption spectroscopy at the Zn-K edge starting from zincite films deposited onto (110)-, (012)-, (001)-oriented corundum single crystals [1,2]. The reaction eventually yields ZnAl2O4spinel but via a complex mechanism involving side and intermediate non-equilibrium compounds that do not appear in the equilibrium phase diagram of the pseudo-binary system. Spinel, when occurs, is polycrystalline at the end but initially forms with a few preferred orientations. Intermediate phases form before and in parallel with the growth of the spinel. Their number, composition, structure and kinetic role strongly depend on substrate orientation and film thickness. A more detailed understanding of the reactivity can be inferred by comparing EXAFS results to those of grazing incidence diffraction experiments of the films deposited on the (001) face of Al2O3and heat-treated at 10000C for different lengths of time. Information on the structure of the intermediate phases is given and results are discussed by comparing different films thickness to clarify the role of interfacial free energy and crystallographic orientation.

Self-propagating high-temperature synthesis of TiC and NbC by mechanical alloying

1995 ◽  
Vol 10 (12) ◽  
pp. 3129-3135 ◽  
Author(s):  
Z.G. Liu ◽  
L.L. Ye ◽  
J.T. Guo ◽  
G.S. Li ◽  
Z.Q. Hu
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
Mechanical Alloying ◽  
Heat Release ◽  
Milling Time ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram ◽  
Temperature Synthesis ◽  
High Temperature Reaction ◽  
High Temperature Synthesis

Titanium and niobium carbides have been synthesized through self-propagating high-temperature reaction by mechanically alloying the elemental powder mixtures. It is found that this reaction is very similar to the conventional self-propagating high-temperature synthesis (SHS) process, but the ignition of the reaction is identified to be the mechanical collisions instead of heating the materials. Analysis of the products reveals that the final products of the Ti-C system are in good agreement with the equilibrium phase diagram, showing less relation with the alloying process. The decrease of the C content shortens the milling time prior to the SHS reaction of TiC by promoting the intimate mixing of the components, but lowers the heat release of the reaction and makes the propagation of the reaction more slowly. The SHS reaction during the mechanical alloying of the Nb-C system shows little difference, but the decrease of the C content can hardly influence the milling time prior to the reaction. By lowering the heat release of the SHS reaction of NbC, it lowers the reaction propagating rate. Mechanical alloying Nb50C50 and Nb55C45 results in the formation of NbC, while mechanical alloying Nb60C40 results in NbC + Nb instead of NbC + Nb2C according to the phase diagram. It was attributed to the fact that the rapid SHS reaction favors the formation of NbC, but hinders the occurrence of Nb2C phase through slow diffusion between NbC and the residual Nb. The measurement of the lattice parameters of TiC and NbC for different composition affirms the observed results. The particle sizes of obtained TiC and NbC are very fine at around or even less than 1 μm.

scholarly journals Microstructural Evolution of Mo-Si-B Ternary Alloys through Heat Treatment at 1800°C

2011 ◽  
Vol 278 ◽  
pp. 527-532 ◽  
Author(s):  
Kyosuke Yoshimi ◽  
Soeng Ho Ha ◽  
Kouichi Maruyama ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Heat Treatment ◽  
Phase Diagram ◽  
Solid Solution ◽  
Microstructural Evolution ◽  
Alloy Composition ◽  
Equilibrium Phase ◽  
Secondary Phase ◽  
Equilibrium Phase Diagram ◽  
The Other ◽  
Ternary Alloys

First of all, the as-cast microstructures of Mo-rich Mo-Si-B ternary alloys were investigated around the triple junction point of the primary Mo solid solution, Mo5SiB2 and Mo2B in this work, based on the liquidus projections of the Mo-Si-B system which have been reported in earlier studies. Subsequently, their microstructural evolution through heat treatment was investigated. Since Mo2B crystallizes out during solidification into a primary or secondary phase even though the alloy composition lies in the triangle of Mo-Mo5SiB2-Mo3Si in the Mo-Si-B equilibrium phase diagram, the as-cast microstructures include the non-equilibrated Mo2B in wide compositional ranges. However, Mo2B was completely decomposed during heat treatment at 1800 °C for 24 h and this contributed to the development of homogeneous, fine microstructures. On the other hand, since Mo2B was not decomposed perfectly during 24 h of 1600 °C heat treatment, as-cast microstructures largely remained. Therefore, it is realized that the heat treatment at 1800 °C is necessary to obtain well-developed microstructures of Mo-Si-B alloys.

Equilibrium phase diagram of polystyrene and 8CB

1999 ◽  
Vol 37 (15) ◽  
pp. 1841-1848 ◽  
Author(s):  
Farida Benmouna ◽  
Abdelylah Daoudi ◽  
Fr�d�rick Roussel ◽  
Jean-Marc Buisine ◽  
Xavier Coqueret ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Equilibrium Phase ◽  
Equilibrium Phase Diagram
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