Features of the Two-Phase (α + α2) Structure Formation in the Ti–17 at % Al alloy

2020 ◽  
Vol 121 (8) ◽  
pp. 791-796
Author(s):  
A. A. Popov ◽  
K. I. Lugovaya ◽  
E. N. Popova ◽  
V. V. Makarov ◽  
M. A. Zhilyakova
Keyword(s):  
Structure Formation ◽  
Al Alloy ◽  
Two Phase

Diffusion of Zinc in Two-Phase Mg-Al Alloy

2007 ◽  
Vol 263 ◽  
pp. 189-194
Author(s):  
Ivo Stloukal ◽  
Jiří Čermák
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Effective Diffusion ◽  
Residual Activity ◽  
Diffusion Path ◽  
Al Alloy ◽  
Serial Sectioning ◽  
Two Phase ◽  
Interphase Boundaries ◽  
The Mean

Coefficient of 65Zn heterodiffusion in Mg17Al12 intermetallic and in eutectic alloy Mg - 33.4 wt. % Al was measured in the temperature region 598 – 698 K using serial sectioning and residual activity methods. Diffusion coefficient of 65Zn in the intermetallic can be written as DI = 1.7 × 10-2 m2 s-1 exp (-155.0 kJ mol-1 / RT). At temperatures T ≥ 648 K, where the mean diffusion path was greater than the mean interlamellar distance in the eutectic, the effective diffusion coefficient Def = 2.7 × 10-2 m2 s-1 exp (-155.1 kJ mol-1 / RT) was evaluated. At two lower temperatures, the diffusion coefficients 65Zn in interphase boundaries were estimated: Db (623 K) = 1.6 × 10-12 m2 s-1 and Db (598 K) = 4.4 × 10-13 m2 s-1.

Observation of planar stacking faults in a Ti-rich two-phase Ti-Al alloy after deformation at elevated temperatures

2000 ◽  
Vol 80 (1) ◽  
pp. 19-26 ◽  
Author(s):  
S. H. Chen ◽  
D. Mukherji ◽  
G. Schumacher ◽  
G. Frohberg ◽  
R.P. Wahi
Keyword(s):  
Elevated Temperatures ◽  
Stacking Faults ◽  
Al Alloy ◽  
Two Phase

Production, Properties and Application of Ultrafine-Grained Titanium Alloys

2016 ◽  
Vol 838-839 ◽  
pp. 294-301 ◽  
Author(s):  
Sergey Zherebtsov ◽  
Gennady Salishchev
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Titanium Alloys ◽  
Structure Formation ◽  
Temperature Interval ◽  
Two Phase ◽  
Homogeneous Microstructure ◽  
Wide Temperature Interval ◽  
Ultrafine Grained ◽  
Kinetics Of

Some features ofstructure, way of production and mechanical properties of titanium andtwo-phase titanium alloys with ultrafine-grained (UFG) microstructure werediscussed. Various methods of UFG structure formation was considered andoptimal conditions for attaining of a homogeneous microstructure with thesmallest grain size were determined. The kinetics of microstructure evolutionin titanium and two-phase titanium alloys during large (severe) plasticdeformation in a wide temperature interval and the mechanisms of ultrafinegrain formation were analyzed. The influence of grain size on static mechanicalproperties was determined. Significantly reduced temperatures of superplasticforming of the UFG conditions were shown. Some examples of practical applicationsof the UFG two-phase titanium alloys were discussed.

Microstructure and Mechanical Properties of Al Added Ni3(Si,Ti) Intermetallic Thin Sheets

2010 ◽  
Vol 654-656 ◽  
pp. 480-483
Author(s):  
Yasuyuki Kaneno ◽  
Yasunori Fujimoto ◽  
Takayuki Takasugi
Keyword(s):  
High Temperature ◽  
Single Phase ◽  
Thermomechanical Processing ◽  
Al Alloy ◽  
Thin Sheets ◽  
Intermetallic Alloys ◽  
Ordered Structure ◽  
Two Phase ◽  
Cold Rolled ◽  
High Temperature Tensile

The effect of Al addition on microstructures and tensile properties of cold-rolled Ni3(Si,Ti) intermetallic alloys with L12 ordered structure, which were fabricated through thermomechanical processing from arc-melted ingots, were investigated. Addition of 4 and 8 at.% Al to Ni3(Si,Ti) was conducted in two ways that Al substituted for Ti site and both for Ni and Ti sites, respectively. The alloys made by the former way showed a two-phase microstructure consisting of disordered fcc Ni solid solution dispersions in the L12 matrix, irrespective of Al contents, while the 4 at.% Al alloy made by the latter way exhibited an L12 single-phase microstructure. These alloys were successfully cold-rolled to thin sheets with a thickness of 200 μm except the 8 at.% Al alloy made by the latter way. For the thermomechanically processed 4 at.% Al alloys, high-temperature yield stress was higher in the alloy made by the latter way than in the alloy made by the former one, suggesting that the single-phase microstructure consisting of whole L12 ordered structure is favorable for high-temperature tensile property.

Metastable Two-Phase Field(A2+B2) in Co-Al-Fe and Co-Al Alloy Systems

2004 ◽  
Vol 449-452 ◽  
pp. 61-64 ◽  
Author(s):  
Takao Kozakai ◽  
Tadaaki Shikama ◽  
Toshiyuki Koyama ◽  
Minoru Doi
Keyword(s):  
Phase Field ◽  
Composition Gradient ◽  
Al Alloy ◽  
Limit Curve ◽  
Compositional Gradient ◽  
Two Phase ◽  
Transmission Electron ◽  
Phase Fields ◽  
Short Time ◽  
Alloy Systems

Precipitation of disordered bcc Co (A2) particles has been investigated in Co-rich B2 ordered Co-Al-Fe and Co-Al alloys by means of a macroscopic composition gradient method using a transmission electron microscope. When Co-Al-Fe ternary and Co-Al binary alloys were annealed at 823-1023K for a relatively short time, bcc disordered particles precipitated within B2 ordered matrix, followed by the formation of equilibrium fcc α-Co (A1) on the phase boundaries. The precipitation limit of metastable A2 phase was evaluated using the binary and ternary specimens with macroscopic compositional gradient. As a result, it was found that the limits are located within the equilibrium A1+B2 two-phase fields in both ternary and binary alloy systems, and that the limit curve on the isothermal section at 923K for Co-Al-Fe system successfully connects with the phase boundary of A2+B2 two-phase field at the Co-Fe binary side of the ternary system.

Submicrocrystalline Structure Formation in Ti and Ti-64 Alloy by Warm “abc” Deformation

2007 ◽  
Vol 551-552 ◽  
pp. 183-188 ◽  
Author(s):  
Sergey V. Zherebtsov ◽  
Sergey Mironov ◽  
Gennady A. Salishchev
Keyword(s):  
Grain Size ◽  
Titanium Alloy ◽  
Steady State ◽  
Mechanical Behavior ◽  
Structure Formation ◽  
Microstructure Evolution ◽  
Superplastic Flow ◽  
Steady State Flow ◽  
Two Phase ◽  
State Flow

Mechanical behavior and microstructure evolution of Ti and Ti-64 titanium alloy during warm “abc” deformation has been studied. The “abc” deformation was consisted of successive compression of a sample along three orthogonal directions. Mechanical behavior of each material was described by set of successive σ-ε curves combined into cumulative σ-Σε curve. Microstructure of Ti was found to be refined to a grain size of about 0.4 μm due to formation of deformation-induced boundaries within initial grains. Although a stage like steady state flow was observed at the cumulative σ-Σε curve such mechanical behavior was hardly associated with superplastic flow. In two-phase Ti-64 alloy the structure was found to be refined to a grain size of about 0.4 μm after warm “abc” deformation due to globularization α- and β-particles following breaking down of α-lamellar and β- layers. Microstructure refinement of the alloy was associated with softening and superplastic flow.

scholarly journals Induced by acoustic fieldsprocesses of structure formation in high-molecular media

2021 ◽  
Vol 9 (2) ◽  
pp. 128-143
Keyword(s):  
Structure Formation ◽  
Gas Bubbles ◽  
Well Logging ◽  
Acoustic Fields ◽  
Two Phase ◽  
Oil Saturation ◽  
Vibra Tions ◽  
Oil Processing ◽  
Dispersed Medium

The paper considers the mechanisms of destruction and synthesis of macromolecules, which can be stimulated by external acoustic fields in a two-phase, oil dispersed medium containing a large number of gas bubbles. It is assumed that the dynamics of these bub-bles depends on changes in the geometry of the flow and the excitation of sound vibra-tions in the flow. Particular attention is paid to the process of changing the density of a liquid due to the effect of an internal airlift in a liquid dispersed medium. Mechanically induced kinetic changes in macromolecules (destruction and synthesis of colloidal chains) can occur when bubbles collapse. These features can be used in oil processing and well logging to assess oil saturation of reservoirs.

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