scholarly journals Effect of Plastic Deformation on the Activation Energy for Precipitation of S' Phase in Al2024 Alloy

2020 ◽  
Vol 26 (S2) ◽  
pp. 2888-2889
Author(s):  
J.C. Guía-Tello ◽  
C.G. Garay-Reyes ◽  
H. M. Medrano-Prieto ◽  
M.A. Ruiz-Esparza-Rodriguez ◽  
M.C. Maldonado-Orozco ◽  
...  
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
S Phase ◽  
Al2024 Alloy

scholarly journals PLASTIC DEFORMATION OF THICK-WALLED SNOW-ICE CYLINDERS UNDER HYDROSTATIC PRESSURE

1962 ◽  
Vol 40 (10) ◽  
pp. 1310-1318 ◽  
Author(s):  
H. H. G. Jellinek
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
Hydrostatic Pressure ◽  
Strain Rate ◽  
Plastic Flow ◽  
Constant Pressure ◽  
Circumferential Stress ◽  
Sine Function ◽  
Kcal Mole ◽  
Flow Process

The results of experiments on the plastic deformation of hollow snow-ice cylinders, closed at one end, as a function of circumferential stress and temperature are discussed. Data are graphed on deformation as a function of time for a snow-ice cylinder under 7.03 and 14.06 kg/cm2 hydrostatic pressure at −4.5 °C, deformation as a function of hydrostatic pressure from 2.11 to 7.03 kg/cm2, and deformation as a function of temperature at a constant pressure of 10.55 kg/cm2. The natural strain rate of closure at constant circumferential stress and temperature was a constant, which varied with circumferential stress as a sine function and was "exponentially dependent on temperature, with an activation energy of 14.1 kcal/mole at an average circumferential stress of 3.1 kg/cm2. The experiments agree well with an earlier interpretation of the plastic flow process representing flow between grain boundaries.

Effect of Zr on Structure and Resistance to Intergranular Corrosion of Severely Deformed 2024 Aluminum Alloy

2019 ◽  
Vol 31 ◽  
pp. 35-42
Author(s):  
Stanislav Krymskiy ◽  
Rafis Ilyasov ◽  
Elena Avtokratova ◽  
Oleg Sitdikov ◽  
Anastasia Khazgalieva ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
Intergranular Corrosion ◽  
Artificial Aging ◽  
Volume Fraction ◽  
S Phase ◽  
2024 Aluminum Alloy ◽  
Excess Phases ◽  
Electrochemical Potentials

Effects of severe plastic deformation by isothermal сryorolling with a strain of e~2 and subsequent natural and artificial aging on the structure and resistance to intergranular corrosion (IGC) of the preliminary quenched 2024 aluminum alloy of standard and Zr modified compositions were investigated. Increasing the temperature of aging leads to decreasing the alloy IGC resistance due to precipitation of more stable strengthening S-phase (Al2CuMg), rising difference of electrochemical potentials at grain and subgrain boundaries. Zr additions, оn the opposite, significantly increased the alloy IGC resistance in both naturally and artificially aged conditions, reducing its depth and intensity. The main structural factor, influencing the alloy corrosion behavior, is excess phases: their composition, volume fraction and distribution.

Characteristics of Plasticity and Microstructure of Hot Forming Magnesium Alloys Mg-Al-Zn Type / Charakterystyki Plastycznosci I Mikrostruktura Odkształcanych Na Goraco Stopów Magnezu Typu Mg-Al-Zn

2013 ◽  
Vol 58 (1) ◽  
pp. 151-156 ◽  
Author(s):  
D. Kuc ◽  
E. Hadasik ◽  
I. Schindler ◽  
P. Kawulok ◽  
R. Sliwa
Keyword(s):  
Activation Energy ◽  
Plastic Deformation ◽  
Magnesium Alloys ◽  
Hot Forming ◽  
Aluminium Content ◽  
Test Results ◽  
Compression Tests ◽  
Hot Plastic Deformation ◽  
Twin Formation ◽  
Reduction Of Area

The paper presents analysis of plasticity characteristics and microstructure of magnesium alloys for hot plastic treatment with different aluminium content (3÷8%). Tests were conducted for assessment of susceptibility of tested alloys to hot plastic deformation. A tensile test was run in temperature from 250 to 450°C. Based on the results, ultimate tensile strength (UTS) and reduction of area (Z) were determined for samples. Conducted compression tests allowed to specify the flow stress and microstructure changes after deformation. The activation energy in hot forming was determined for investigated alloys. The parameters of the process where flow is significantly influenced by twin formation in microstructure were determined. A varied plasticity of tested alloys was found depending on aluminium content. Test results will be useful in development of forging technology of selected construction elements which serve as light substitutes for currently used materials.

Electromagnetoelasticity Effect in Silicon

2017 ◽  
Vol 269 ◽  
pp. 78-89 ◽  
Author(s):  
Arkady A. Skvortsov ◽  
Andrey V. Karizin
Keyword(s):  
Magnetic Field ◽  
Activation Energy ◽  
Plastic Deformation ◽  
Electric Current ◽  
Interaction Energy ◽  
Single Crystals ◽  
Exposure Time ◽  
Constant Magnetic Field ◽  
Linear Defects ◽  
P Type

The paper is devoted to the study of the magnetostimulated dynamics of dislocations in silicon and the influence of electric current on this process. As a result of the conducted studies, it was found that preliminary exposure of n-and p-type silicon single crystals in a constant magnetic field (B = 1 T, exposure time up to 30 minutes) leads to an increase in mobility of dislocation segments in them during plastic deformation of samples (Т=675оС, σ=60–100 MPa, t=45–60 minutes). The quadratic dependence of the dislocation ranges on the induction of a constant magnetic field was found on the samples studied. A decrease in the activation characteristics of the process of displacement of linear defects during the flow of electric current during deformation is also detected: the transmission of electric current helps to reduce the activation energy of the process from 2.2± 0.2 eV to 0.7±0.1 eV. The observed changes are attributed to a decrease in the interaction energy of linear defects with dislocation stoppers based on the dopant.

Viscosity Controlled Interdiffusion in Nitriding

2017 ◽  
Vol 10 ◽  
pp. 28-38
Author(s):  
Katarzyna Tkacz-Śmiech ◽  
Bogusław Bożek ◽  
Lucjan Sapa ◽  
Marek Danielewski
Keyword(s):  
Plastic Deformation ◽  
Dynamic Pressure ◽  
S Phase ◽  
Diffusion Saturation ◽  
Concentration Profiles ◽  
New Approach ◽  
Austenite Steel ◽  
Basic Equations ◽  
Model Formation ◽  
Nitride Zone

This works presents new approach to model formation of expanded austenite (S-phase) during nitriding in plasma conditions. Diffusion saturation of the substrate (iron or austenite steel) is treated as interdiffusion of nitrogen and iron that involves stresses and plastic deformation and is based on the Darken scheme. It is argued that S-phase growing at nitriding behaves as elasto-viscous Maxwell solid. During the process, in the nitride zone, the dynamic pressure appears, which is related to Darken drift and depends on metal viscosity. Basic equations are formulated and discussed. The formula for drift is derived. Exemplary results, i.e. concentration profiles, dynamic pressure and dilatation of the sample during the process, are presented. Concentration profiles confirm existence of characteristic plateau like zone in the surface adjacent zone.

Plastic deformation in an Al–Cu–Fe icosahedral alloy

1993 ◽  
Vol 8 (6) ◽  
pp. 1199-1202 ◽  
Author(s):  
J.E. Shield ◽  
M.J. Kramer ◽  
R.W. McCallum
Keyword(s):  
Electron Microscopy ◽  
Activation Energy ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
Steady State ◽  
Quasi Steady State ◽  
High Temperature Creep ◽  
Steady State Regime ◽  
Transmission Electron ◽  
State Regime

Al—Cu—Fe quasicrystalline alloys have been deformed by high-temperature creep between 680 and 740 °C. Deformations greater than 30% were achieved without cracking. Analysis of the data in the quasi-steady state regime reveals power law behavior with a stress exponent of 2.5. The activation energy for deformation was determined to be 640 ± 20 kJ/mole in the temperature region investigated. Transmission electron microscopy revealed lamellar defects which appear similar to twins.

Evolution of Structure and Phase Composition of Aluminum Alloy under Severe Plastic Deformation

2014 ◽  
Vol 880 ◽  
pp. 179-183
Author(s):  
Evgeniy V. Naydenkin ◽  
Konstantin V. Ivanov ◽  
Gennadiy E. Rudenskii
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Severe Plastic Deformation ◽  
S Phase ◽  
High Thermal Stability ◽  
Ultrafine Grained ◽  
Evolution Of Structure ◽  
Thermal Stability Of

The paper shows that high thermal stability of the ultrafine-grained structure of aluminum alloy produced by severe plastic deformation is related to S-phase particles. The sequence of phase transformations of zirconium-doped ultrafine-grained alloy Al-Mg-Li in heating is revealed. The paper also determines temperatures at which depending on crystal structure two types of S-phase particles can form.

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