Formation and coalescence of strain localized regions in ferrite phase of DP600 steels under uniaxial tensile deformation

2015 ◽  
Vol 623 ◽  
pp. 133-144 ◽  
Author(s):  
A. Alaie ◽  
J. Kadkhodapour ◽  
S. Ziaei Rad ◽  
M. Asadi Asadabad ◽  
S. Schmauder
Keyword(s):  
Tensile Deformation ◽  
Ferrite Phase ◽  
Uniaxial Tensile

scholarly journals A Flow Stress Model of 300M Steel for Isothermal Tension

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 252
Author(s):  
Rongchuang Chen ◽  
Shiyang Zhang ◽  
Xianlong Liu ◽  
Fei Feng
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Tensile Deformation ◽  
Flow Behavior ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Model Parameters ◽  
Average Deviation ◽  
Cross Sectional ◽  
300M Steel

To investigate the effect of hot working parameters on the flow behavior of 300M steel under tension, hot uniaxial tensile tests were implemented under different temperatures (950 °C, 1000 °C, 1050 °C, 1100 °C, 1150 °C) and strain rates (0.01 s−1, 0.1 s−1, 1 s−1, 10 s−1). Compared with uniaxial compression, the tensile flow stress was 29.1% higher because dynamic recrystallization softening was less sufficient in the tensile stress state. The ultimate elongation of 300M steel increased with the decrease of temperature and the increase of strain rate. To eliminate the influence of sample necking on stress-strain relationship, both the stress and the strain were calibrated using the cross-sectional area of the neck zone. A constitutive model for tensile deformation was established based on the modified Arrhenius model, in which the model parameters (n, α, Q, ln(A)) were described as a function of strain. The average deviation was 6.81 MPa (6.23%), showing good accuracy of the constitutive model.

scholarly journals An Experimental Study of the Tension-Compression Asymmetry of Extruded Ti-6.5Al-2Zr-1Mo-1V under Quasi-Static Conditions at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1299
Author(s):  
Chen Zhang ◽  
Dongsheng Li ◽  
Xiaoqiang Li ◽  
Yong Li
Keyword(s):  
High Temperature ◽  
Strain Hardening ◽  
Yield Stress ◽  
Mechanical Response ◽  
Tensile Deformation ◽  
Uniaxial Tensile ◽  
Tensile Direction ◽  
Stress Asymmetry ◽  
Static Conditions ◽  
Tension Compression Asymmetry

The tension-compression asymmetry (TCA) behavior of an extruded titanium alloy at high temperatures has been investigated experimentally in this study. Uniaxial tensile and compressive tests were conducted from 923 to 1023 K with various strain rates under quasi-static conditions. The corresponding yield stress and asymmetric strain hardening behavior were obtained and analyzed. In addition, the microstructure at different temperatures and stress states indicates that the extruded TA15 profile exhibits a significant yield stress asymmetry at different testing temperatures. The flow stress and yield stress during tension are greater than compression. The yield stress asymmetry decreases with the increase in temperature. The alloy also exhibits TCA behavior on the strain hardening rate. Its mechanical response during compression is more sensitive than tension. A dynamic recrystallization phenomenon is observed instead of twin generated in tension and compression under high-temperature quasi-static conditions. The grains are elongated along the tensile direction and deformed by about 45° along the compressive load axis. Finally, the TCA of Ti-6.5Al-2Zr-1Mo-1V (TA15) alloy is due to slip displacement. The tensile deformation activates basal <a>, prismatic <a> and pyramidal <c + a> slip modes, while the compressive deformation activates only prismatic <a> and pyramidal <c + a> slip modes.

Mechanical Properties and Strain Transfer Behavior of Molybdenum Ditelluride (MoTe2) Thin Films

2021 ◽  
pp. 1-31
Author(s):  
Shoieb Ahmed Chowdhury ◽  
Katherine Inzani ◽  
Tara Pena ◽  
Aditya Dey ◽  
Stephen M. Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Change ◽  
Density Functional ◽  
Mechanical Response ◽  
Interatomic Potential ◽  
Tensile Deformation ◽  
Random Search ◽  
Mechanical Strain ◽  
Uniaxial Tensile ◽  
Strain Transfer

Abstract Transition metal dichalcogenides (TMDs) offer superior properties over conventional materials in many areas such as in electronic devices. In recent years, TMDs have been shown to display a phase switching mechanism under the application of external mechanical strain, making them exciting candidates for phase change transistors. Molybdenum ditelluride (MoTe2) is one such material that has been engineered as a strain-based phase change transistor. In this work, we explore various aspects of the mechanical properties of this material by a suite of computational and experimental approaches. Firstly, we present parameterization of an interatomic potential for modeling monolayer as well as multilayered MoTe2 films. For generating the empirical potential parameter set, we fit results from Density Functional Theory calculations using a random search algorithm called particle swarm optimization. The potential closely predicts structural properties, elastic constants, and vibrational frequencies of MoTe2 indicating a reliable fit. Our simulated mechanical response matches earlier larger scale experimental nanoindentation results with excellent prediction of fracture points. Simulation of uniaxial tensile deformation by Molecular Dynamics shows the complete non-linear stress-strain response up to failure. Mechanical behavior, including failure properties, exhibits directional anisotropy due to the variation of bond alignments with crystal orientation. Furthermore, we show the deterioration of mechanical properties with increasing temperature. Finally, we present computational and experimental evidence of an extended c-axis strain transfer length in MoTe2 compared to TMDs with smaller chalcogen atoms.

Tensile Deformation Behavior of 5A90 Al-Li Alloy Sheet at Elevated Temperature

2011 ◽  
Vol 66-68 ◽  
pp. 70-75 ◽  
Author(s):  
Gao Shan Ma ◽  
Song Yang Zhang ◽  
Han Ying Wang ◽  
Min Wan
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Tensile Deformation ◽  
Alloy Sheet ◽  
Hot Forming ◽  
Uniaxial Tensile ◽  
Sensitivity Index ◽  
Tensile Deformation Behavior ◽  
Increasing Temperature

Uniaxial tensile deformation behavior of 5A90 aluminium-lithium alloy sheet is investigated in the hot forming with the temperature range of 200-450°C and strain rate range of 0.3×10-3-0.2×10-1s-1. It is found that the flow stress of 5A90 Al-Li alloy in uniaxial tension increase with increasing strain rate and decrease with increasing temperature, however, the tendency of total elongation is just the reverse, and the optimum forming temperature is 400°C. The strain rate sensitivity index (m-value) remarkably increases with increasing temperature for a given strain rate. It is shown that 5A90 Al-Li alloy sheet displays the sensitivity to the strain rate at elevated temperatures. For a given strain rate, the strain hardening index (n-value) decreases with increasing temperature, whereas the n-value increases above 350°C. The constitutive equation of stress, strain and strain rate for 5A90 Al-Li alloy at any temperature is obtained by fitting the experimental data, which gave a good flow stress model for the FEM simulation of hot forming.

High-resolution X-ray diffraction investigation on the evolution of the substructure of individual austenite grains in TRIP steels during tensile deformation

2014 ◽  
Vol 47 (3) ◽  
pp. 965-973 ◽  
Author(s):  
Romain Blondé ◽  
Enrique Jimenez-Melero ◽  
Richard Huizenga ◽  
Lie Zhao ◽  
Jonathan Wright ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
High Resolution ◽  
Tensile Deformation ◽  
Subgrain Size ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trip Steels ◽  
Austenite Grains

The martensitic transformation behaviour of the metastable austenite phase in low-alloyed transformation-induced plasticity (TRIP) steels has been studiedin situusing high-energy X-ray diffraction during deformation. The austenite stability during tensile deformation has been evaluated at different length scales. A powder diffraction analysis has been performed to correlate the macroscopic behaviour of the material to the observed changes in the volume phase fraction. Moreover, the austenite deformation response has been studied at the length scale of individual grains, where an in-depth characterization of four selected grains has been performed, including grain volume, local carbon concentration and grain orientation. For the first time, a high-resolution far-field detector was used to study the initial and evolving structure of individual austenite grains during uniaxial tensile deformation. It was found that the austenite subgrain size does not change significantly during tensile deformation. Most austenite grains show a complete martensitic transformation in a single loading step.

Synchrotron x-ray Study of Elastic Phase Strains in the Bulk of an Externally Loaded Cu/Mo Composite

1999 ◽  
Vol 590 ◽  
Author(s):  
A. Wanner ◽  
D.C. Dunand
Keyword(s):  
Plastic Deformation ◽  
Load Transfer ◽  
Tensile Deformation ◽  
Copper Matrix ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Rays ◽  
Synchrotron Source ◽  
Peak Broadening ◽  
The Matrix

ABSTRACTHigh-energy, high-flux x-rays from a third-generation synchrotron source were used to measure average elastic strains in the bulk of 1.5 mm thick composites consisting of a copper matrix reinforced with 7.5 vol.% molybdenum particles. From the evolution of lattice strains in both phases during uniaxial tensile deformation, the internal load transfer between phases and reinforcement damage were characterized during elastic and plastic deformation of the composite. The graininess of the diffraction rings, which is related to the Bragg peak broadening, was quantified as a function of applied stress and related to plastic deformation in the matrix.

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