Compressive behavior of liquid phase sintered 90 W-7Ni-3Fe heavy alloy at high temperature and low strain rate condition

2018 ◽  
Vol 76 ◽  
pp. 149-157 ◽  
Author(s):  
Yang Yu ◽  
Chaoyuan Ren ◽  
Wencong Zhang
Keyword(s):  
High Temperature ◽  
Liquid Phase ◽  
Strain Rate ◽  
Heavy Alloy ◽  
Compressive Behavior ◽  
Rate Condition ◽  
Strain Rate Condition ◽  
Low Strain Rate

Cavity of Al-Cu-Mg Alloy during Superplastic Deformation

2007 ◽  
Vol 551-552 ◽  
pp. 645-650
Author(s):  
Min Wang ◽  
Hong Zhen Guo ◽  
Y.J. Liu
Keyword(s):  
Strain Rate ◽  
Grain Boundaries ◽  
Superplastic Deformation ◽  
Room Temperature ◽  
Mg Alloy ◽  
Deformation Condition ◽  
Second Phase ◽  
Rate Condition ◽  
Second Phase Particles ◽  
Strain Rate Condition

According to the characteristic of appearing cavitation in the metals during superplastic deformation, the influence of strain rate on cavity evolvement, the influence of cavity on superplastic deformation capability, and the formation, development process of cavity were investigated for Al-Cu-Mg alloy (i.e. coarse–grained LY12). The results show that: ①The pore nucleation occurs not only at triangle grain boundaries, but also along nearby the second phase particles, and even within grains. The cavities at the triangle grain boundaries are present in V-shape, others near the second phase particles and within grains are present in O-shape. These cavities may result from disharmony slippage of grain boundaries. ②The tendency of cavity development decreases with increasing of strain-rate. In lower strain-rate condition, though Al-Cu-Mg alloy has better superplasticity, many big cavities in the specimen may reduce the room temperature properties of the alloy. In higher strain-rate condition, Al-Cu-Mg alloy has certain superplasticity and room temperature properties as well as few cavities forming. By analyzing, viscous layer on grain boundaries is very thin and grain sizes can be refined during their extruding and rotating each other in higher strain-rate superplastic deformation condition. ③Growth and coalescence of cavity are the main reason of the superplastic fracture of Al-Cu-Mg alloy. And small and a certain amount of cavities with dispersion and independence state are very useful to crystal boundary slippage.

A New Constitutive Model Describing the Plastic Flow of Metals: Application to the AA6082 Aluminum Alloy

2013 ◽  
Vol 585 ◽  
pp. 59-66 ◽  
Author(s):  
Mohamad El Mehtedi ◽  
Samer El Mohtadi ◽  
Stefano Spigarelli
Keyword(s):  
Aluminum Alloy ◽  
High Temperature ◽  
Strain Rate ◽  
Plastic Flow ◽  
Temperature Regime ◽  
High Strain ◽  
Constitutive Relationship ◽  
Constitutive Analysis ◽  
Solute Atoms ◽  
Low Strain Rate

A new constitutive relationship based on the combination of the Garofalo and Hensel-Spittel equations has been developed and successfully used to model the plastic flow of a AA6082 aluminum alloy. Two regimes of temperature and strain rate were identified: the constitutive analysis suggested that in the low strain rate/high temperature regime, deformation was controlled by viscous glide of dislocations in atmospheres of Mg solute atoms, while in the high strain rate/ low temperature regime, deformation was controlled by climb.

scholarly journals High-Temperature Deformation Behaviors of the C-Doped and N-Doped High Entropy Alloys

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1517
Author(s):  
Hailong Yi ◽  
Yifan Zhang ◽  
Renyi Xie ◽  
Mengyuan Bi ◽  
Daixiu Wei
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Flow Behavior ◽  
Temperature Deformation ◽  
Cubic Phase ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Entropy ◽  
Recrystallization Mechanism ◽  
Low Strain Rate

High entropy alloys (HEAs) containing multi-principal metallic constituents have attracted much attention. A good understanding of their hot-deformation behavior and recrystallization mechanism is the prerequisite for microstructures tuning and for optimizing mechanical performance. Here, the flow behavior and recrystallization mechanism of the N-doped and C-doped face-centered cubic phase HEAs are produced at high temperatures by hot-compression at 1123–1273 K, with strain rates of 0.1–0.001 s−1. Constitutive equations were successfully constructed to reveal flow behavior, and stress-strain curves were predicted using strain compensated polynomial functions. Discontinuous and continuous dynamic recrystallization proceeded concurrently when compressed at a low temperature and high strain rate, whereas discontinuous recrystallization, which occurs at primary grain boundaries, became predominant at a high temperature and low strain rate, significantly contributing to the refinement and homogenization of the grains. For this reason, a relatively high temperature and a low strain rate, in which the recrystallized grains exhibit equiaxed morphology and very weak texture, are more suitable for refining grains. The average size of the grains was approximately 10 μm. This study sheds light on grain optimization and mechanical properties through thermomechanical processing.

Experimental study and prediction of deformation behavior of low carbon steel at low strain rate and high temperature

2013 ◽  
Vol 58 (10) ◽  
pp. 940-945 ◽  
Author(s):  
Wei ZHOW ◽  
GuiNan ZHANG ◽  
Ying XIA ◽  
TongBin SHAO ◽  
Xue Fei CHEN ◽  
...  
Keyword(s):  
Experimental Study ◽  
High Temperature ◽  
Carbon Steel ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Low Strain Rate

High-Temperature Deformation Behavior of the γ Alloy Ti-48Ai-2Cr-2Nb

1990 ◽  
Vol 213 ◽  
Author(s):  
Donald S. Shih ◽  
Gary K. Scarr
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
True Strain ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Compression Tests ◽  
Uniform Deformation ◽  
Good Workability ◽  
Low Strain Rate

ABSTRACTThe hot-workability of a two-phase (γ+α2) alloy, Ti-48A1-2Cr-2Nb, has been studied by conducting isothermal compression tests to 0.8 true strain over the temperature range of 975–1200°C at strain rates between 1×l0−1 and 3×10−3s−1. A deformation map showing temperature, strain rate, soundness of deformation, and isostress contours was constructed. Good workability is found from the low temperature/low strain rate regime to combinations of high temperature and either high or low strain rate. The upper-limit flow stress for good workability is between 450 and 500 MPa. Deformation induced softening occurs at all conditions. SEM and TEM examinations of the deformed specimens reveal that non-uniform deformation takes place at all strain rates, but cracking occurs mostly at high strain rates (e.g. 1×10−1s−1), especially combined with low temperatures. The cracking appears to progress primarily along γ/α2interfaces. It is thought that non-uniform deformation develops channels of shear bands, which in turn promote localized recrystallization, thus accommodating higher strains.

A Constitutive Model for Strain-Induced Crystallization in Poly(ethylene terephthalate) (PET) during Finite Strain Load-Hold Simulations

2005 ◽  
Vol 128 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Rebecca B. Dupaix ◽  
Dwarak Krishnan
Keyword(s):  
Constitutive Model ◽  
Strain Rate ◽  
Complex Loading ◽  
Deformation Condition ◽  
Loading Conditions ◽  
Rate Condition ◽  
Strain Induced Crystallization ◽  
Strain Rate Condition ◽  
Poly Ethylene ◽  
Induced Crystallization

Recently, a hyperelastic-viscoplastic constitutive model was developed for PET and the noncrystallizing copolymer PETG (R. B. Dupaix, Ph.D. thesis, MIT, 2003). The materials were found to behave very similarly under monotonic loading conditions and the single constitutive model was able to capture both materials’ behavior. However, differences were observed upon unloading, and it is expected that additional differences would be observed under more complex loading conditions. Here their behavior is investigated under nonmonotonic loading conditions, specifically under load-hold conditions. The model of Dupaix and Boyce (R. B. Dupaix, Ph.D. thesis, MIT, 2003) is modified to include Ahzi’s upper-bound model for strain-induced crystallization [Ahzi et al., Mech. Mater., 35(12), pp. 1139–1148 (2003)]. The crystallization model is adapted to include criteria for the onset of strain-induced crystallization which depend on strain rate and level of deformation. The strain-rate condition prevents crystallization from beginning prior to the deformation process slowing significantly. The level-of-deformation condition delays crystallization until the material has deformed beyond a critical level. The combined model demonstrates differences in behavior between PET and PETG during complex loading situations, indicating its ability to capture the fundamental criteria for the onset of strain-induced crystallization.

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