Determination of flow stress: Part 1 constitutive equation for aluminium alloys at elevated temperatures

1979 ◽  
Vol 6 (1) ◽  
pp. 215-223 ◽  
Author(s):  
T. Sheppard ◽  
D. S. Wright
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Aluminium Alloys ◽  
Elevated Temperatures

Constitutive Analysis of Ni-Base Superalloy Hastelloy X under Hot Compression Based on Thermodynamics

2012 ◽  
Vol 252 ◽  
pp. 73-76
Author(s):  
Horng Yu Wu ◽  
Hsu Cheng Liu ◽  
Feng Jun Zhu ◽  
Chui Hung Chiu
Keyword(s):  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Hot Deformation ◽  
Elevated Temperatures ◽  
Flow Behavior ◽  
Dislocation Creep ◽  
Hastelloy X ◽  
Constitutive Analysis ◽  
Base Superalloy

Hot deformation characteristics of Hastelloy X Ni-base superalloy were investigated at elevated temperatures. Hot compressive tests were carried out in the temperature and strain rate ranges from 900 to 1150 °C and 0.001 to 1 s–1, respectively. The constitutive equation relating flow stress, temperature, and strain rate was obtained based on the peak stresses. The flow behavior showed that the softening mechanisms were related to the dynamic recovery (DRV) and dynamic recrystallization (DRX). The flow stress of Hastelloy X was fitted well by the constitutive equation of the hyperbolic sine function. The constitutive analysis suggested that the hot deformation mechanism of the Hastelloy X was dislocation creep.

scholarly journals Hot Deformation Behavior and Processing Maps of a New Ti-6Al-2Nb-2Zr-0.4B Titanium Alloy

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2456
Author(s):  
Zhijun Yang ◽  
Weixin Yu ◽  
Shaoting Lang ◽  
Junyi Wei ◽  
Guanglong Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Deformation Mechanism ◽  
Power Dissipation ◽  
Hot Deformation ◽  
Dissipation Rate ◽  
Dynamic Recovery ◽  
Processing Maps ◽  
Temperature Range

The hot deformation behaviors of a new Ti-6Al-2Nb-2Zr-0.4B titanium alloy in the strain rate range 0.01–10.0 s−1 and temperature range 850–1060 °C were evaluated using hot compressing testing on a Gleeble-3800 simulator at 60% of deformation degree. The flow stress characteristics of the alloy were analyzed according to the true stress–strain curve. The constitutive equation was established to describe the change of deformation temperature and flow stress with strain rate. The thermal deformation activation energy Q was equal to 551.7 kJ/mol. The constitutive equation was ε ˙=e54.41[sinh (0.01σ)]2.35exp(−551.7/RT). On the basis of the dynamic material model and the instability criterion, the processing maps were established at the strain of 0.5. The experimental results revealed that in the (α + β) region deformation, the power dissipation rate reached 53% in the range of 0.01–0.05 s−1 and temperature range of 920–980 °C, and the deformation mechanism was dynamic recovery. In the β region deformation, the power dissipation rate reached 48% in the range of 0.01–0.1 s−1 and temperature range of 1010–1040 °C, and the deformation mechanism involved dynamic recovery and dynamic recrystallization.

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