A Thermo-Viscoplastic Constitutive Equation Based on Hyperbolic-Shape Thermo-Activated Barriers

1984 ◽  
Vol 106 (4) ◽  
pp. 331-336 ◽  
Author(s):  
Li-Lih Wang
Keyword(s):  
Constitutive Equation ◽  
Strain Rate ◽  
Present Model ◽  
Strain Rate Effects ◽  
Bcc Metals ◽  
Special Cases ◽  
Wide Range ◽  
Rate Effects ◽  
Simple Parameter ◽  
Good Agreement

A thermo-viscoplastic constitutive equation is proposed on the basis of thermoactivated mechanism with a spectrum of hyperbolic-shape barriers, suitable for a wide range of strain rate and temperature. Relations with other existing models or rate theories, which may be regarded a special cases of present model, are examined. Good agreement with experimental data for both fcc and bcc metals is shown. The activation volume is found dependent on temperature according to an exponential law. A simple parameter, which describes the equivalence between strain rate effects and temperature effects on flow stress, is suggested similar to Zener-Hollomon parameters

Temperature and Strain Rate Effects on Plastic Deformation of Titanium Alloys

2007 ◽  
Vol 539-543 ◽  
pp. 3619-3624 ◽  
Author(s):  
K. Ogawa
Keyword(s):  
Titanium Alloy ◽  
Strain Rate ◽  
Titanium Alloys ◽  
Tensile Deformation ◽  
Beta Titanium Alloy ◽  
Stress Strain ◽  
Strain Rate Effects ◽  
Wide Range ◽  
Rate Effects ◽  
The Impact

Since titanium alloys are the most promising structural materials for the high velocity vehicles, the impact tensile strength of the materials is presently investigated. Three kinds of aging treatments on the beta-titanium alloy were performed, and the tensile deformation behaviors were identified in the wide range of the temperature and the strain rate. The stress－strain relations of the titanium alloy significantly depend on the temperature and the strain rate investigated. Thermally activated process concept was applied to explain the experimental results, and the stress-strain relations at high strain rates were well understood with taking account of adiabatic heating effect. It has been found that the stress-strain curves depend on the microstructures, while the temperature and the strain rate effects are almost independent of the different aging treatments.

Strain Rate Effects on Mechanical Stability of Retained Austenite in TRIP Sheet Steels

2006 ◽  
Author(s):  
Ildong Choi ◽  
Dongmin Son ◽  
Sung-joon Kim ◽  
David K. Matlock ◽  
John G. Speer
Keyword(s):  
Strain Rate ◽  
Retained Austenite ◽  
Mechanical Stability ◽  
Strain Rate Effects ◽  
Sheet Steels ◽  
Rate Effects
Sign in / Sign up

Export Citation Format

Share Document