Simulation of the Variation of Strain Rates During a Rolling Pass in Compression Tests

1989 ◽  
Vol 111 (4) ◽  
pp. 372-377 ◽  
Author(s):  
F. Wang ◽  
Y. Hwu ◽  
J. G. Lenard
Keyword(s):  
Strain Rate ◽  
True Strain ◽  
Constitutive Behavior ◽  
Strain Rates ◽  
Compression Tests ◽  
True Strain Rate ◽  
Rolling Pass ◽  
Constant True Strain Rate ◽  
Strain Rate Compression

A Nb-V steel’s response to constant true strain rate compression was compared to its behavior when the strain rate varied as during a rolling pass. The constitutive behavior during the two types of tests was found not to differ in a significant manner.

scholarly journals Constitutive Behavior of an AA4032 Piston Alloy with Cu and Er Additions upon High-Temperature Compressive Deformation

2019 ◽  
Vol 51 (1) ◽  
pp. 467-481
Author(s):  
Suwaree Chankitmunkong ◽  
Dmitry G. Eskin ◽  
Chaowalit Limmaneevichitr
Keyword(s):  
Activation Energy ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Base Alloy ◽  
True Strain ◽  
Constitutive Behavior ◽  
Compression Tests ◽  
Primary Si ◽  
Constitutive Parameters

Abstract Aluminum piston alloys of the AA4032 type are produced by direct-chill (DC) casting and subsequent forging; therefore, it is important to understand their thermomechanical behavior. In recent years, it was shown that additions of Cu and Er could improve mechanical properties of these alloys at room and high temperatures. In this work, we studied the constitutive behavior of AA4032-type alloys with and without Cu and Er additions. The experimental true stress–true strain curves were obtained by compression tests under various temperatures [683 K to 723 K (410 °C to 450 °C)] and strain rates (0.01 to 10 s−1) to determine constitutive parameters [strain-rate sensitivity, activation energy, and Zener–Hollomon (Z) parameter] for the hot deformation behavior of AA4032-type piston alloys with and without additions of Cu and Er. The flow stress decreased with increasing deformation temperature and decreasing strain rate. The results also showed that increasing the Cu content increased the flow stress over the applied range of deformation conditions due to solid-solution strengthening and the formation of primary Si particles, which led to an increase in the activation energy during hot deformation. Moreover, the main microstructural damage in the AA4032 alloy with 3.5 pct Cu was predominantly due to the cracking of primary Si particles. Additions of 0.4 pct Er and 3.5 pct Cu lower the activation energy of deformation, Q, as compared to the base alloy and the alloy with 3.5 pct Cu. The microstructures in the deformed specimens consisted of subgrains, recrystallized grains, and fine eutectic phases. The alloys containing Er demonstrated more polygonized grains at a low strain rate than the alloys without Er, indicating that Er hindered recrystallization development. The peak stress of the AA4032 alloy with 3.5 pct Cu alloy was higher than for the base AA4032 alloy and for the AA4032 alloy with 3.5 pct Cu and 0.4 pct Er additions, which was attributed to the prevalence of the work-hardening mechanism over the softening mechanism.

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.

Tension Tests at Constant True Strain Rates

1945 ◽  
Vol 12 (4) ◽  
pp. A217-A227
Author(s):  
C. W. MacGregor ◽  
J. C. Fisher
Keyword(s):  
Strain Rate ◽  
True Strain ◽  
Testing Temperature ◽  
True Stress ◽  
Strain Rates ◽  
Stress Strain ◽  
True Strain Rate ◽  
Influence Of Temperature ◽  
Tension Tests ◽  
Strain Type

Abstract Tension tests of the true stress-strain type are reported for which the true strain rate is maintained constant throughout each test. Several metals are investigated under testing temperatures ranging from −183 C to 665 C. The influence of temperature and strain velocity on the true stress-strain properties is described. A single variable called the velocity-modified temperature is used to represent the combined influences of true strain rate and testing temperature.

scholarly journals Uniaxial tension test on Rubber at constant true strain rate

2012 ◽  
Vol 26 ◽  
pp. 01011
Author(s):  
J.-C. Petiteau ◽  
R. Othman ◽  
E. Verron ◽  
H.L. Sourne ◽  
J.-F. Sigrist ◽  
...  
Keyword(s):  
Strain Rate ◽  
Uniaxial Tension ◽  
True Strain ◽  
Tension Test ◽  
True Strain Rate ◽  
Uniaxial Tension Test ◽  
Constant True Strain Rate

scholarly journals Dynamic uniaxial extension of elastomers at constant true strain rate

2013 ◽  
Vol 32 (2) ◽  
pp. 394-401 ◽  
Author(s):  
Jean-Christophe Petiteau ◽  
Ramzi Othman ◽  
Pierrick Guégan ◽  
Hervé Le Sourne ◽  
Erwan Verron
Keyword(s):  
Strain Rate ◽  
True Strain ◽  
Uniaxial Extension ◽  
True Strain Rate ◽  
Constant True Strain Rate
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