Mechanical Properties of E21 (Mn, Fe)3AIC-Base Alloys

1998 ◽  
Vol 552 ◽  
Author(s):  
Kensyo Suzuki ◽  
Hideki Hosoda ◽  
Shuji Hanada
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Temperature Dependence ◽  
Volume Fraction ◽  
Primary Phase ◽  
Positive Temperature ◽  
Compression Tests ◽  
Positive Temperature Dependence ◽  
Fe Content ◽  
Work Hardening Coefficient

ABSTRACTMechanical properties of E21 (Mn, Fe)3AlC-base alloys were investigated. The E21 crystal structure is closely related to L12, and thereby E21 compounds are expected to exhibit superior properties similar to those of the L12 Ni3AL. Nominal compositions are fixed to be 60mol%(Mn, Fe)-20mol%A1–20mol%C. Alloys were prepared by mechanical alloying and hot pressing. ICP chemical analysis, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis were carried out for alloy characterization. Mechanical properties were evaluated by Vickers hardness tests at room temperature (RT) and compression tests from RT to 1273K. Strain rate dip tests were also carried out. It is found that most alloys are composed of two phases of E21 as the primary phase and graphite as the precipitates, and that the volume fraction of graphite increases with increasing Fe content. Hardness and 0.2% flow stress at RT are raised with increasing Fe content. At RT, 0.2% flow stress and fracture strength of Fe3A1C alloy used are 2.9GPa and 3.4GPa, respectively. An alloy containing 40%Mn-20%Fe shows weak positive temperature dependence of strength at 700–800K, similar to the observation in some Co3AIC alloys. Moreover, work-hardening coefficient of all alloys shows strong positive temperature dependence below 700K. These results suggest the occurrence of K-W related mechanism for plastic deformation in these alloys.

Planar Defects and their Role in Physics-Mechanical Properties of Ordered Alloys and Intermetallides

2007 ◽  
Vol 567-568 ◽  
pp. 117-121
Author(s):  
Mikhail D. Starostenkov ◽  
Evgenia Dudnik ◽  
Galina Popova ◽  
Evgeniya Chernykh
Keyword(s):  
Mechanical Properties ◽  
Temperature Dependence ◽  
Unique Property ◽  
Positive Temperature ◽  
Planar Defects ◽  
Positive Temperature Dependence ◽  
Ordered Alloys ◽  
Local Properties ◽  
Order Structures

Ordered alloys and intermetallides are important constructional materials, because they have a unique property – positive temperature dependence of yield stress. It is known that antiphase boundaries and washing effects of order, structures and concentrations of components near the boundaries are of great impotence in the appearance of positive temperature dependence. But superstructures have not only APB but also APB tubes, APB stripes. Their role is also important in physical and physics-mechanical properties of ordered alloys and intermetallides. The paper presents the classification of all the types of planar defects and their local properties for some alloys of different superstructure types.

Effect of Strain Rate on the Plastic Behaviour of Ll2 Compounds Based on Ni3Al

1988 ◽  
Vol 133 ◽  
Author(s):  
Seiji Miura ◽  
Shouichi Ochiai ◽  
Yoshihiro Oya ◽  
Yoshinao Mishima ◽  
Tomoo Suzuki
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Rate Sensitivity ◽  
Grain Boundary Sliding ◽  
Rate Dependence ◽  
Strain Rate Dependence ◽  
Positive Temperature ◽  
Fine Grain ◽  
Positive Temperature Dependence

ABSTRACTIn both single and polycrystalline Ni3Al, no strain rate dependence of 0.2% flow stress is observed in a temperature range where anomalous positive temperature dependence of strength is exhibited. A distinct strain rate dependence is observed, however, in single crystals when the test temperature is raised beyond the peak in flow stress. It is shown that (111) type slip involving diffusional process is responsible for the strain rate sensitivity at near [001] orientation, while (001) type slip which is governed by the Peierls mechanism at orientations away from [001]. In polycrystalline compound with a fine grain size an apparent loss of the positive temperature dependence of strength is observed at a slower strain rate due to grain boundary sliding.

The Temperature Dependence of the Mechanical Properties of Gamma TiAl

1994 ◽  
Vol 364 ◽  
Author(s):  
B. Viguier ◽  
J. Bonneville ◽  
K. J. Hemker ◽  
J. L. Martin
Keyword(s):  
Mechanical Properties ◽  
Flow Stress ◽  
Strain Rate ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Strain Rate Sensitivity ◽  
Rate Sensitivity ◽  
Dislocation Motion ◽  
Compression Tests ◽  
Wide Range

AbstractMechanical properties of a polycrystalline single phased γ Ti47Al51Mn2 alloy were studied by compression tests in a wide range of temperature (100 K - 1300 K). We report, in this paper, the temperature dependence of both the flow stress and its strain rate sensitivity. These dependencies show the existence of three temperature domains corresponding to different dislocation motion mechanisms. The temperature dependence of the flow stress strain rate sensitivity is compared with values measured in single crystals1.

Constitutive Modeling for Flow Stress Behavior of Nimonic 80A Superalloy During Hot Deformation Process

2016 ◽  
Vol 35 (3) ◽  
pp. 327-336 ◽  
Author(s):  
Sendong Gu ◽  
Liwen Zhang ◽  
Chi Zhang ◽  
Wenfei Shen
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
Hot Deformation ◽  
Critical Strain ◽  
Volume Fraction ◽  
Constitutive Models ◽  
Avrami Equation ◽  
Peak Strain ◽  
Compression Tests ◽  
Nimonic 80A

AbstractThe hot deformation characteristics of nickel-based alloy Nimonic 80A were investigated by isothermal compression tests conducted in the temperature range of 1,000–1,200°C and the strain rate range of 0.01—5 s–1on a Gleeble-1500 thermomechanical simulator. In order to establish the constitutive models for dynamic recrystallization (DRX) behavior and flow stress of Nimonic 80A, the material constantsα,nand DRX activation energyQin the constitutive models were calculated by the regression analysis of the experimental data. The dependences of initial stress, saturation stress, steady-state stress, dynamic recovery (DRV) parameter, peak strain, critical strain and DRX grain size on deformation parameters were obtained. Then, the Avrami equation including the critical strain for DRX and the peak strain as a function of strain was established to describe the DRX volume fraction. Finally, the constitutive model for flow stress of Nimonic 80A was developed in DRV region and DRX region, respectively. The flow stress values predicted by the constitutive model are in good agreement with the experimental ones, which indicates that the constitutive model can give an accurate estimate for the flow stress of Nimonic 80A under the deformation conditions.

Positive temperature dependence of time-dependent breakdown of GaN-on-Si E-mode HEMTs under positive gate stress

2019 ◽  
Vol 115 (5) ◽  
pp. 052103 ◽  
Author(s):  
F. Masin ◽  
M. Meneghini ◽  
E. Canato ◽  
C. De Santi ◽  
A. Stockman ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Time Dependent ◽  
Positive Temperature ◽  
Positive Temperature Dependence ◽  
Gan On Si

Hot Deformation Behavior and Microstructure of U720Li Alloy

2013 ◽  
Vol 709 ◽  
pp. 143-147 ◽  
Author(s):  
Tao Wang ◽  
Zhao Li ◽  
Shu Hong Fu ◽  
Yong Zhang ◽  
Yu Xin Zhao ◽  
...  
Keyword(s):  
Grain Size ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Primary Phase ◽  
Compression Tests ◽  
Hot Deformation Behavior ◽  
Fine Grain ◽  
Lower Strain

The hot deformation behavior of U720Li was investigated by isothermal compression tests at temperature ranging from 1060-1180°C and strain rate from 0.001s-1 to 20s-1. The flow stress-strain curves and microstructures were investigated and a constitutive equation was established. It is found that flow stress is sensitive to stain rate and deformation temperature greatly. The higher stain rate resultes in a larger fluctuation in flow stress. The hot deformation activation energy is determined to be 552.8kJ/mol. Grain size increases with increasing temperature and decreases firstly and then increases with increasing strain rate. U720Li alloy should be deformed below the solve temperature of γ primary phase with lower strain rate in order to obtain the even and fine grain size.

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