Constitutive Analysis and Microstructure Evolution of the High-Temperature Deformation Behavior of an Advanced Intermetallic Multi-Phase γ-TiAl-Based Alloy

2014 ◽  
Vol 922 ◽  
pp. 807-812 ◽  
Author(s):  
Robert Werner ◽  
Emanuel Schwaighofer ◽  
Martin Schloffer ◽  
Helmut Clemens ◽  
Janny Lindemann ◽  
...  
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Thermomechanical Processing ◽  
True Strain ◽  
Strain Curve ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Nominal Composition ◽  
Compression Tests

In the present study the high-temperature deformation behavior of a caste and subsequently HIPed β-solidifying γ-TiAl-based alloy with a nominal composition of Ti-43.5Al-4Nb-1Mo-0.1B (in at. %), termed TNM alloy, is investigated. At room temperature this alloy consists of ordered γ-TiAl, α2-Ti3Al and βo-TiAl phases. By increasing the temperature, α2and βodisorder to α and β, respectively. In order to get a better understanding of dynamic recovery and recrystallization processes during thermomechanical processing, isothermal compression tests on TNM specimens are carried out on a Gleeble®3500 simulator. These tests are conducted at temperatures ranging from 1100 °C to 1250 °C (in the α/α2+β/βo+γ phase field region) applying strain rates in the range of 0.005 s-1to 0.5 s-1up to a true strain of 0.9. The evolution of microstructure along with the dynamically recrystallized grain size during hot deformation is examined by scanning electron microscopy (SEM). The flow softening behavior after reaching the peak stress in the true stress-true strain curve is attributed to dynamic recrystallization. By using the Zener-Hollomon parameter as a temperature-compensated strain rate the dependence of flow stress on temperature and strain rate is shown to follow a hyperbolic-sine Arrhenius-type relationship.

High-Temperature Deformation Behavior of ELI Grade Ti-6Al-4V Alloy with Martensite Microstructure

2007 ◽  
Vol 551-552 ◽  
pp. 365-372 ◽  
Author(s):  
C.H. Park ◽  
Young Gun Ko ◽  
Chong Soo Lee ◽  
Kyung Tae Park ◽  
Dong Hyuk Shin ◽  
...  
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Flow Instability ◽  
True Strain ◽  
Effective Strain ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Martensite Microstructure

High-temperature deformation behavior and microstructural evolution process of ELI Ti-6Al-4V alloy having martensite microstructure were investigated with the variation of strain, strain rate and temperature. A series of hot compression tests was carried out isothermally for martensite microstructure at the true strain range of 0.6 to 1.4, strain rate range of 10-3 s-1 to 1 s-1 and temperature range of 700 oC to 950 oC. The processing maps for martensite microstructures were constructed on the basis of dynamic materials model (DMM). At the strain rate higher than 10-2 s-1 and the temperature lower than 750 oC regions of flow instability such as adiabatic shear band and micro-cracking were observed. Also, after imposing an effective strain of ≈ 1.4, deformed microstructure showed the significant kinking/bending behavior of lamellae resulting in the dynamic globularization associated with the fragmentation of beta-phase. The effects of strain, strain rate and temperature for dynamic globularization were discussed based on the microstructure and efficiency of power dissipation.

Characterization of High Temperature Deformation Behavior of BFe10-1-2 Cupronickel Alloy Using Orthogonal Analysis

2017 ◽  
Vol 36 (7) ◽  
pp. 701-710
Author(s):  
Jun Cai ◽  
Kuaishe Wang ◽  
Xiaolu Zhang ◽  
Wen Wang
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Constitutive Equation ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Statistical Parameters ◽  
Orthogonal Analysis

AbstractHigh temperature deformation behavior of BFe10-1-2 cupronickel alloy was investigated by means of isothermal compression tests in the temperature range of 1,023~1,273 K and strain rate range of 0.001~10 s–1. Based on orthogonal experiment and variance analysis, the significance of the effects of strain, strain rate and deformation temperature on the flow stress was evaluated. Thereafter, a constitutive equation was developed on the basis of the orthogonal analysis conclusions. Subsequently, standard statistical parameters were introduced to verify the validity of developed constitutive equation. The results indicated that the predicted flow stress values from the constitutive equation could track the experimental data of BFe10-1-2 cupronickel alloy under most deformation conditions.

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.

Hot Deformation Behavior of the 30%Mo/Cu-Al2O3 Composite Prepared by Vacuum Hot-Pressed Sintering

2011 ◽  
Vol 117-119 ◽  
pp. 893-896
Author(s):  
Yong Liu ◽  
Yong Wei Sun ◽  
Bao Hong Tian ◽  
Jiang Feng ◽  
Yi Zhang
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Flow Behavior ◽  
Peak Stress ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Hot Deformation Behavior

Hot deformation behavior of the 30%Mo/Cu-Al2O3 composite was investigated by hot compression tests on Gleeble-1500D thermal simulator in the temperature ranges of 450~750°C and the strain rate ranges of 0.01~5s-1, as the total strain is 0.7. The results show that the peak stress increases with the decreased deformation temperature or the increased strain rate. Based on the true stress-strain curves, the established constitutive equation represents the high-temperature flow behavior of the composite, and the calculated flow stresses are in good agreement with the high- temperature deformation experimental results.

High Temperature Deformation Behavior of 25Cr5MoA Nitriding Steel

2011 ◽  
Vol 399-401 ◽  
pp. 240-244
Author(s):  
Yue Zang ◽  
Shu Xia Li ◽  
Yi Kun Yang ◽  
Xue Ping Ren
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Temperature ◽  
True Strain ◽  
Strain Curve ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Deformation Degree

The high temperature deformation law of nitriding steel 25Cr5MoA over the strain rate range 0.001S-1~20S-1and temperature range 850°C to 1150°C was studied in the thermal simulation testing machine Gleeble-1500. Under a certain strain rate and a certain deformation degree, the flow stress decreased with the increase of deformation temperature. Work hardening of nitriding steel 25Cr5MoA was strong when the true strain was less than 0.2, otherwise the flow stress increased slowly, even dropped. High temperature deformation flow stress of nitriding steel 25Cr5MoA was influenced by the deformation temperature and strain rate. When the strain rate was 0.1S-1, true stress-true strain curve exhibited a dynamic recrystallization model, and with the increase of deformation temperature, peak flow stress shift left. When deformation degree was 0.69, the strain rate was 1S-1, and when deformation temperature was in the region of 850°C~1050°C, true stress-true strain curve exhibited a dynamic recovery model. And when the deformation temperature was in the region of 1100°C~1150°C, it showed a dynamic recrystallization model. Dynamic recrystallization diagrams of nitriding steel 25Cr5MoA were also established.

Modeling the High Temperature Deformation Behaviour of a near Alpha Titanium Alloy with Bi-Modal Microstructure

2012 ◽  
Vol 710 ◽  
pp. 533-538 ◽  
Author(s):  
I. Balasundar ◽  
T. Raghu ◽  
B.P. Kashyap
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Strain Rate ◽  
Thermomechanical Processing ◽  
Deformation Behaviour ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Alpha Titanium ◽  
Temperature Strain

The high temperature deformation behaviour of near alpha titanium alloy IMI834 with a bimodal microstructure has been evaluated by carrying out isothermal compression tests over a range of temperature and strain rate. The optimum thermomechanical processing (TMP) parameters i.e., temperature, strain rate that can be used to produce various aeroengine components were identified using dynamic materials modeling (DMM). Using kinetic analysis, a unified constitutive equation that describes the deformation behavior of the material in the selected temperature - strain rate regime has been established and the deformation mechanisms operating in the material were identified.

High Temperature Deformation Behavior of Ti-7333 Titanium Alloy and its Flow Stress Model

2012 ◽  
Vol 538-541 ◽  
pp. 945-950 ◽  
Author(s):  
Jiang Kun Fan ◽  
Hong Chao Kou ◽  
Min Jie Lai ◽  
Bin Tang ◽  
Hui Chang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
High Temperature ◽  
Flow Stress ◽  
Strain Rate ◽  
Deformation Behavior ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Stress Model ◽  
Compression Tests ◽  
Flow Stress Model

The effects of processing parameters on deformation behavior of a new near β titanium alloy were investigated by using compression tests. The experiments were carried out in the Gleeble-3800 thermal and mechanical simulator in the temperature range of 770-970°C and strain rate range of 10-3-10s-1, and height direction reduction of 70%. The results show that the flow stress of Ti-7333 titanium alloy increases obviously with the strain and reaches a peak, then decreases to a steady value. The steady and peak stress significantly decreases with the increase of deformation temperature and decrease of strain rate. The flow stress model of Ti-7333 titanium alloy during high temperature deformation was established by using the regression method. The average relative difference between the calculated and experimental flow stress is 6.33%. The flow stress model can efficiently predict the deformation behavior of Ti-7333 titanium alloy during high temperature deformation.

High Temperature Deformation Mechanism Maps of NiAl

2004 ◽  
Vol 449-452 ◽  
pp. 57-60
Author(s):  
I.G. Lee ◽  
A.K. Ghosh
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Calculation Method ◽  
Deformation Behavior ◽  
Tensile Tests ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Grain Sizes ◽  
Temperature Strain

In order to analyze high temperature deformation behavior of NiAl alloys, deformation maps were constructed for stoichiometric NiAl materials with grain sizes of 4 and 200 µm. Relevant constitute equations and calculation method will be described in this paper. These maps are particularly useful in identifying the location of testing domains, such as creep and tensile tests, in relation to the stress-temperature-strain rate domains experienced by NiAl.

Texture Formation during High Temperature Deformation of Al-3mass%Mg Solid Solution

2005 ◽  
Vol 495-497 ◽  
pp. 579-584 ◽  
Author(s):  
Kazuto Okayasu ◽  
Hiroshi Fukutomi
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Strain Rate ◽  
Deformation Temperature ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Texture Formation ◽  
Compression Tests ◽  
Temperature Strain

Uniaxial compression tests were conducted on Al-3mass%Mg alloy under various temperatures and strain rates. High temperature yielding was observed at the temperatures higher than 623K. Texture examination elucidated that fiber textures are constructed in all the deformation conditions examined in this study. It was found that the kinds and intensities of texture components varied depending on deformation temperature, strain rate and the amount of strain.

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