Beta-Forging of Titanium Ti6Al4V Alloy Powders: Phase Evolution Modeling and Strain-Rate Relation

2014 ◽  
Vol 622-623 ◽  
pp. 15-26
Author(s):  
Claudio Testani ◽  
Antonino Squillace ◽  
Antonello Astarita
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Rate Sensitivity ◽  
Phase Evolution ◽  
High Temperature Deformation ◽  
Fatigue Properties ◽  
Temperature Deformation ◽  
Compression Tests ◽  
Process Modification ◽  
Deformation Tests

Ti6Al4V is one of the best known and studied titanium alloy for the optimization of the thermo-mechanical treatments. The Ti-forgings represent a valid opportunity for the aircraft manufacturers and designers because of high tensile and fatigue properties. Nevertheless the total-cost reduction of the manufacturing-chain requires both: the ability to manufacture nearer-shaped components by mean of forging-process-modification and less final machining (material scraps). Even if Ti6Al4V is a well known alloy, any process parameters modification introduced still represents a challenge for the metallurgists and manufacturers.The idea, at the base of the present work, has been the feasibility study of forging experiments in the Beta-field using Hot Isostatic Pressed (HIP) powders billets. The preliminary compression tests has been carried out in laboratory and the results have been validated in a industrial Forging-Workshop. The deformation behavior of Ti6Al4V HIPped powders during high temperature deformation tests is reported. Laboratory compression and tensile tests have been coupled with relaxation tests in order to achieve robust data about strain rate sensitivitym-coefficient and activation energy Q.The obtained results have been fitted for the assessment of generalized exponential deformation law. The final result is a “Dorn model” that takes into account and compares all the results from the three different deformation tests: compression, tensile and relaxation. The deformation tests have been carried out at temperatures ranging from 1173 K up to 1373 K and strain rate from 0,01 s-1up to about 1 s-1, trying to describe the high temperature complex shape forging operations.Finally the recorded deformation curves has been used for modeling by means of FEM DeformTM code the deformation process and microstructure evolution by means of an Avrami type law.

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 plasticity of cubic bismuth oxide

1996 ◽  
Vol 11 (6) ◽  
pp. 1433-1439 ◽  
Author(s):  
Anne Vilette ◽  
S. L. Kampe
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Bismuth Oxide ◽  
Rate Sensitivity ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Cubic Phase ◽  
Superplastic Behavior ◽  
Wide Range

Cubic (δ) bismuth oxide (Bi2O3) has been subjected to high temperature deformation over a wide range of temperatures and strain rates. Results indicate that bismuth oxide is essentially incapable of plastic deformation at temperatures below the monoclithic to cubic phase transformation which occurs at approximately 730 °C. Above the transformation temperature, however, Bi2O3 is extensively deformable. The variability of flow stress to temperature and strain rate has been quantified through the determination of phenomenological-based constitutive equations to describe its behavior at these high temperatures. Analysis of the so-determined deformation constants indicate an extremely strong sensitivity to strain rate and temperature, with values of the strain-rate sensitivity approaching values commonly cited as indicative of superplastic behavior.

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 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.

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.

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.

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