High Temperature Deformation of Wrought Zn-Containing Magnesium Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1482-1487 ◽  
Author(s):  
S. Spigarelli ◽  
Mohamad El Mehtedi ◽  
D. Ciccarelli ◽  
Menachem Bamberger ◽  
Giuseppe Cupitò ◽  
...  
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Flow Stress ◽  
Magnesium Alloys ◽  
Temperature Response ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Lower Strength ◽  
The Difference ◽  
Zn Alloys

The high temperature response in torsion and creep of two extruded Mg-Zn alloys was investigated in the present study. The alloy 0 (Mg-2Zn-1Mn) was found to exhibit a lower strength than the alloy 2 (Mg-0.55Zn-0.79Mn-0.75Al-0.17Ca), even if the activation energy for creep was similar for both materials (170-180 kJ/mol). The difference in flow stress was here preliminarily attributed to the precipitation of fine Al2Ca particles.

High-Temperature Deformation of Yba2Cu307-8 With Ag Additions

1989 ◽  
Vol 169 ◽  
Author(s):  
J.L. Routbort ◽  
K.C. Goretta ◽  
J.P. Singh
Keyword(s):  
Activation Energy ◽  
Steady State ◽  
High Temperature ◽  
Flow Stress ◽  
Compressive Strain ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Strain Rates ◽  
Steady State Flow ◽  
Ag Additions

AbstractThe steady‐state flow stress of YBa2Cu3O7‐δ containing 15 to 30 vol.% Ag has been measured in air at nearly constant compressive strain rates between 5 x 10‐6 and 1 x 10‐4 s‐1 from 830 to 900°C. Addition of Ag dramatically decreases the flow stress compared to that of the pure superconductor, but the stress exponents and the activation energy for deformation remain unchanged.

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.

Constitutive Analysis of the High-Temperature Deformation Behavior of Single Phase α-Ti and α+β Ti-6Al-4V Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3607-3612 ◽  
Author(s):  
Jeoung Han Kim ◽  
Jong Taek Yeom ◽  
Nho Kwang Park ◽  
Chong Soo Lee
Keyword(s):  
High Temperature ◽  
Flow Stress ◽  
Deformation Behavior ◽  
Single Phase ◽  
Volume Fraction ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Β Phase ◽  
Α Phase ◽  
Self Consistent

The high-temperature deformation behavior of the single-phase α (Ti-7.0Al-1.5V) and α + β (Ti-6Al-4V) alloy were determined and compared within the framework of self-consistent scheme at various temperature ranges. For this purpose, isothermal hot compression tests were conducted at temperatures between 650°C ~ 950°C to determine the effect of α/β phase volume fraction on average flow stress under hot-working condition. The flow behavior of α phase was estimated from the compression test results of single-phase α alloy whose chemical composition is close to that of α phase of Ti-6Al-4V alloy. On the other hand, the flow stress of β phase in Ti-6Al-4V was predicted by using self-consistent method. The flow stress of α phase was higher than that of β phase above 750°C, while the β phase revealed higher flow stress than α phase at 650°C. Also, at temperature above 750°C, the predicted strain rate of β phase was higher than that of α phase. It was found that the relative strength between α and β phase significantly varied with temperature.

Hot Working of the ZEK200 Magnesium Alloy

2008 ◽  
Vol 604-605 ◽  
pp. 212-222 ◽  
Author(s):  
S. Spigarelli ◽  
Mohamad El Mehtedi ◽  
P. Ricci
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Direct Chill ◽  
Equivalent Strain ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Torsion Testing ◽  
A Value ◽  
Complete Recrystallization

The high temperature workability of the ZEK200 Mg-alloy produced by Direct Chill casting (DC) was investigated by torsion testing between 200 and 450°C. The alloy exhibited a higher strength and a slightly lower equivalent strain to fracture than AZ31 and ZM21 produced by DC. The calculation of the constitutive equation gave a value of the activation energy for high temperature deformation close to 175 kJ/mol, in line with those calculated by following the same procedure in AZ31 and ZM21. Partial or complete recrystallization of the deformed structure was observed at 350 and 400°C respectively. Grain growth occurred after recrystallization in the samples tested at 450°C.

Modelling Dynamic Recovery and Recrystallization of Metals by a New Non-Equilibrium Thermodynamics Approach

2007 ◽  
Vol 558-559 ◽  
pp. 517-522
Author(s):  
Ming Xin Huang ◽  
Pedro E.J. Rivera-Díaz-del-Castillo ◽  
Sybrand van der Zwaag
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Flow Stress ◽  
Dislocation Density ◽  
Dynamic Recovery ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Equilibrium Thermodynamics ◽  
Burgers Vector ◽  
Non Equilibrium

A non-equilibrium thermodynamics-based approach is proposed to predict the dislocation density and flow stress at the steady state of high temperature deformation. For a material undergoing dynamic recovery and recrystallization, it is found that the total dislocation density can be expressed as ( )2 ρ = λε& b , where ε& is the strain rate, b is the magnitude of the Burgers vector and λ is a dynamic recovery and recrystallization related parameter.

scholarly journals Effect of Annealing on Structure and Mechanical Behavior of an AA2139 Alloy

2014 ◽  
Vol 783-786 ◽  
pp. 258-263 ◽  
Author(s):  
Damir Tagirov ◽  
Daria Zhemchuzhnikova ◽  
Marat Gazizov ◽  
Rustam Kaibyshev
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Flow Stress ◽  
Room Temperature ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Aged Alloy ◽  
Coarse Particles ◽  
Initial Material ◽  
High Ductility

An AA2139 alloy with a chemical composition of Al–4.35Cu-0.46%Mg–0.63Ag-0.36Mn–0.12Ti (in wt.%) and an initial grain size of about 155 μm was subjected to annealing at 430°C for 3 h followed by furnace cooling. This treatment resulted in the formation of a dispersion of coarse particles having essentially plate-like shape. The over-aged alloy exhibits lower flow stress and high ductility in comparison with initial material in the temperature interval 20-450°C. Examination of microstructural evolution during high-temperature deformation showed localization of plastic flow in vicinity of coarse particles. Over-aging leads to transition from ductile-brittle fracture to ductile and very homogeneous ductile fracture at room temperature.

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