Deformation Behaviour of an AX41 Magnesium Alloy at Elevated Temperatures

2007 ◽  
Vol 567-568 ◽  
pp. 321-324
Author(s):  
Zuzanka Trojanová ◽  
Pavel Lukáč ◽  
Zoltán Száraz
Keyword(s):  
Magnesium Alloy ◽  
Stress Relaxation ◽  
Strain Rate ◽  
Uniaxial Tension ◽  
Elevated Temperatures ◽  
Deformation Behaviour ◽  
Initial Strain Rate ◽  
Testing Temperature ◽  
Tension Tests ◽  
Deformation Processes

The deformation behaviour of the ternary magnesium alloy AX41 (4%Al-1%Ca-balance Mg) were investigated in uniaxial tension tests at temperatures between 20 and 300 °C and at an initial strain rate ranging in the order 10-4 s-1. The yield stress of the alloy is very sensitive to the testing temperature. Stress relaxation tests were performed with the aim to reveal physical base of deformation processes.

Deformation Behavior And Internal Stress Of Icosahedral Al-Pd-Mn With Decagonal Phase Lamellae At Elevated Temperatures

1998 ◽  
Vol 553 ◽  
Author(s):  
H. Hirai ◽  
T. Tomita ◽  
F. Yoshida ◽  
H. Nakashima
Keyword(s):  
Stress Relaxation ◽  
Strain Rate ◽  
Internal Stress ◽  
Stress Exponent ◽  
Deformation Behavior ◽  
Elevated Temperatures ◽  
Initial Strain Rate ◽  
Decagonal Phase ◽  
Thermally Activated ◽  
High Internal Stress

AbstractFine decagonal phase lamellae-bearing icosahedral Al-Pd-Mn quasicrystals were tested compressionally at temperatures of 997 to 1073 K and initial strain rate of 3 × 10−5. to I × 10−4 S−1, and stress relaxation tests were performed at various stages of deformation. The results confirmed the thermally activated nature of deformation, and the stress exponent of strain rate was around 4. Internal stress for deformation estimated by Kikuchi's method reached 50 to 90 % of applied stress. The effective stress exponent of strain rate was revealed to be about 1.3. At least a part of high internal stress was attributable to complicated dislocation microstructure.

scholarly journals ANALYSIS OF DEFORMATION PROCESSES OF MAGNESIUM ALLOY AT ELEVATED TEMPERATURES BY ORIENTATION MAPPING

2011 ◽  
Vol 23 (1) ◽  
pp. 53 ◽  
Author(s):  
Ping Yang ◽  
Li Meng ◽  
Yisong Hu ◽  
Zude Zhao ◽  
Xueping Ren
Keyword(s):  
Magnesium Alloy ◽  
Elevated Temperatures ◽  
Plastic Slip ◽  
Rotation Axes ◽  
Orientation Mapping ◽  
Back Scattering ◽  
Deformation Processes ◽  
Relationship Of ◽  
The Relationship

Orientation mapping based on electron back scattering diffraction technique was applied to reveal the distributions of disorientations and rotation axes of grains caused by plastic slip and twinning during channel die compression in magnesium alloy ZA31. In addition, the orientations of dynamically recrystallized grains and deformed grains were separated and compared with respect to their initial textures. The relationship of strain and {1012} twin amount was determined quantitatively by referring to twin orientations. The reasons leading to the observed phenomena are analyzed and discussed.

On Phenomenon of Superplasticity in Fe3AL with Large Grains

1994 ◽  
Vol 364 ◽  
Author(s):  
Aidang Shan ◽  
Dongliang Lin
Keyword(s):  
Tensile Test ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
Initial Strain Rate ◽  
Optical Microscope ◽  
Al Alloys ◽  
Initial Strain ◽  
Atomic Percent ◽  
Maximum Elongation ◽  
Grain Sizes

AbstractA variety of Fe3Al alloys including Fe-25Al, Fe-28Al, Fe-28Al-4Cr and Fe-28Al-2Ti (all in atomic percent) have been investigated by tensile test to find if these alloys could have superplasticity at elevated temperatures, the results revealed that all these alloys exhibited large elongations when the temperature is higher than 600°C. At 850°C , under appropriate initial strain rate, the elongation is all above 300%. For Fe-28Al-2Ti, the maximum elongation reached 585%. Maximum m values are all above 0.3. Initial grain sizes are bigger than 100μm but became finer after deformation. Fracture happened with necking but no cavities were found under optical microscope. Characteristics of this phenomenon were summarized and discussed.

Thermally Activated Dislocation Motion in an AS21 Alloy and Alloy Reinforced with Short Ceramic Fibres Studied at Elevated Temperatures

2013 ◽  
Vol 592-593 ◽  
pp. 71-74
Author(s):  
Zuzana Zdražilová ◽  
Zuzanka Trojanová ◽  
Kristián Máthis ◽  
Pavel Lukáč
Keyword(s):  
Magnesium Alloy ◽  
Stress Relaxation ◽  
Applied Stress ◽  
Elevated Temperatures ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Dislocation Motion ◽  
Thermally Activated ◽  
Effective Components ◽  
Thermally Activated Process

AS21 magnesium alloy (2.1Al-1Si-balance Mg in wt.%) and the alloy reinforced with short δ-Al2O3fibres (Saffil®) were deformed in compression at temperatures between 23 and 300 °C. Stress relaxation tests were performed in order to reveal features of the thermally activated dislocation motion. Internal and effective components of the applied stress have been estimated. The activation volume decreases with increasing effective stress. The values of the activation volume and the activation enthalpy indicate that the main thermally activated process in the alloy as well as in the composite is the dislocation motion in non-compact planes.

Deformation Behavior of ZK60 Magnesium Alloy at Elevated Temperature

2014 ◽  
Vol 788 ◽  
pp. 93-97 ◽  
Author(s):  
Chun Yan Wang ◽  
Hai Qun Qi ◽  
Kun Wu ◽  
Ming Yi Zheng
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Deformation Behavior ◽  
Squeeze Casting ◽  
Testing Temperature ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Temperature Range ◽  
Zk60 Magnesium Alloy

The high temperature compressive tests of squeeze casting ZK60 magnesium alloy in the testing temperature range of 523-723K and strain rate range of 0.001-10s-1 were performed on Gleeble-1500D thermal simulator testing machine. Optical microscopy was performed to elaborate on the dynamic recrystallization (DRX) grain growth. TEM observation indicated that the mechanical twinning, dislocation slip, and dynamic recrystallization are the materials typical deformation features. Variations of flow behavior with deformation temperature as well as strain rate were analyzed. Analysis of the flowing deformation behavior and microstructure observations indicated that the flow localization was observed at lower testing temperature and higher strain rates. Dynamic recrystallization occurred at higher testing temperature and moderate strain rates, which improved the ductility of the material. The results indicated that at the testing temperatures lower than 573K and strain rates higher than 1s-1, the material exhibited flow instability manifesting as bands of flow localizations. These temperatures and strain rates should be avoided in processing the material. Dynamic recrystallization occurs in the temperature range 573-723K and the strain rate range 0.001-0.1s-1. The number of dynamic recrystallization grains is less at lower temperature and higher strain rate than higher temperature and lower strain rate. The dynamic recrystallization is inadequate at 573-623K while the dynamic recrystallization grain growth has been observed in the temperature range of 673-723K. Therefore it may be considered that the optimum processing parameters for hot working of squeeze casting ZK60 magnesium alloy are 648K and 0.001-0.01s-1, at which fine dynamic recrystallization microstructure can be obtained.

Stress Relaxation in an AZ31 Magnesium Alloy

2011 ◽  
Vol 465 ◽  
pp. 101-104 ◽  
Author(s):  
Pavel Lukáč ◽  
Zuzanka Trojanová
Keyword(s):  
Magnesium Alloy ◽  
Stress Relaxation ◽  
Deformation Temperature ◽  
Room Temperature ◽  
Activation Volume ◽  
Initial Strain Rate ◽  
Az31 Magnesium Alloy ◽  
Thermally Activated ◽  
Relaxation Curves ◽  
Thermally Activated Process

Stress relaxation tests have been used in order to determine parameters of a possible thermally activated process in AZ31 magnesium alloy. The samples were deformed at a constant initial strain rate of 6.7x10-5 s-1 at various temperatures between room temperature and 300 °C. Stress relaxation, i.e. a decrease in the stress with time, was measured at various stress levels and at various temperatures. An analysis of the stress relaxation curves enabled to estimate the internal stress as a function of the strain and the test temperature. It has been shown that the activation volume is a function of the effective stress independently of the deformation temperature.

Deformation and Fracture of a Magnesium Alloy at Elevated Temperatures

2013 ◽  
Vol 592-593 ◽  
pp. 75-78
Author(s):  
Pavel Lukáč ◽  
Tibor Donič ◽  
Mária Chalupová ◽  
Peter Palček ◽  
Zuzanka Trojanová ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Initial Strain Rate ◽  
Rapid Decrease ◽  
Tensile Yield Strength ◽  
Fracture Mechanisms ◽  
Deformation And Fracture ◽  
Deformation Tests ◽  
Scanning Electron

Magnesium alloy EZ10 was deformed in tension at temperatures from room temperature up to 400 °C with an initial strain rate of 2.7x10-3s-1. Deformation tests showed a rapid decrease of the tensile yield strength at temperatures higher than 300 °C. Microstructure of the deformed samples was analysed with light microscope. Fracture mechanisms were estimated using scanning electron microscopy.

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