Influence of Annealing Temperature on Microstructure and Properties of Warm-Rolled AZ31 Magnesium Alloy Sheets

2013 ◽  
Vol 747-748 ◽  
pp. 352-358
Author(s):  
Hua Zhang ◽  
Guang Sheng Huang ◽  
Jin Han Lin ◽  
Li Fei Wang
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Annealing Temperature ◽  
Az31 Alloy ◽  
Az31 Magnesium Alloy ◽  
Strain Hardening Exponent ◽  
N Value ◽  
Microstructure And Properties ◽  
Different Temperatures ◽  
R Value

Warm-rolled AZ31 alloy sheets were annealed at different temperatures ranging from 150 to 450°C. Effects of annealing temperature on microstructure and properties of warm-rolled AZ31 alloy sheets, especially the formability, were investigated. The results revealed that the Lankford value (r-value) and strain-hardening exponent (n-value) first increased and then became relatively steady with the increase of annealing temperature. The Erichsen value (IE) first increased and then decreased with the increase of annealing temperature and the AZ31 alloy sheets exhibited the highest IE of 3.02 mm when annealing at 250°C, which can be mainly attributed to a larger elongation, a lower r-value and a higher n-value.

Study on Compression Behaviour of AZ31 Magnesium Alloy at Room-Temperature

2012 ◽  
Vol 476-478 ◽  
pp. 1960-1964
Author(s):  
Jia Le Sun ◽  
Rui Chun Li ◽  
Gao Feng Quan ◽  
Zhao Ming Liu
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Az31 Alloy ◽  
Strain Hardening Exponent ◽  
Surface Cracks ◽  
Compression Properties ◽  
Compression Behaviour ◽  
Az31 Mg Alloy

The microstructure, surface morphology, compression properties, deformation behaviour and strain hardening exponent of as-cast and as-extruded AZ31 Mg alloy after different annealing treatments were investigated. The results show that the compression properties are great different between cast AZ31 alloy and extruded AZ31 alloy. Extruded AZ31 alloy is discontinuous yield and on the surface no signs of damage have been observed; on the contrast, cast AZ31 alloy is continuous yield and shows wavy patterns, and the surface cracks can be easily found. In addition, there is a linear relationship between the strain hardening exponent in first deformation stage and the yield ratio. Further more, the twinning mechanism plays very different role in cast AZ31 alloy and extruded AZ31 alloy.

Determination of Optimal Coiling Temperature and Cold Reduction Ratio of 260MPa Grade High Strength Nb-IF Steel

2011 ◽  
Vol 399-401 ◽  
pp. 148-151
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Li Xiao
Keyword(s):  
High Strength ◽  
Strain Ratio ◽  
Reduction Ratio ◽  
Cold Reduction ◽  
Strain Hardening Exponent ◽  
If Steel ◽  
Coiling Temperature ◽  
Plastic Strain Ratio ◽  
N Value ◽  
R Value

Hot rolled 260MPa grade high strength Nb-IF steel sheet was used to study the effect of coiling temperature and cold reduction ratio on the microstructures and mechanical properties. The experimental results showed that the recrystallization has finished. Under 650°Ccoiling temperature and 75% cold reduction ratio, and under 600°C or 700°C coiling temperature and 65% cold reduction ratio, the plastic strain ratio r value and the strain hardening exponent n value were reached the maximum, and respectively, the r value was approximate 1.8, the n value was approximate 0.26. That obtains optimally match of high strength and punching property.

ACCUMULATIVE ROLL BONDING OF AZ31 MAGNESIUM ALLOY

2008 ◽  
Vol 22 (18n19) ◽  
pp. 2833-2939 ◽  
Author(s):  
S. M. FATEMI-VARZANEH ◽  
A. ZAREI-HANZAKI ◽  
M. HAGHSHENAS
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Accumulative Roll Bonding ◽  
Az31 Alloy ◽  
Thickness Reduction ◽  
Az31 Magnesium Alloy ◽  
Total Strain ◽  
Roll Bonding ◽  
Fine Grain

This work conducted to investigate the effects of accumulative roll bonding (ARB) method on achieving the ultra-fine grain microstructure in AZ31 alloy. Accordingly, a number of ARB routes at 400°C, applying thickness reductions per pass of 35%, 55%, and 85% were performed. The results indicate that both the final grain size and the degree of bonding have been dictated by the thickness reduction per pass. The larger pass reductions promote a higher degree of bonding. Increasing the total strain stimulates the formation of a more homogeneous ultra fine grain microstructure.

scholarly journals Study of ph effect on AZ31 magnesium alloy corrosion for using in temporary implants

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Caio A. J. da Silva Da Silva ◽  
Lilian N. M. Braguin ◽  
Larissa O. Berbel ◽  
Bárbara V. G. De Viveiros ◽  
Jesualdo L. Rossi ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Body Fluid ◽  
Ph Effect ◽  
Az31 Alloy ◽  
Corrosion Process ◽  
Az31 Magnesium Alloy ◽  
Nacl Solution ◽  
Agar Gel ◽  
Ph Variation ◽  
Elemental Chemical Analysis

Currently, magnesium alloys are gaining great interest for medical applications due to their degrading properties in the human body ensuring a great biocompatibility. These alloys also provide profitable mechanical properties due similarities with human bone.  However, a difficulty in applying these materials in the biomaterials industries is the corrosion prior to cell healing. The effect of the chemical composition of Mg alloys on their corrosion behavior is well known. In this study, samples of AZ31 magnesium alloy were cut into chips for elemental chemical analysis by neutron activation analysis (NAA). Concentrations of the elements As, La, Mg, Mn, Na, Sb and Zn were determined in the AZ31 alloy. Visualization tests of agar corrosion development in various media, of 0.90% sodium chloride solution (mass), phosphate buffer saline (PBS) and simulated body fluid (SBF) were performed. Visualizations of the effect of agar gel corrosion revealed pH variation during the corrosion process due to the released into the cathode. The highest released of hydroxyl ions occurred in NaCl solution compared to PBS and SBF solutions indicating that NaCl solution was much more aggressive to the alloy compared to the others.

scholarly journals INFLUENCE OF A PREFABRICATED-CROWN ROLLING PROCESS ON THE CORROSION BEHAVIOUR OF AZ31 MAGNESIUM ALLOY

2021 ◽  
Vol 55 (4) ◽  
Author(s):  
Zhiquan Huang ◽  
Jinchao Zou ◽  
Junpeng Wang ◽  
Yanjie Pei ◽  
Renyao Huang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Plate Thickness ◽  
Az31 Alloy ◽  
Rolling Process ◽  
Charge Transfer Resistance ◽  
Az31 Magnesium Alloy ◽  
Transfer Resistance

The present study aims to investigate the effect of a prefabricated-crown rolling process on the corrosion characteristic of the AZ31 magnesium alloy. Specimens made of the AZ31 alloy were rolled under various crown conditions, and their microstructure evolution and corrosion behavior were analyzed. The corrosion behavior was studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed that the corrosion-current density of the AZ31 alloy with a side pressure of 37.5 % of the plate thickness of the precast convexity decreased from 3.79 × 10–6 A/cm2 to 1.80 × 10–6 A/cm2, and the difference between the edge and the middle of the AZ31 alloy was shortened from 2.05 × 10–6 A/cm2 to 1.14 × 10–6 A/cm2. The charge-transfer resistance also increased from 507.1 Ω·cm2 to 581.2 Ω·cm2. The improvement in the corrosion resistance is a result of the more stable corrosion products and microstructure refinement formed after the prefabricated-crown rolling process.

Enhanced Formability of AZ31 Magnesium Alloy Sheet Processed by Equal Channel Angular Rolling and Annealing Treatment

2007 ◽  
Vol 26-28 ◽  
pp. 91-94
Author(s):  
Zhen Hua Chen ◽  
Yong Qi Cheng ◽  
Wei Jun Xia ◽  
Hong Ge Yan ◽  
Ding Chen
Keyword(s):  
Magnesium Alloy ◽  
Rolling Direction ◽  
Annealing Treatment ◽  
Alloy Sheet ◽  
Az31 Magnesium Alloy ◽  
Strain Hardening Exponent ◽  
Drawing Ratio ◽  
Magnesium Alloy Sheet ◽  
Optical Microstructure ◽  
Az31 Magnesium Alloy Sheet

In order to improve the formability of AZ31 magnesium alloy sheet at room temperature, a new process, so-called equal channel angular rolling (ECAR) and followed by annealing treatment was applied to process the sheet. The optical microstructure of the as-received sheet was similar with that of the ECARed one after annealing treatment, the Erichsen value and limiting drawing ratio of the ECARed sheet was about 6.26mm and 1.6, respectively, which was much larger than that of 4.18mm and 1.2 for the as-received sheet. These can be attributed to the low yield ratio and high strain hardening exponent due to the modified texture induced by the shear deformation during ECAR process, which is favor of the activations of basal slipping and twinning at ambient temperature, especially deforming at the rolling direction.

scholarly journals Effects of Pre-Strain on the Evolution of Microstructure and Strain Hardening of Extruded Az31 Magnesium Alloy

2017 ◽  
Vol 20 (4) ◽  
pp. 1003-1009
Author(s):  
Lifei Wang ◽  
Miao Cao ◽  
Shuming Yang ◽  
Hua Zhang ◽  
Dongya Wang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Strain Hardening ◽  
Az31 Magnesium Alloy ◽  
Evolution Of Microstructure

scholarly journals Determination of the Hot Cracking Tendency of a Twin-Roll Cast AZ31 Magnesium Alloy by Means of Gleeble Tests

2018 ◽  
Vol 918 ◽  
pp. 40-47
Author(s):  
Heike Wemme ◽  
Christina Krbetschek ◽  
Madlen Ullmann ◽  
Anna Freigang ◽  
Stefan Plach ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Az31 Alloy ◽  
Hot Cracking ◽  
Az31 Magnesium Alloy ◽  
Cast Magnesium ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Cracking Tendency

The knowledge about the formation of hot cracking in magnesium alloys, such as in twin-roll cast magnesium sheets and strips, is fundamental for a good quality of the strips during the further processing by rolling or welding and minimize the reject. Hot cracking often occurs in the so-called mushy zone, when solid phases and melt coexist, at temperatures where the material no longer exhibits ductility. For the evaluation of the hot cracking tendency of an alloy, the width of the HTBR (High-temperature brittleness range) can be used. On the basis of a test on a Gleeble HDS-V40, the HTBR was determined for a twin-roll cast AZ31 magnesium alloy. The transition between ductile forming behaviour and complete brittle reaction of the AZ31 alloy is confirmed by the observation of the fracture surfaces (determination of the fracture type) in the scanning electron microscope (SEM) and is located at 555 °C. The HTBR shows a range 35 K.

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