Effects of Temperature and Sheet Thickness on Formability of AZ31 Magnesium Alloy

2008 ◽  
Vol 604-605 ◽  
pp. 147-152 ◽  
Author(s):  
P. Ricci ◽  
Mohamad El Mehtedi ◽  
L. Barone ◽  
S. Spigarelli
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Sheet Thickness ◽  
Optical Microscope ◽  
Az31 Magnesium Alloy ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Light Optical Microscope ◽  
Effects Of Temperature

The formability of AZ31 magnesium alloy sheets, with two different thicknesses, has been investigated at room temperature and 250°C by means of Nakazima tests. The different straining conditions have been studied by using sheet blanks with several length to width ratios, and Forming Limit Diagrams were then obtained with and without using lubricant. As expected, an increase in temperature was observed to enhance the formality of the alloy. The formability increases also by increasing the thickness as well as by using Teflon foil as lubricant. The microstructure of the deformed samples was analysed by means of light optical microscope.

1006 Effects of Temperature and Strain-Rate on Non-proportion Forming Limit Diagram for AZ31 Magnesium Alloy Sheets

2009 ◽  
Vol 2009.47 (0) ◽  
pp. 337-338
Author(s):  
Yosuke UEKAWA ◽  
Takashi KATAHIRA ◽  
Akiyoshi ODE ◽  
Testuo NAKA ◽  
Takeshi UEMORI ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Strain Rate ◽  
Forming Limit Diagram ◽  
Az31 Magnesium Alloy ◽  
Forming Limit ◽  
Effects Of Temperature

Formability and Microstructure of AZ31 Magnesium Alloy Sheets

2007 ◽  
Vol 344 ◽  
pp. 31-38 ◽  
Author(s):  
Archimede Forcellese ◽  
Mohamad El Mehtedi ◽  
M. Simoncini ◽  
S. Spigarelli
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Microstructural Evolution ◽  
Az31 Magnesium Alloy ◽  
Forming Limit ◽  
Forming Limit Diagrams ◽  
Remarkable Increase ◽  
Temperature Range ◽  
Forming Limit Curves

The formability of AZ31 magnesium alloy sheets has been investigated in the temperature range varying from 200 to 300°C. Forming limit diagrams have been obtained by performing Nakazima-based tests. The different straining conditions have been investigated using sheet blanks with several length to width ratios. The forming limit curves have been related to the microstructural evolution occurring during deformation. The forming limit diagrams have shown a remarkable increase in formability with temperature that could be related to the occurrence of full dynamic recrystallization at 300°C.

Investigation on the Effects of Sheet Thickness and Deformation Temperature on the Forming Limits of Boron Steel 22MnB5

2011 ◽  
Vol 474-476 ◽  
pp. 993-997 ◽  
Author(s):  
Jia Yue Li ◽  
Jun Ying Min ◽  
Kai Yu Qin ◽  
Jian Pin Lin ◽  
Fu Qiang Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Sheet Thickness ◽  
Forming Limit ◽  
Boron Steel ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Forming Limits ◽  
Half Angle ◽  
Forming Temperature ◽  
Effects Of Temperature

To study the effects of temperature and thickness on forming limits of boron steel 22MnB5, Nakajima tests have been performed for the steels with thickness of 1.0mm and 1.4mm at 600°C and 700°C, respectively. The forming limit curve (FLC) of the steel at 700°C is higher than that at 600°C, and the FLC of the steel with 1.4mm is higher than that of the steel with 1.0mm. With increasing the forming temperature, the strain rate sensitive exponent m increases, and it results in a longer Swift’s diffuse instability phase and greater limit strains. The effect of thickness on yield path is different from the case at room temperature, due to the half angle of pointed Vertex, θ0, which increases with increasing of the thickness, and then the limit strains increase.

Effect of Strain to the Microstructure and Texture of AZ31 Magnesium Alloy during Compression Deformation at Room Temperature

2014 ◽  
Vol 893 ◽  
pp. 387-391
Author(s):  
Shan Jiang ◽  
Bin Zeng ◽  
Lyes Douadji
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Optical Microscope ◽  
Az31 Magnesium Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compression Direction ◽  
Different Strains ◽  
Strain Increase ◽  
Electronic Microscope

AZ31 magnesium alloy samples were compressed to different strains at room temperature and examined through the optical microscope, X-ray diffraction (XRD) and scanning electronic microscope. The results show that the produced twins were mainly the {102} type, and then the {101} type and {102}-{101} type. The size and amount of the twins increased with the strains growth, and after the saturation of twins in the grains the samples fractured. The compressed texture with the basal planes perpendicular to the compression direction also become stronger with strain increase. The {102} twinning deformation played an important role in changing the microstructure and properties of the magnesium alloy at room temperature.

Predicting forming limit diagrams for AZ31 magnesium alloy and 7050 aluminum alloy by numerical simulation

2020 ◽  
pp. 030932472098120
Author(s):  
Fengmei Xue ◽  
Yu Yan ◽  
Jincheng Kang
Keyword(s):  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Forming Limit Diagram ◽  
Az31 Magnesium Alloy ◽  
Instability Criterion ◽  
Forming Limit ◽  
Punch Force ◽  
Forming Limit Diagrams ◽  
Adjacent Element ◽  
7050 Aluminum Alloy

Forming limit diagram (FLD) is the most intuitive method to evaluate and analyze the forming performance of sheet metal, which is widely used in production. To examine the formability of AZ31 magnesium alloy and 7050 aluminum alloy, the simplified bulging models based on the Nakazima experiment are established by ABAQUS finite element (FE) software, and the maximum punch force criterion is adopted as the instability criterion. The forming limit diagrams of 7050 high-strength aluminum alloy at room temperature and AZ31 magnesium alloy at warm working conditions are obtained by extracting the in-plane strain of the adjacent element of the maximum strain element at the moment of instability. Compared with experimental observation shows that the Nakazima virtual model established in this paper can accurately predict FLD. In addition, the influences of lubrication conditions and virtual punching speeds on the bulging process of AZ31 and AA7050 sheet metals are also investigated. The results show that the better the lubrication environment, or the lower the punching speed, the better the formability of the sheet, and reducing the punching speed has a more significant improvement effect on the formability of AZ31 sheets.

Quantitative analysis on friction stress of hot-extruded AZ31 magnesium alloy at room temperature

2018 ◽  
Vol 34 (10) ◽  
pp. 1765-1772 ◽  
Author(s):  
Ling Wang ◽  
Yiquan Zhao ◽  
Jing Zhang ◽  
Ru Ma ◽  
Yandong Liu ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Friction Stress ◽  
Az31 Magnesium Alloy

Enhanced Grain-Boundary Sliding at Room Temperature in AZ31 Magnesium Alloy

2003 ◽  
Vol 419-422 ◽  
pp. 237-242 ◽  
Author(s):  
R. Ohyama ◽  
Junichi Koike ◽  
T. Kobayashi ◽  
Mayumi Suzuki ◽  
Kouichi Maruyama
Keyword(s):  
Magnesium Alloy ◽  
Grain Boundary ◽  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Az31 Magnesium Alloy ◽  
Boundary Sliding

Texture of AZ31 Magnesium Alloy Sheet Heavily Rolled by High Speed Warm Rolling

2007 ◽  
Vol 539-543 ◽  
pp. 3359-3364 ◽  
Author(s):  
Tetsuo Sakai ◽  
Hiroshi Utsunomiya ◽  
H. Koh ◽  
S. Minamiguchi
Keyword(s):  
Magnesium Alloy ◽  
High Speed ◽  
Room Temperature ◽  
Alloy Sheet ◽  
Rolling Temperature ◽  
Az31 Magnesium Alloy ◽  
Basal Texture ◽  
Double Peak ◽  
Magnesium Alloy Sheet ◽  
Az31 Magnesium Alloy Sheet

Magnesium alloy sheets had to be rolled at elevated temperature to avoid cracking. The poor workability of magnesium alloy is ascribed to its hcp crystallography and insufficient activation of independent slip systems. Present authors have succeeded in 1-pass heavy rolling of AZ31 magnesium alloy sheet below 473K by raising rolling speed above 1000m/min. Heavy reduction larger than 60% can be applied by 1-pass high speed rolling even at room temperature. The improvement of workability at lower rolling temperature is due to temperature rise by plastic working. The texture of heavily rolled AZ31 magnesium alloy sheet is investigated in the present study. The texture of sheets rolled 60% at room temperature was <0001>//ND basal texture. At the rolling temperature above 373K, the peak of (0001) pole tilted ±10-15 deg toward RD direction around TD axisto form a double peak texture. The texture varied through thickness. At the surface, the (0001) peak tilted ±10-15 deg toward TD direction around RD axis to form a TD-split double peak texture. The direction of (0001) peak splitting rotated 90 deg from the surface to the center of thickness. Heavily rolled magnesium alloy sheets have non-basal texture. The sheets having non-basal texture are expected to show better ductility than sheets with basal texture.

Evaluation of Plastic Workability Limit of Magnesium Alloy by Cavitations in High Temperature Uni and Biaxial Test

2012 ◽  
Vol 735 ◽  
pp. 67-72
Author(s):  
Kunio Funami ◽  
Daisuke Yamashita ◽  
Kohji Suzuki ◽  
Masafumi Noda
Keyword(s):  
Fine Structure ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Grain Boundary ◽  
Room Temperature ◽  
Grain Boundary Sliding ◽  
Az31 Magnesium Alloy ◽  
Temperature Deformation ◽  
Alloy Plate ◽  
Boundary Sliding

Abstract. This study examined the critical plastic formability limit of a fine-structure AZ31 magnesium alloy plate under warm and high temperature based on the strength of a magnesium alloy that has cavities at room temperature. The cyclic hot free-forging process as pre-form working following rolling at a light reduction ratio fabricated a fine-structure AZ31 magnesium alloy plate. The appearance of the cavities was examined in detail together with changes in the structure and preparation methods before further damage at high temperatures with increasing uni-and biaxial plastic deformation. The allowable deformation limit in the super plasticity process can be estimated from the strength of the deformed material and forming limit diagram (FLD) at room temperature. During high-temperature deformation, cavities are produced by stress concentrations at grain boundary triple points and striation bands due to grain boundary sliding. The cavitations growth behavior is dependent upon deformation conditions, and a high percentage of large cavities occupy the sample surface as a large amount of grain boundary sliding is present, i.e., as uniform elongation grows larger, the cavity size also increases. In a case where 200% uniaxial strain was applied to a fine-grained structure material at a temperature of 623K under a strain rate of 10-4s-1, the tensile strength at room temperature decreased about 13%, and elongation was 10% less, compared with that of a material to which no load was applied due to the influence of cavities. In a case of biaxial deformation, the values were 28% lower. It is possible to draw a FLD based on the cavity incidence fraction .

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