Superplastic Forming Response of a Friction Stir Processed Mg Alloy Sheet – A Numerical Approach

2012 ◽  
Vol 735 ◽  
pp. 192-197 ◽  
Author(s):  
Mohammad Albakri ◽  
Bilal Mansoor ◽  
Ahmad Albakri ◽  
Marwan Khraisheh
Keyword(s):  
Thickness Distribution ◽  
Base Material ◽  
Superplastic Forming ◽  
Numerical Approach ◽  
Processing Technique ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Dome Height ◽  
Friction Stir ◽  
Forming Characteristics

Friction stir process (FSP) is a severe plastic deformation based secondary processing technique that can be utilized to engineer novel microstructures in metallic alloys. It is well known that such techniques are cumbersome and require significant experimental work and material to determine optimum processing conditions. Therefore in this work, we propose a new two step numerical approach, where: (i) CFD simulations coupled with Zener-Holloman relation are used to predict microstructure evolution in stirred, transition and heat affected zones of friction stir processed AZ31 Mg alloy sheets, (ii) Finite element simulations are carried out to evaluate superplastic forming characteristics of different microstructures developed after FSP. Simulation trends including forming pressure profiles, dome height evolution, and thickness distribution of friction stir processed sheets are compared with those of the base material. The proposed combination of numerical approaches to model both processing and forming aspects yields a powerful tool to study and optimize processing and forming technologies with limited experimentation.

Microstructures and Properties of FSW Joints of AZ31B Mg Alloy

2011 ◽  
Vol 291-294 ◽  
pp. 855-859 ◽  
Author(s):  
Si Rong Yu ◽  
Xian Jun Chen
Keyword(s):  
Mechanical Properties ◽  
Heat Affected Zone ◽  
Welded Joint ◽  
Base Material ◽  
Alloy Sheet ◽  
Weld Nugget ◽  
Mg Alloy ◽  
Material Strength ◽  
Nugget Zone ◽  
Friction Stir

The extruded AZ31B Mg alloy sheet was welded with friction stir welding. The microstructures and mechanical properties of the welded joint were investigated. The results show that the grains in the weld nugget zone were small, uniform and equiaxed. The grains in thermo-mechanical affected zone were stretched and relatively small, but were not as small and uniform as those in the weld nugget zone. The grains in the heat-affected zone were relatively coarse. The fracture of the welded joint occurred mainly in the heat affected zone. The tensile strength of the welded joints was up to 257.4 MPa and was 87.9% of the base material strength. The microhardness in the weld nugget zone was higher. The microhardness in the thermo-mechanical affected zone and heat affected zone were lower than that in the weld nugget zone. The microhardness in the weld nugget zone increased from the upper surface to the bottom.

Microstructure and Texture Evolution during Friction Stir Processing of AZ31 Mg Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 1195-1200 ◽  
Author(s):  
Ren Long Xin ◽  
Bo Li ◽  
Qing Liu
Keyword(s):  
Grain Size ◽  
Texture Evolution ◽  
Base Material ◽  
Alloy Sheet ◽  
Electron Back Scatter Diffraction ◽  
Mg Alloy ◽  
Gradual Change ◽  
Friction Stir ◽  
Az31 Mg Alloy ◽  
Average Grain Size

In this study, a well-textured AZ31 Mg alloy sheet was friction stir (FS) processed, and the microstructure and texture evolution in various regions of the processed alloy were examined by optical microscopy (OM) and electron back scatter diffraction (EBSD). The results showed that the grain size in the FS zone was significantly refined compared to that in the base material (BM). The average grain size in the thermomechanically affected zone (TMAZ) and heat-affected zone (HAZ) was comparable with that in the BM. There is a gradual change of local texture from BM to FS zone due to plastic flow together with heating input during the FS processing. The <0002> direction was roughly parallel to the cylindrical pin surface normal of the FS zone. The <0002> direction in the HAZ is similar to that in the BM, but more diffuse. The <0002> direction in the TMAZ was tilted 25~30o away from the ND and there is a distinct boundary between the FS zone and TMAZ at the advancing side which introduced an incompatibility between the FS zone and TMAZ. This might explain the fact that the transverse FS processed Mg alloys commonly fracture at the advancing side during tensile tests.

Superplastic Behavior and Microstructure of Titanium (Ti-6Al-4V) Friction Stir Welds Made under a Variety of Processing Conditions

2010 ◽  
Vol 433 ◽  
pp. 169-176 ◽  
Author(s):  
Paul Edwards ◽  
Mamidala Ramulu ◽  
Daniel G. Sanders
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Superplastic Forming ◽  
Spindle Speed ◽  
Processing Conditions ◽  
Superplastic Behavior ◽  
Friction Stir ◽  
Fine Grained ◽  
Weld Parameters

Friction Stir Welding of Ti-6Al-4V was performed on 5 mm thickness plate in order to assess the affect of welding conditions on the resulting microstructure and superplastic forming behavior of the joints. A variety of welding conditions were tested and all welds were subsequently Superplastically formed. It was found that the weld parameters do influence the microstructure and degree of superplastic performance of the joints. Spindle speed was found to have the most dominant affect on the resulting microstructure and superplastic forming behavior. Low spindle speed welds lead to fine grained microstructures and highly superplastic welds, relative to the base material, while high spindle speed welds larger grained microstructures and less superplastic welds.

Fatigue behavior of friction stir spot welded AZ31 Mg alloy sheet joints

2013 ◽  
Vol 23 (7) ◽  
pp. 1949-1956 ◽  
Author(s):  
Tian-jiao LUO ◽  
Bao-liang SHI ◽  
Qi-qiang DUAN ◽  
Jun-wei FU ◽  
Yuan-sheng YANG
Keyword(s):  
Fatigue Behavior ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Friction Stir ◽  
Az31 Mg Alloy ◽  
Spot Welded

Numerical Simulation of Bulging Process of Aluminum Alloy Sheet

2013 ◽  
Vol 327 ◽  
pp. 112-116 ◽  
Author(s):  
Mao Ting Li ◽  
Yong Zhang ◽  
Chui You Kong
Keyword(s):  
Aluminum Alloy ◽  
Material Flow ◽  
Thickness Distribution ◽  
Superplastic Forming ◽  
Alloy Sheet ◽  
Pressure Loading ◽  
Forming Process ◽  
Element Analysis ◽  
Danger Zone ◽  
Linear Finite Element

Basing on software MSC. Marc of non-linear finite element analysis, the article has studied the material flow in the process of aluminum alloy superplastic gas bulging forming. By analyzing of the thickness distribution of the molding member it confirm the danger zone in the forming process. By analyzing of pressure loading curve influence on forming part. Because the aluminum alloy is widely used in the industrial departments, it is supposed to improve the ability of forming ability of aluminum alloy by researching the superplastic forming.

Superplastic Forming Characteristics of a Fine-Grained Cu-Based Shape Memory Alloy

2012 ◽  
Vol 579 ◽  
pp. 22-31
Author(s):  
Chin Chuan Hsu
Keyword(s):  
Superplastic Forming ◽  
Rate Of Change ◽  
Dome Height ◽  
Base Line ◽  
Fine Grained ◽  
Forming Temperature ◽  
Forming Characteristics ◽  
Temperature And Pressure ◽  
Increasing Temperature ◽  
Free Bulging

The influences of temperature and pressure on the blow forming of CuZnAlZr sheet was investigated under free bulging conditions using argon gas. The effects evaluated were the dome height, measured at the dome apex; the specific thickness, the ratio of the actual thickness to the initial thickness; and the thinning factor, the ratio of the actual thickness to the average thickness. The results show that the dome height and the rate of change of dome height with respect to time, dh/dt, increase with increasing temperature and/or pressure. The specific thickness decreases with increasing fractional height (the ratio of the height of a given point above the base line to the height of the apex), and the specific thickness at the apex decreases with increasing temperature and/or pressure as well. The thinning factor decreases with increasing fractional height. Furthermore, this decrease becomes more significant with an increase in either the forming temperature or pressure. The thinning factor at the apex, as a function of the height to base ratio for all conditions falls into the region between m=0.3 and m=0.75 curves.

Numerical Analysis on Superplastic Forming of Friction Stir Welded AA6061-T6 Alloy Sheet

2012 ◽  
Vol 488-489 ◽  
pp. 753-758 ◽  
Author(s):  
P. Ganesh ◽  
V.S. Senthil Kumar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Constant Pressure ◽  
Pressure Coefficient ◽  
Superplastic Forming ◽  
Element Model ◽  
Alloy Sheet ◽  
Element Analysis ◽  
Friction Stir ◽  
Finite Element Software

The friction stir welded superplastic forming of AA6061-T6 sheet has been numerically analyzed based on the experimental and finite element software. A selected range of tool rotating speeds of 500, 1000 and 2000 rpm was used for friction stir welding. At constant temperature of 550O C and constant pressure of 0.4 Mpa, superplastic forming experiments was performed using free forming die for the friction stir welded sheets. A detailed 3D element type study has been performed in the finite element analysis. The proposed finite element model has been validated in comparison with experimental data. The results are found to have reasonably good agreement between simulations and experiment. The effect of constant pressure, coefficient of friction, strainrate and strain-rate sensitivity has been studied using the proposed finite element model.

Improved Recrystallization Resistance and Welding Properties of Cold-Rolled Al-Mg Alloy Sheets by Microalloying with Sc and Zr

2021 ◽  
Vol 1035 ◽  
pp. 17-24
Author(s):  
Hao Wu ◽  
Zhi Kai Zheng ◽  
Si Meng Ren ◽  
Shu Lei Li ◽  
Hu Wang ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Welded Joints ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Softening Effect ◽  
Welding Temperature ◽  
Friction Stir ◽  
Alloy Increase ◽  
Welding Properties ◽  
Zr Alloy

The effects of Sc and Zr element on the recrystallization behavior and microstructure evolution of Al-Mg alloy had been researched in this paper, and meanwhile, the microstructure and mechanical properties of the friction stir welding joints were also analyzed. The results show that the recrystallization and grain growth behavior of Al-Mg-Sc-Zr alloy can be inhibited effectively by microalloying with Sc and Zr. Compared with Al-Mg and Al-Mg-Zr alloys, the recrystallization start temperature and finish temperature of Al-Mg-Sc-Zr alloy increase significantly, and the strength of alloy sheet which subjected to stabilizing annealing is increased by more than 50MPa. Moreover, the recrystallization softening effect of the welded joints microstructure, which caused by the welding temperature field and welding heat input, can be weaken by microalloying with Sc and Zr, the width of recrystallization zone is reduced, the microstructure and properties of the welded joints are improved. The friction stir welding coefficients of Al-Mg-Sc-Zr alloy increases to 86.9%.

Numerical-Experimental Characterization of a Superplastic AZ31 Magnesium Alloy

2007 ◽  
Vol 551-552 ◽  
pp. 317-322 ◽  
Author(s):  
G. Palumbo ◽  
Donato Sorgente ◽  
Luigi Tricarico ◽  
S.H. Zhang ◽  
W.T. Zheng ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Biaxial Tension ◽  
Thickness Distribution ◽  
Alloy Sheet ◽  
Experimental Results ◽  
Az31 Magnesium Alloy ◽  
Dome Height ◽  
Fe Model ◽  
Flow Parameters ◽  
Hot Rolled

In this work the superplastic behaviour of a hot rolled AZ31 magnesium alloy sheet under a biaxial tension test with the blow forming technique is presented and reported. The specimen dome height and its thickness distribution, during and after the test, have been used as characterizing parameters. A numerical FE model of the test has been developed in order to easily characterize the material and to directly analyze experimental results. The influence of the rolling cycle on the microstructure and consequently on the material behaviour has been also analyzed. A synergic use of experimental results and of the numerical model has been done for finding material constants in different situations. The material flow parameters have been found and results are presented.

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