Optimisation of submerged friction stir welding parameters of aluminium alloy using RSM and GRA

Author(s):  
C. Rathinasuriyan ◽  
V.S.Senthil Kumar
2014 ◽  
Vol 59 (1) ◽  
pp. 385-392
Author(s):  
B. Rams ◽  
A. Pietras ◽  
K. Mroczka

Abstract The article presents application of FSW method for joining elements made of cast aluminium alloys which are hardly weldable with other known welding techniques. Research’s results of plasticizing process of aluminium and moulding of seam weld during different FSW process’ conditions were also presented. Influence of welding parameters, shape and dimensions of tool on weld structure, welding stability and quality was examined. Application of FSW method was exemplified on welding of hemispheres for valves made of cast aluminium alloy EN AC-43200.


2012 ◽  
Vol 445 ◽  
pp. 789-794 ◽  
Author(s):  
Vahid Moosabeiki ◽  
Ghasem Azimi ◽  
Mostafa Ghayoor

Friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force, etc., and tool pin profile play a major role in deciding the weld quality. Friction stir tool plays a major role in friction stir welding process. In this investigation, it is tried to evaluate the effect of tool pin thread and tool shoulder curvature on FSW zone formation in AA6061 aluminium alloy. In this regard, six different tool pin geometries (threadless triangular pin with/without conical shoulder, threaded triangular pin with conical shoulder, threadless square pin with/without conical shoulder, threaded square pin with conical shoulder) are used to fabricate the joints. The formation of FSP zones are analyzed macroscopically. Tensile properties of the joints are evaluated and correlated with the FSP zone formation. Consequently, it is obtained that welding creates a higher quality compared to other tool pin profiles using the square tool with curved shoulder and having threaded pin.


2007 ◽  
Vol 558-559 ◽  
pp. 477-483 ◽  
Author(s):  
Sandrine Bozzi ◽  
Anne Laure Etter ◽  
Thierry Baudin ◽  
A. Robineau ◽  
Jean Claude Goussain

At the prospect of a lightening of the automobile structures, welded spots have been realized on a stacking of two sheets (a 6008 aluminium alloy on steel) by Friction Stir Welding (FSW). Different process parameters have been tested but only the influence of the dwell time will be described in the present paper. The dwell time corresponds to the time during which the probe stays in rotation at its bottom location before extracting. A study of the microstructures and the crystallographic textures associated to mechanical tests (shear and tensile tests) allowed to determine the best set of welding parameters. The recrystallized area around the welding spot has been characterized by Electron BackScattered Diffraction (EBSD). The aim of the present work is to identify the recrystallization mechanisms which occur during welding, and to understand the influence of the dwell time on the recrystallized area. A mechanism of continuous dynamic recrystallization has been identified since misorientation of sub-boundary increases close to the weld and this for all the dwell times tested. Elsewhere, it has been found that the increase of the dwell time induces a larger recrystallized zone.


Friction stir welding has proven to be the most promising solid state joining process. It can be used to get high weldability in joining of high strength aerospace aluminium alloys and other metallic alloys which used to be low with traditional fusion welding process. This paper emphasises on finding the optimum process parameter for friction stir welding of dissimilar aluminium alloy AA6061 to AA5183 using multi criteria decision making method (MCDM). Friction stir welding was done at different tool rotational speed and transverse velocity and mechanical properties such as tensile strength, percentage elongation and hardness were studied for each weld specimen. Finally optimization was done using TOPSIS (Techniqueof Ordered Preference by Similarity to Ideal Solution). The result revealed that the tool rotational speed of 1200 rpm and welding speed of 80mm/min are the optimum welding parameters.


Author(s):  
Boddu Rajnaveen ◽  
Govada Rambabu ◽  
Kollabothina Prakash ◽  
Kotipalli Srinivasa Rao

Abstract AA2219-T87 aluminium alloy has been used in aerospace applications because of its high strength, low density and resistance to corrosion. The copper in the alloy improves the hardness and lowers melting point, which makes two sections easily joined with a process called friction stir welding of aluminium alloy. In the present work, heat-treated AA2219 alloy was butt welded by solid-state friction stir welding process. This work aims to develop a suitable combination of welding parameters for producing defect-free weld joints of AA2219 alloy to improve tensile and corrosion properties. The most influencing control parameter for optimising the friction stir welding responses was determined using sophisticated design of experiments (DOE) techniques. Ultimate tensile strength and corrosion resistance are observed as responses in this study. To achieve the desired weld responses, a three-factor, three-level Box-behneken design was used. Analysis of Variance (ANOVA) was carried out to examine the interaction effect and significant welding parameter to set the optimal level of welding conditions. Multi-response regression equations have been developed using response surface methodology (RSM) to estimate the output characteristics of weld. The Genetic algorithm (GA) was used to optimise the predicted mathematical model under given optimization constraints. The results shown that the optimum responses are obtained at input factors rotational speed 300 rpm, welding speed 80 mm/min, and axial force of 10kN.


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