Investigation on the Effects of Process Parameters on Defect Formation in Friction Stir Welded Samples via Predictive Numerical Modeling and Experiments

2017 ◽  
Author(s):  
Abhishek Ajri ◽  
Yung C. Shin
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Defect Formation ◽  
Welding Process ◽  
Weld Strength ◽  
Friction Stir Weld ◽  
Optimum Process ◽  
Friction Stir ◽  
Different Types ◽  
Induced Flow

Setting optimum process parameters is very critical in achieving a sound friction stir weld joint. Understanding the formation of defects and developing techniques to minimize them can help in improving the overall weld strength. The most common defects in friction stir welding are tunnel defects, cavities and excess flash formation which are caused due to incorrect tool rotational or advancing speed. In this paper, the formation of these defects is explained with the help of an experimentally verified 3D finite element model. It was observed that the asymmetricity in temperature distribution varies for different types of defects formed during friction stir welding. The location of the defect also changes based on the shoulder induced flow and pin induced flow during friction stir welding. Besides formation of defects like excess flash, cavity defects, tunnel/wormhole defects, two types of groove like defects are also discussed in this paper. By studying the different types of defects formed, a methodology is proposed to recognize these defects and counter them by modifying the process parameters to achieve a sound joint for a displacement based friction stir welding process.

Investigation on the Effects of Process Parameters on Defect Formation in Friction Stir Welded Samples Via Predictive Numerical Modeling and Experiments

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Abhishek Ajri ◽  
Yung C. Shin
Keyword(s):  
Process Parameters ◽  
Defect Formation ◽  
Weld Strength ◽  
Friction Stir Weld ◽  
Optimum Process ◽  
Fe Model ◽  
Friction Stir ◽  
Different Types ◽  
Induced Flow ◽  
Displacement Based

Setting optimum process parameters is very critical in achieving a sound friction stir weld joint. Understanding the formation of defects and developing techniques to minimize them can help in improving the overall weld strength. The most common defects in friction stir welding (FSW) are tunnel defects, cavities, and excess flash formation, which are caused due to incorrect tool rotational or advancing speed. In this paper, the formation of these defects is explained with the help of an experimentally verified 3D finite element (FE) model. It was observed that the asymmetricity in temperature distribution varies for different types of defects formed during FSW. The location of the defect also changes based on the shoulder induced flow and pin induced flow during FSW. Besides formation of defects like excess flash, cavity defects, tunnel/wormhole defects, two types of groove like defects are also discussed in this paper. By studying the different types of defects formed, a methodology is proposed to recognize these defects and counter them by modifying the process parameters to achieve a sound joint for a displacement-based FSW process.

Optimization of Friction Stir Welding Process Parameters to Join Al 5052 and Al 6061 Alloy Plates Using Grey-Taguchi Technique

2017 ◽  
Author(s):  
R. Sandeep ◽  
D. Sudhakara ◽  
G. Prasanthi
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Fusion Welding ◽  
Optimum Process ◽  
Friction Stir ◽  
Friction Stir Welding Process ◽  
Grey Analysis ◽  
Grey Taguchi

Friction stir welding (FSW) is a solid state welding process used for welding similar and dissimilar materials. The process is widely used because it does not have common problems such as solidification and liquefaction cracking associated with the fusion welding techniques. The objective of the present research is to find the best combination of friction stir welding process parameters to join aluminium 5052 and 6061 alloy materials. The combination of process parameters is helpful to improve ultimate tensile strength, yield strength, percentage of elongation and hardness of welded joint. To achieve the research objective taguchi based grey analysis was used. The optimum process parameters were found be at rotational speed is 1400 rpm, transverse speed of 100 mm/min and axial force is at 11 KN.

Prediction of Surface Profile in Friction Stir Welding Using Coupled Eulerian and Lagrangian Method

2020 ◽  
Author(s):  
Debtanay Das ◽  
Swarup Bag ◽  
Sukhomay Pal ◽  
M. Ruhul Amin
Keyword(s):  
Friction Stir Welding ◽  
Surface Morphology ◽  
Process Parameters ◽  
Chip Formation ◽  
Material Flow ◽  
Defect Formation ◽  
Current Model ◽  
Surface Profile ◽  
Green Technology ◽  
Friction Stir

Abstract Friction stir welding (FSW) is widely accepted by industry because of multiple advantages such as low-temperature process, green technology, and capable of producing good quality weld joints. Extensive research has been conducted to understand the physical process and material flow during FSW. The published works mainly discussed the effects of various process parameters on temperature distribution and microstructure formation. There are few works on the prediction of defect formation from a physics-based model. However, these models ignore chip formation or surface morphology and material loss during the FSW process. In the present work, a fully coupled 3D thermo-mechanical model is developed to predict the chip formation and surface morphology during welding. The effects of various process parameters on surface morphology are also studied using the current model. Coupled Eulerian-Lagrangian (CEL) technique is used to model the FSW process using a commercial software ABAQUS. The model is validated by comparing the results in published literature. The current model is capable of predicting the material flow out of the workpiece and thus enables the visualization of the chip formation. The developed model can extensively be used to predict the surface quality of the friction stir welded joints.

scholarly journals Analysis of the influence of position of welding materials on the FSW seams properties for three dissimilar aluminium alloy

2018 ◽  
Vol 178 ◽  
pp. 03003 ◽  
Author(s):  
Ana Bosneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Workpiece Material ◽  
Friction Stir ◽  
Welding Joints ◽  
Welding Materials

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.

Optimization of Welding Process Parameters in Novel Friction Stir Welding of Polyamide 66 Joints

2019 ◽  
Vol 969 ◽  
pp. 828-833 ◽  
Author(s):  
R. Nandhini ◽  
R. Dinesh Kumar ◽  
S. Muthukumaran ◽  
S. Kumaran
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Polyamide 66 ◽  
Friction Stir ◽  
Response Characteristics ◽  
Tool Shoulder ◽  
Stereo Microscope ◽  
Friction Plate

The friction stir welding of polyamide 66 with a specially modified tool is studied. A variation of the conventional friction stir welding is investigated by incorporating a friction plate for the purpose of heating the polymer in the course of welding process through the tool shoulder. This in turn, improves the efficiency of the weld. The association of the welding process parameters and the weld performance has been investigated by the grey relational analysis with multi response characteristics like weld tensile strength, percent elongation and hardness. Macrostructure of the weld joint cross section has been explored by Stereo microscope. The maximum weld tensile strength of 63 MPa and a Shore hardness of 60 D at the weld nugget are obtained. The hardness profiles of the welded samples have been analyzed in this investigation.

scholarly journals Experimental Investigation of Friction Stir Welding on 6061-T6 Aluminum Alloy using Taguchi-Based GRA

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1480
Author(s):  
Assefa Asmare ◽  
Raheem Al-Sabur ◽  
Eyob Messele
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Weight Ratio ◽  
Welding Process ◽  
Quality Criteria ◽  
Alloy Sheet ◽  
Friction Stir ◽  
Weld Joints

The use of aluminum alloys, nowadays, is swiftly growing from the prerequisite of producing higher strength to weight ratio. Lightweight components are crucial interest in most manufacturing sectors, especially in transportation, aviation, maritime, automotive, and others. Traditional available joining methods have an adverse effect on joining these lightweight engineering materials, increasing needs for new environmentally friendly joining methods. Hence, friction stir welding (FSW) is introduced. Friction stir welding is a relatively new welding process that can produce high-quality weld joints with a lightweight and low joining cost with no waste. This paper endeavors to deals with optimizing process parameters for quality criteria on tensile and hardness strengths. Samples were taken from a 5 mm 6061-T6 aluminum alloy sheet with butt joint configuration. Controlled process parameters tool profile, rotational speed and transverse speed were utilized. The process parameters are optimized making use of the combination of Grey relation analysis method and L9 orthogonal array. Mechanical properties of the weld joints are examined through tensile, hardness, and liquid penetrant tests at room temperature. From this research, rotational speed and traverse speed become significant parameters at a 99% confidence interval, and the joint efficiency reached 91.3%.

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