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.

A Finite Element Model for the Prediction of Chip Formation and Surface Morphology in Friction Stir Welding Process

2021 ◽  
pp. 1-21
Author(s):  
Debtanay Das ◽  
Swarup Bag ◽  
Sukhomay Pal ◽  
M. Ruhul Amin
Keyword(s):  
Finite Element ◽  
Friction Stir Welding ◽  
Surface Morphology ◽  
Chip Formation ◽  
Material Flow ◽  
Welding Process ◽  
Measured Temperature ◽  
Material Loss ◽  
Friction Stir ◽  
Mass Scaling

Abstract Friction stir welding (FSW) is widely recognized green manufacturing process capable of producing good quality welded joints at temperature lower than the melting point. However, most of the works is focused on to the establishment of the process parameters for a defect-free joint. There is a lack to understand the formation of defects from physical basis and visualization of the same, which is otherwise difficult to predict by means of simple experiments. The conventional models do not predict chip formation and surface morphology by accounting the material loss during the process. Hence, a 3D finite element based thermo-mechanical model is developed following Coupled Eulerian-Lagrangian (CEL) approach to understand surface morphology by triggering material flow associated with tool-material interaction. In the present quasi-static analysis, the mass scaling factor is explored to make the model computationally feasible by varying the FSW parameter of plunge depth. The simulated results are validated with experimentally measured temperature and surface morphology. In CEL approach, the material flow out of the workpiece enables the visualization of the chip formation, whereas small deformation predict the surface quality of the joint.

Material flow and void defect formation in friction stir welding of aluminium alloys

2018 ◽  
Vol 23 (8) ◽  
pp. 677-686 ◽  
Author(s):  
X. H. Zeng ◽  
P. Xue ◽  
D. Wang ◽  
D. R. Ni ◽  
B. L. Xiao ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Material Flow ◽  
Defect Formation ◽  
Void Defect ◽  
Friction Stir

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.

Flow, process forces and strains during Friction Stir Welding: A comprehensive First principle approach

2020 ◽  
pp. 095440542097008
Author(s):  
Dhruv Bajaj ◽  
Arshad Noor Siddiquee ◽  
Noor Zaman Khan ◽  
AK Mukhopadhyay ◽  
Sohail M A Khan Mohammed ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Shear Strain ◽  
Material Flow ◽  
Large Scale ◽  
Defect Formation ◽  
First Principle ◽  
Flow Process ◽  
Maximum Shear Strain ◽  
Friction Stir ◽  
Process Forces

Friction stir welding is recent yet spectacular process, which assumes accrescent expanse to evolve as a multi-purpose process. Its potential is greatly being tapped through large-scale experimental and computer simulation-based investigations. Several simulation and empirical models have been proposed but exact fundamental analyses on forces, material flow and strain are still absent. Complexities associated with the process are perhaps the main reason that a fundamental analysis is difficult. A comprehensive analysis of this kind is critical for understanding the evolution of microstructure, mechanical properties of joint and defect formation. This study presents an analysis of material flow, process forces and strains using first principle approach. Results have been presented as exact mathematical expressions in terms of material properties and process parameters. It was demonstrated that the material during stirring experiences direct and shear strains both when it moves from advancing side to retreating side in front of the tool and after rotation deposits behind the tool. It was also demonstrated that the strain significantly reduced from advancing to retreating side; for a typical case the shear strain greater than 10,000% prevails in advancing side and the maximum shear strain on retreating side is of the order of 6000%.

Effect of friction stir welding parameters on the material flow, mechanical properties and corrosion behavior of dissimilar AA5083-AA6061 joints

2021 ◽  
pp. 095440622110361
Author(s):  
Kethavath Kranthi Kumar ◽  
Adepu Kumar ◽  
MVNV Satyanarayana
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Corrosion Behavior ◽  
Process Parameters ◽  
Material Flow ◽  
Stir Zone ◽  
Friction Stir ◽  
Notch Tensile Strength ◽  
Mechanical Properties And Corrosion

Material flow has a significant impact on the joint properties and is one of the most challenging aspects to be understood in dissimilar friction stir welding. The present study emphasizes the role of process parameters on material flow, mechanical properties and corrosion behavior of dissimilar friction stir welds of AA5083-AA6061. Microstructural analysis revealed that the onion ring sub-layer width observed at the stir zone was substantially changed by varying process parameters. It was understood that the higher rotational speeds promote better intermixing and enhanced mechanical properties. The notch tensile strength values were in correlation with the intermixing of materials at the stir zone and the highest notch tensile strength value was obtained at 1400 rpm and 60 mm/min. A remarkable degree of material intermixing and fragmentation of intermetallics at higher rotational speeds resulted in better corrosion resistance.

scholarly journals Defect formation and material flow in Friction Stir Welding

2020 ◽  
Vol 80 ◽  
pp. 103912
Author(s):  
Narges Dialami ◽  
Miguel Cervera ◽  
Michele Chiumenti
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Defect Formation ◽  
Friction Stir

scholarly journals Influence of Tool Tilt Angle on Material Flow and Defect Generation in Friction Stir Welding of AA2219

2018 ◽  
Vol 68 (5) ◽  
pp. 512-518 ◽  
Author(s):  
Suresh Meshram ◽  
Madhusudhan Reddy
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tilt Angle ◽  
Material Flow ◽  
Critical Role ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir ◽  
Tool Tilt Angle ◽  
Welding Processes

Heat treatable aluminium alloy AA2219 is widely used for aerospace applications, welded through gas tungsten and gas metal arc welding processes. Welds of AA2219 fabricated using a fusion welding process suffers from poor joint properties or welding defects due to melting and re-solidification. Friction stir welding (FSW) is a solid-state welding process and hence free from any solidification related defects. However, FSW also results in defects which are not related to solidification but due to improper process parameter selection. One of the important process parameters, i.e., tool tilt angle plays a critical role in material flow during FSW, controlling the size and location of the defects. Effect of tool tilt angle on material flow and defects in FSW is ambiguous. A study is therefore taken to understand the role of tool tilt angle on FSW defects. Variation in temperature, forces, and torque generated during FSW as a result of different tool tilt angles was found to be responsible for material flow in the weld, controlling the weld defects. An intermediate tool tilt angle (1o-2o) gives weld without microscopic defect in 7 mm thick AA2219 for a given set of other process parameters. At this tool tilt angle, x-force, and Z- force is balanced with viscosity and the material flow strain rate sufficient for the material to flow and fill internal voids or surface defects in the weld.

Investigation of material flow and thermomechanical behavior during friction stir welding of an AZ31B alloy for threaded and unthreaded pin geometries using computational solid mechanics simulation

2020 ◽  
pp. 095440622096254
Author(s):  
RAR Giorjao ◽  
EB Fonseca ◽  
JA Avila ◽  
EF Monlevade ◽  
AP Tschiptschin
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Solid Mechanics ◽  
Defect Formation ◽  
Welding Process ◽  
High Sensitivity ◽  
Thermomechanical Behavior ◽  
Welding Parameters ◽  
Arbitrary Lagrangian Eulerian ◽  
Friction Stir

In the friction stir welding process, the tool role in the material flow and its thermomechanical behavior is still not entirely understood. Several modeling approaches attempted to explain the material and tool relationship, but to this date, insufficient results were provided in this matter. Regarding this issue and the urgent need for trustful friction stir welding models, a computational solid mechanic's model capable of simulating material flow and defect formation is presented. This model uses an Arbitrary Lagrangian-Eulerian code comparing a threaded and unthread pin profile. The model was able to reproduce the tool's torque, temperatures, and material flow along the entire process, including the underreported downward flow effect promoted by threaded pin's. A point tracking analysis revealed that threads increase the material velocity and strain rate to almost 30% compared to unthreaded conditions, promoting a temperature increment during the process, which improved the material flow and avoided filling defects. The presented results showed the model's capability to reproduce the defects observed in real welded joints, material thermomechanical characteristics and high sensitivity to welding parameters and tool geometries. Nevertheless, the outcomes of this work contribute to essential guidelines for future friction stir welding modeling and development, tool design, and defect prediction.

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