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

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 An Alternative Pressure-dependent Friction Boundary Condition for Modeling Self-reacting Friction Stir Welding

2021 ◽  
Author(s):  
CHENYU ZHAO ◽  
Xun Liu
Keyword(s):  
Boundary Condition ◽  
Friction Stir Welding ◽  
Cross Section ◽  
Welding Speed ◽  
Defect Formation ◽  
Computational Results ◽  
Weld Formation ◽  
Void Defect ◽  
Friction Stir ◽  
Cross Section Geometry

Abstract A pressure-dependent friction boundary condition is developed based on wear theory for modeling self-reacting friction stir welding using computational fluid dynamics approach. The importance of shear layer in weld formation is emphasized. Effects of welding speed on the weld cross section geometry can be robustly captured with this newly developed boundary condition. Computational results showed at higher welding speed, the distance between the TMAZ boundary and the pin periphery at the advancing side is reduced, which corresponds to the experimental observations. This tendency could serve as a numerical criterion to predict void defect formation.

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%.

Metallurgical Nature at the Interface between Tool Shoulder and Workpiece during Friction Stir Welding

2007 ◽  
Vol 29-30 ◽  
pp. 43-46
Author(s):  
Zhan W. Chen ◽  
Timotius Pasang ◽  
Q. Yin ◽  
R. Peris
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Material Flow ◽  
Intermetallic Layer ◽  
Contact Condition ◽  
Sliding Contact ◽  
Metallographic Examination ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Fsw Experiments

Knowledge on the contact condition at the tool/workpiece interface is essential for understanding many aspects of FSW. In the present study, FSW experiments were conducted using aluminium alloys followed by metallographic examination focusing on the tool shoulder-workpiece interface region. It was observed that an interfacial intermetallic layer and hence metallurgical sticking/soldering readily formed. Temperature measurements have suggested the presence of interface liquid, hence suggesting a mechanical sliding contact condition dominant. This has been supported by the observation on material flow within the shear layer.

scholarly journals Material flow in Friction Stir Welding

2008 ◽  
Vol 14 (S3) ◽  
pp. 87-90 ◽  
Author(s):  
C. Leitão ◽  
R.M. Leal ◽  
D.M. Rodrigues ◽  
P. Vilaça ◽  
A. Loureiro
Keyword(s):  
Plastic Deformation ◽  
Friction Stir Welding ◽  
Automotive Industry ◽  
Aluminium Alloys ◽  
Material Flow ◽  
Dissimilar Materials ◽  
Tool Geometry ◽  
X Ray ◽  
Friction Stir ◽  
Solid State Joining

Friction stir welding (FSW) is a solid-state joining technique initially developed for aluminium alloys. The heat generated by a rotating tool softens the material in the vicinity of the tool. The material undergoes intense plastic deformation following quite complex paths around the tool, depending on the tool geometry, process parameters and material to be welded. The comprehension of the material flow is essential to prevent voids and other internal defects which may form during welding. Several techniques have been used for tracking material flow during FSW such as metallography, the use of a marker material as a tracer or the flow visualization by FSW of dissimilar materials or even the X-ray and computer tomography. Some of these techniques are useless in the analysis of welds in homogenous materials or welds between materials of the same group. The aim of this investigation is tracking the material flow in FSW between 1mm thick sheets in aluminium alloys AA 5182-H111 and AA 6016-T4, currently used in automotive industry.

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

Mathematical Modelling of Material Flow during Friction Stir Welding of Aluminium Alloys

2018 ◽  
Vol 1146 ◽  
pp. 115-120
Author(s):  
Cosmin Ighisan ◽  
Bogdan Radu ◽  
Cristian Ciucă
Keyword(s):  
Mathematical Model ◽  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Material Flow ◽  
Good Precision ◽  
Two Dimensional ◽  
Element Analysis ◽  
Friction Stir ◽  
The Mathematical Model ◽  
Distribution Field

The paper presents the results of a mathematical model of the material flow during Friction Stir Welding (FSW) of aluminium alloys using a Finite Element Analysis. The authors presented their work on a two-dimensional visco-plastic model, using User Define Functions (UDF) in a commercial CFD code (FLUENT). The model developed was validated by microstructural investigations on experimental FSW joints and by a comparative analysis of temperature distribution field of the experimental FSW joint and numerical simulated model. The results confirmed that the mathematical model describes with a good precision the material flow and temperature field during FSW process.

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.

Sign in / Sign up

Export Citation Format

Share Document