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.

scholarly journals Temperature Monitoring and Material Flow Characteristics of Friction Stir Welded 2A14-t6 Aerospace Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3387 ◽  
Author(s):  
Tingke Wu ◽  
Fengqun Zhao ◽  
Haitao Luo ◽  
Haonan Wang ◽  
Yuxin Li
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Model ◽  
Welding Process ◽  
Temperature Monitoring ◽  
Measuring System ◽  
Welding Parameters ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin

Aiming at the problems that the temperature in the welding area of friction stir welding (FSW) is difficult to measure and the joints are prone to defects. Hence, it is particularly important to study the material flow in the welding area and improve the welding quality. The temperature of the tool shoulder and the tool pin was monitored by the wireless temperature measuring system. The finite element model of friction stir welding was established and the welding conditions were numerically simulated. The flow law of material of the friction stir welding process was studied by numerical simulation. The material flow model was established by combining the microstructure analysis results, and the forming mechanism of the defects was analyzed. The results show that the temperature in the welding zone is the highest at 1300 rpm, and the temperature at the tool shoulder is significantly higher than that at the tool pin in the welding stage. When high-rotation speeds (HRS) are chosen, the material beneath the tool shoulder tends to be extruded into the pin stirred zone (PSZ) after flowing back to the advancing side. This will cause turbulence phenomenon in the advancing side of the joint, which will easily lead to the formation of welding defects. In the future, temperature monitoring methods and the flow model of material can be used to optimize the welding parameters.

Effect of Friction Stir Welding Parameters on Thermal and Tensile Behavior of Aluminum Weldments Using Double Shoulder Tools

2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Tensile Behavior ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Base ◽  
Tool Pin ◽  
Strength And Ductility

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.

Thermo-Mechanical Modelling of Friction Stir Welding Process

2013 ◽  
Vol 774-776 ◽  
pp. 1155-1159 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Finite Element Analysis ◽  
Friction Stir Welding ◽  
Mechanical Behaviour ◽  
Material Flow ◽  
Welding Process ◽  
Element Analysis ◽  
Friction Stir ◽  
Mechanical Modelling ◽  
Major Factors ◽  
Realistic Prediction

Friction stir welding (FSW) is a solid-state welding process where no gross melting of the material being welded takes place. Numerical modelling of the FSW process can provide realistic prediction of the thermo-mechanical behaviour of the process. Latest literature relating to finite element analysis (FEA) of thermo-mechanical behaviour of FSW process is reviewed in this paper. The recent development in thermo-mechanical modelling of FSW process is described with particular reference to two major factors that influence the performance of FSW joints: material flow and temperature distribution. The main thermo-mechanical modelling used in FSW process are discussed and illustrated with brief case studies from the literature.

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.

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

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.

Process Parameter Optimization of Friction Crush Welding (FCW) of AISI 304 Stainless Steel

2017 ◽  
Author(s):  
Gurinder Singh Brar ◽  
Manpreet Singh ◽  
Ajay Singh Jamwal
Keyword(s):  
Stainless Steel ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Pressure Vessels ◽  
304 Stainless Steel ◽  
Welding Parameters ◽  
Work Piece ◽  
Aisi 304 Stainless Steel ◽  
Aisi 304 ◽  
Friction Stir

AISI 304 stainless steel is one of the grades of steel widely used in engineering applications particularly in chemical equipments, food processing, pressure vessels and paper industry. Friction crush welding (FCW) is type of friction welding, where there is a relative motion between the tool and work-piece. In FCW process, the edges of the work-piece to be joined are prepared with flanged edges and then placed against each other. A non-consumable friction disc tool will transverse with a constant feed rate along the edges of the work-piece, which leads to welding. The joint is formed by the action of crushing a certain amount of additional flanged material into the gap formed by the contacting material. The novelty of present work is that FCW removes the limitations of friction stir welding and Steel work pieces can be economically welded by FCW. Taguchi method of Design of Experiments (DOE) is used to find optimal process parameters of Friction Crush Welding (FCW). A L9 Orthogonal Array, Signal to Noise ratio (S/N) and Analysis of Variance are applied to analyze the effect of welding parameters (welding speed, RPM, tool profile) on the weld properties like bond strength. Grain refinement takes place in friction crush welding as is seen in friction stir welding. Friction crush welding process also has added advantage in reducing distortion and residual stresses.

Heat Transfer Simulations and Analysis of Joint Cross-Sectional Microstructure on Friction Stir Welding between Steel and Aluminium

2020 ◽  
Vol 863 ◽  
pp. 85-95
Author(s):  
Truong Minh Nhat ◽  
Truong Quoc Thanh ◽  
Tu Vinh Thong ◽  
Tran Trong Quyet ◽  
Luu Phuong Minh
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Thermal Contact ◽  
Welding Process ◽  
Welding Parameters ◽  
Thermal Imager ◽  
Sem Images ◽  
Cross Sectional ◽  
Friction Stir

This study presents conducted heat simulations and experimental jointing flat-plate of aluminum alloy 6061 and SUS 304. Temperature is simulated by the COMSOL software in three states: (1) Preheat the Friction Stir Welding (FSW) by TIG welding, (2) Thermal contact resistance between Aluminium and steel, and (3) The welding process using stiring friction is simulated. The simulations intended to predicting the temperature which is used for preheat and welding process to ensuring the required solid-state welding. The temperature is also determined and checked by a thermal imager comparing with simulation results. Besides, the results of tensile strength is carried out. The Box - Behnken method is used to identify the relationship between the welding parameters (rotation, speed and offset), temperature and tensile strength. The maximum tensile strength is 77% compared to the strength of aluminum alloy. The optimal set of parameters for the process is n = 676 rpm, v = 46 mm / min and x = 0.6 mm. The optimizing welding parameters to achieving good quality of welding process are described. SEM images to determine some properties of welding materials. This is also the basis for initial research to identify some defects in welding of two different materials (IMC thickness and interconnected pores) and the cause of these defects.

scholarly journals 3D modeling of material flow and temperature in Friction Stir Welding

2009 ◽  
Vol 14 (3) ◽  
pp. 248-256 ◽  
Author(s):  
Diego Santiago ◽  
Santiago Urquiza ◽  
Guillermo Lombera ◽  
Luis de Vedia
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Frictional Heating ◽  
Welding Process ◽  
Experimental Tests ◽  
General Purpose ◽  
Friction Stir ◽  
Welding Equipment ◽  
Reducing Costs ◽  
Visualization Techniques

The process of Friction Stir Welding (FSW) is a welding method developed by the "The Welding Institute" (TWI) of England in 1991. The welding equipment consists of a tool that rotates and progresses along the joint of two restrained sheets. The joint is produced by frictional heating which causes the softening of both components into a viscous-plastic condition and also by the resultant flow between the sheets to be joined. Numerical Modeling of the process can provide realistic prediction of the main variables of the process, reducing the number of experimental tests, thus accelerating the design processes while reducing costs and optimizing the involved technological variables. In this study the friction stir welding process is modeled using a general purpose finite element based program, reproducing the material thermal map and the corresponding mass flow. Numerical thermal results are compared against experimental thermographic maps and numerical material flow results are compared with material flow visualization techniques, with acceptable concordance.

Numerical Study of the Tool Rake Angle Effect on the Material Flow in Friction Stir Welding Process

2007 ◽  
Author(s):  
Hosein Atharifar ◽  
Radovan Kovacevic
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Numerical Study ◽  
Welding Process ◽  
Rake Angle ◽  
Heat Transfer Analysis ◽  
Tool Geometry ◽  
Friction Stir ◽  
Tool Pin ◽  
Welding Processes

Minimizing consumed energy in friction stir welding (FSW) is one of the prominent considerations in the process development. Modifications of the FSW tool geometry might be categorized as the initial attempt to achieve a minimum FSW effort. Advanced tool pin and shoulder features as well as a low-conductive backing plate, high-conductive FSW tools equipped with cooling fins, and single or multi-step welding processes are all carried out to achieve a flawless weld with reduced welding effort. The outcomes of these attempts are considerable, primarily when the tool pin traditional designs are replaced with threaded, Trifiute or Trivex geometries. Nevertheless, the problem remains as to how an inclined tool affects the material flow characteristics and the loads applied to the tool. It is experimentally proven that a positive rake angle facilitates the traverse motion of the FSW tool; however, few computational evidences were provided. In this study, numerical material flow and heat transfer analysis are carried out for the presumed tool rake angle ranging from −4° to 4°. Afterwards, the effects of the tool rake angle to the dynamic pressure distribution, strain-rates, and velocity profiles are numerically computed. Furthermore, coefficients of drag, lift, and side force and moment applied to the tool from the visco-plastic material region are computed for each of the tool rake angles. Eventually, this paper confirms that the rake angle dramatically affects the magnitude of the loads applied to the FSW tool, and the developed advanced numerical model might be used to find optimum tool rake angle for other aluminum alloys.

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