Influence of tool thread pitch on material flow and thermal process in friction stir welding

Abstract Friction stir welding (FSW) tool pin, as a critical component of FSW tool, plays an important role in determining the final joint properties by affecting the heat generation, plastic material flow, welding loads and so on. However, the influence of tool pin on heat and mass transfer in FSW are not elucidated. In the present study, a validated model was adopted to quantitatively analyze the effects of pin size and taper angle on the thermal process and plastic material flow in FSW. It reveals that the torque and transverse force imposed on the pin are increased with the increase of the pin diameters (including its root diameter, its tip diameter and its size in condition of constant taper angle), while the total tool torque various a little for the tool pin diameter considered in this study. When the pin diameters increase, the viscosity of the materials near the pin is decreased, while the temperature as well as the flow velocity is increased. More plastic material near the tool could rotate around the tool with an increase of the pin diameter. The TMAZ boundary is enlarged with larger pin diameters in FSW. Particularly, the shear layer thickness of the same horizontal plane in the range of 1 mm < z < 5 mm is significantly enlarged with an increase of pin root diameters. However, the shear layer thickness of the same horizontal plane in the region of z < 5 mm is increased when using a larger pin tip diameter. In addition, maximum width of TMAZ boundary at the top surface of workpiece was not affected by pin diameters. The model is validated by experimental results. It lays solid foundation for optimizing the tool pin size and taper angle in FSW.

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The effect of tool pin size and taper angle on the thermal process and plastic material flow in friction stir welding

The International Journal of Advanced Manufacturing Technology ◽

10.1007/s00170-021-07650-x ◽

2021 ◽

Author(s):

Jie Chen ◽

Lei Shi ◽

Chuansong Wu ◽

Yuanning Jiang

Keyword(s):

Friction Stir Welding ◽

Material Flow ◽

Thermal Process ◽

Plastic Material ◽

Taper Angle ◽

Friction Stir ◽

Tool Pin

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Thermo-Mechanical Modelling of Friction Stir Welding Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.1155 ◽

2013 ◽

Vol 774-776 ◽

pp. 1155-1159 ◽

Cited By ~ 2

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.

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Grain Structure Formation Ahead of Tool during Friction Stir Welding of AZ31 Magnesium Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.160.313 ◽

2010 ◽

Vol 160 ◽

pp. 313-318 ◽

Cited By ~ 4

Author(s):

Uceu Suhuddin ◽

Sergey Mironov ◽

H. Takahashi ◽

Yutaka S. Sato ◽

Hiroyuki Kokawa ◽

...

Keyword(s):

Friction Stir Welding ◽

Magnesium Alloy ◽

Structure Formation ◽

Material Flow ◽

Boundary Migration ◽

Deformation Mode ◽

Grain Structure ◽

Az31 Magnesium Alloy ◽

Structure Evolution ◽

Friction Stir

The “stop-action” technique was employed to study grain structure evolution during friction-stir welding of AZ31 magnesium alloy. The grain structure formation was found to be mainly governed by the combination of the continuous and discontinuous recrystallization but also involved geometric effect of strain and local grain boundary migration. Orientation measurements showed that the deformation mode was very close to the simple shear associated with the rotating pin and material flow arose mainly from basal slip.

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Influence of Tool Geometry and Contact Condition on Friction Stir Welding of Al-Cu Laminated Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.856.16 ◽

2013 ◽

Vol 856 ◽

pp. 16-21

Author(s):

R. Beygi ◽

Mohsen Kazeminezhad ◽

A.H. Kokabi ◽

S. Mohammad Javad Alvani ◽

D. Verdera ◽

...

Keyword(s):

Friction Stir Welding ◽

Material Flow ◽

Laminated Composites ◽

Flow Behavior ◽

Tool Geometry ◽

Contact Conditions ◽

Friction Stir ◽

Tool Geometries ◽

Welding Procedure ◽

Sem Analyses

In this study friction stir welding of Al-Cu laminated composites were carried out by two different tool geometries. Welding procedure was carried out from both sides of Al and Cu. Analyzing cross section of welds showed that different contact conditions between shoulder and material, offers different material flow behavior which is dependent on the tool geometry. SEM analyses showed that mixing of materials in nugget region is more pronounced in the advancing side. Also XRD results indicated that welding from Cu side, leads to intermetallic formation in mixed regions.

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

Volume 11: Heat Transfer and Thermal Engineering ◽

10.1115/imece2020-23193 ◽

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.

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