scholarly journals Effect of Pin Shape on Thermal History of Aluminum-Steel Friction Stir Welded Joint: Computational Fluid Dynamic Modeling and Validation

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7883
Author(s):  
Dmitry Olegovich Bokov ◽  
Mohammed Abed Jawad ◽  
Wanich Suksatan ◽  
Mahmoud E. Abdullah ◽  
Aleksandra Świerczyńska ◽  
...  
Keyword(s):  
Heat Generation ◽  
Fluid Dynamic ◽  
Low Carbon Steel ◽  
Flow Simulation ◽  
Total Heat ◽  
Frictional Heat ◽  
Low Carbon ◽  
Maximum Heat ◽  
Friction Stir ◽  
Simulation Results

This article studied the effects of pin angle on heat generation and temperature distribution during friction stir welding (FSW) of AA1100 aluminum alloy and St-14 low carbon steel. A validated computational fluid dynamics (CFD) model was implemented to simulate the FSW process. Scanning electron microscopy (SEM) was employed in order to investigate internal materials’ flow. Simulation results revealed that the mechanical work on the joint line increased with the pin angle and larger stir zone forms. The simulation results show that in the angled pin tool, more than 26% of the total heat is produced by the pin. Meanwhile, in other cases, the total heat produced by the pin was near 15% of the total generated heat. The thermo-mechanical cycle in the steel zone increased, and consequently, mechanical interlock between base metals increased. The simulation output demonstrated that the frictional heat generation with a tool without a pin angle is higher than an angled pin. The calculation result also shows that the maximum heat was generated on the steel side.

scholarly journals Thermo-Mechanical Simulation of Underwater Friction Stir Welding of Low Carbon Steel

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4953
Author(s):  
Shabbir Memon ◽  
Jacek Tomków ◽  
Hesamoddin Aghajani Derazkola
Keyword(s):  
Friction Stir Welding ◽  
Carbon Steel ◽  
Water Environment ◽  
Low Carbon Steel ◽  
Heat Diffusion ◽  
Frictional Heat ◽  
Low Carbon ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Simulation Results

This article investigates the flow of materials and weld formation during underwater friction stir welding (UFSW) of low carbon steel. A thermo-mechanical model is used to understand the relation between frictional heat phenomena during the welding and weld properties. To better understand the effects of the water environment, the simulation and experimental results were compared with the sample prepared by the traditional friction stir welding (FSW) method. Simulation results from surface heat diffusion indicate a smaller preheated area in front of the FSW tool declined the total generated heat in the UFSWed case compared to the FSWed sample. The simulation results revealed that the strain rate of steel in the stir zone (SZ) of the FSWed joint is higher than in the UFSWed case. The microstructure of the welded sample shows that SZ’s microstructure at the UFSWed case is more refined than the FSWed case due to the higher cooling rate of the water environment. Due to obtained results, the maximum temperatures of FSWed and UFSWed cases were 1228 °C and 1008 °C. Meanwhile, the simulation results show 1200 °C and 970 °C for conventional and underwater FSW samples, respectively. The maximum material velocity in SZ predicted 0.40 m/s and 0.32 m/s for FSW and underwater FSWed samples. The better condition in the UFSW case caused the ultimate tensile strength of welded sample to increase ~20% compared to the FSW joint.

Thermo-mechanical modelling of the Friction Stir Spot Welding process: Effect of the friction models on the heat generation mechanisms

2022 ◽  
pp. 146442072110709
Author(s):  
Nasra Hannachi ◽  
Ali Khalfallah ◽  
Carlos Leitão ◽  
Dulce Rodrigues
Keyword(s):  
Numerical Simulation ◽  
Heat Generation ◽  
Spot Welding ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Frictional Heat ◽  
Contact Conditions ◽  
Friction Stir ◽  
Friction Models ◽  
Generation Mechanisms

Friction Stir Spot Welding involves complex physical phenomena, which are very difficult to probe experimentally. In this regard, the numerical simulation may play a key role to gain insight into this complex thermo-mechanical process. It is often used to mimic specific experimental conditions to forecast outputs that may be substantial to analyse and elucidate the mechanisms behind the Friction Stir Spot Welding process. This welding technique uses frictional heat generated by a rotating tool to join materials. The heat generation mechanisms are governed by a combination of sliding and sticking contact conditions. In the numerical simulation, these contact conditions are thoroughly dependent on the used friction model. Hence, a successful prediction of the process relies on the appropriate selection of the contact model and parameters. This work aims to identify the pros and cons of different friction models in modelling combined sliding-sticking conditions. A three-dimensional coupled thermo-mechanical FE model, based on a Coupled Eulerian-Lagrangian formulation, was developed. Different friction models are adopted to simulate the Friction Stir Spot Welding of the AA6082-T6 aluminium alloy. For these friction models, the temperature evolution, the heat generation, and the plastic deformation were analysed and compared with experimental results. It was realized that numerical analysis of Friction Stir Spot Welding can be effective and reliable as long as the interfacial friction characteristics are properly modelled. This approach may be used to guide the contact modelling strategy for the simulation of the Friction Stir Spot Welding process and its derivatives.

scholarly journals Development of friction stir welding technology of low-carbon steel plates

2020 ◽  
Vol 1546 ◽  
pp. 012057
Author(s):  
I K Chenykh ◽  
E V Vasil’ev ◽  
A N Abakumov ◽  
N V Zakharova ◽  
K A Sinogina
Keyword(s):  
Friction Stir Welding ◽  
Carbon Steel ◽  
Low Carbon Steel ◽  
Steel Plates ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Technology

A Numerical and Experimental Analysis of Microstructural Aspects in AA2024-T3 Friction Stir Welding

2013 ◽  
Vol 554-557 ◽  
pp. 1022-1030 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Heat Generation ◽  
Process Parameters ◽  
Fluid Dynamic ◽  
Weld Line ◽  
Work Piece ◽  
Viscoplastic Material ◽  
Influence Of Process Parameters ◽  
Friction Stir

In recent years, remarkable interest has been focused on the Friction Stir Welding (FSW) process, by academic as well as industrial research groups. Conceptually, the FSW process is quite simple: a non-consumable rotating tool is plunged between the adjoining edges of the parts to be welded and moved along the desired weld line. Frictional and viscous heat generation increases the work piece temperature, softening the processing material and forcing it to flow around the pin. Although FSW has been effectively applied in welding of several materials, such as copper, steel, magnesium, and titanium, considerable attention is still focused on aluminum welding, in particular for transport applications. Recent literature clearly evidenced microstructural variations in the stir zone, imputable to continuous dynamic recrystallization phenomena, leading to the formation of a finer equiaxed grains. Moreover, depending on the specific alloy, thermal cycles can induce coarsening or dissolution of precipitates in the thermo-mechanically affected zone (TMAZ) and in the heat affected zone (HAZ). The influence of the aforementioned microstructural aspects on mechanical properties and formability of FSWed assemblies is also well recognized. The aim of this paper is to numerically and experimentally investigate the influence of process parameters, namely rotating speed and welding speed, on microstructural aspects in AA2024-T3 friction stir butt welds. A three-dimensional Computational Fluid Dynamic (CFD) model has been implemented to simulate the process. A viscoplastic material model, based on Wright and Sheppard modification of the constitutive model initially proposed by Sellars and Tegart has been implemented in the commercial package ANSYS CFX, considering an Eulerian framework. Tool-workpiece interaction has been modeled assuming partial sticking/sliding condition, and incorporating both frictional and viscous contributions to the heat generation. Microstructural aspects have been numerically predicted using the Zenner-Holloman parameter and experimentally measured by means of conventional metallographic techniques. Satisfactory agreement has been found between simulated and experimental results. The influence of process parameters on mechanical properties has also been highlighted.

Sign in / Sign up

Export Citation Format

Share Document