Effects of Heat Transfer on Microhardness and Microstructure of Friction Stir Welded AA 6061 Aluminum Alloy

2015 ◽  
Vol 21 ◽  
pp. 102-109 ◽  
Author(s):  
S.T. Selvamani ◽  
M. Vigneshwar ◽  
S. Divagar
Keyword(s):  
Heat Transfer ◽  
Aluminum Alloy ◽  
Research Work ◽  
Three Dimensional ◽  
Element Model ◽  
Heat Transfer Process ◽  
Butt Welding ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Tool Pin

In this research work, the effects of heat transfer on microhardness, microstructures of friction stir welded AA 6061-T6 Aluminum alloy butt joints advancing side and retreating side are analyzed. A three dimensional finite element model is developed to study the thermal history in the butt welding of AA 6061 aluminum alloy using ANSYS package. Solid 70 elements are used to develop the model and a moving co-ordinate has been introduced to model the three-dimensional heat transfer process because it reduces the difficulty of modeling the moving tool. In this model, the main parameter considered is the heat input from the tool shoulder and tool pin. As a result, the temperature distributions of the weld at a welding speed of 1.25mm/sec were obtained.

Numerical and experimental study of the heat transfer process in friction stir welding

2003 ◽  
Vol 217 (1) ◽  
pp. 73-85 ◽  
Author(s):  
M Song ◽  
R Kovacevic
Keyword(s):  
Heat Transfer ◽  
Friction Stir Welding ◽  
Transfer Process ◽  
Three Dimensional ◽  
Heat Transfer Process ◽  
Frictional Heat ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin ◽  
Good Agreement

A mathematical model to describe the detailed three-dimensional transient heat transfer process in friction stir welding (FSW) is presented. This work is both theoretical and experimental. An explicit central differential scheme is used in solving the control equations, the heat transfer phenomena during the tool penetrating, the welding and the tool-removing periods that are studied dynamically. The heat input from the tool shoulder is modelled as a frictional heat and the heat from the tool pin is modelled as a uniform volumetric heat generated by the plastic deformation near the pin. The temperature variation during the welding is also measured to validate the calculated results. The calculated results are in good agreement with the experimental data.

Numerical simulation of friction stir butt-welding of 6061 aluminum alloy

2018 ◽  
Vol 28 (6) ◽  
pp. 1216-1225 ◽  
Author(s):  
Peng-cheng ZHAO ◽  
Yi-fu SHEN ◽  
Guo-qiang HUANG ◽  
Qi-xian ZHENG
Keyword(s):  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Butt Welding ◽  
6061 Aluminum Alloy ◽  
Friction Stir

Predicting Residual Stresses in Friction Stir Welding of Aluminum Alloy 6061 Using an Integrated Multiphysics Model

2013 ◽  
Vol 768-769 ◽  
pp. 682-689 ◽  
Author(s):  
Mohamadreza Nourani ◽  
Abbas S. Milani ◽  
Spiro Yannacopoulos ◽  
Claire Yu Yan
Keyword(s):  
Heat Transfer ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Residual Stresses ◽  
Solid Mechanics ◽  
Element Model ◽  
Flow Mode ◽  
Friction Stir ◽  
Strain And Strain Rate ◽  
Thermal Expansion Effect

Experimental results in the literature show that there are two flow areas of material during the friction stir welding (FSW) process [1]; namely the “pin-driven flow” and the “shoulder-driven flow”. These areas should completely join together to create a weld with no defect. First, in order to numerically predict the local distribution of flow stress around the pin as well as the temperature, strain, and strain rate fields during FSW, a two-dimensional steady-state Eulerian multiphysics finite element model has been employed in this work for aluminum alloy 6061using the COMSOL software. In this model, the non-Newtonian flow mode of computational fluid dynamics (CFD) module, general heat transfer mode of the heat transfer module, and the plain stress mode of the structural mechanics module of the software have been coupled. Slip/stick condition between the tool and workpiece, frictional and deformation heat sources, the convectional heat transfer in the workpiece, the solid mechanics-based viscosity definition, the temperature-dependent physical properties and the Zener-Hollomon- based thermo-visco-plastic mechanical properties with a cut-off temperature of 582oC were considered. Next, the thermal history during the process predicted by the model was used as input for an elasto-visco-plastic analysis to estimate the local residual stresses distribution due to the workpiece thermal expansion effect. Finally, the predicted longitudinal and transverse residual stresses were verified by comparing to experimental data.

Modified Friction Stir Channeling: A Novel Technique for Fabrication of Friction Stir Channel

2013 ◽  
Vol 302 ◽  
pp. 365-370 ◽  
Author(s):  
Arash Rashidi ◽  
Amir Mostafapour ◽  
Salar Salahi ◽  
Vahid Rezazadeh
Keyword(s):  
Aluminum Alloy ◽  
Heat Exchanger ◽  
Work Piece ◽  
Simple Method ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Novel Technique ◽  
Regular Shape ◽  
Tool Profile ◽  
Tool Pin

Friction stir channeling (FSC) is a simple method for fabrication of a continuous, integral channel in a monolithic plate, which is carried out in a single pass. The fabricated channels can be applied in heat exchanger industry. In this study, a novel technique was introduced to produce channels in 6061 aluminum alloy which is named as Modified Friction Stir Channeling (MFSC). This technique is derived from Friction stir processing. In this technique, the tool profile and position of tool pin against work piece were designed differently from FSC process. Channels were fabricated with a very regular shape such as rectangular. Comparison between MFSC and FSC showed that fabricated channels, using MFSC process, had better properties relative to fabricated channels by FSC.

Effect of tool pin profile on distribution of reinforcement particles during friction stir processing of B4C/aluminum composites

2016 ◽  
Vol 232 (8) ◽  
pp. 637-651 ◽  
Author(s):  
Mohammad Hasan Shojaeefard ◽  
Mostafa Akbari ◽  
Abolfazl Khalkhali ◽  
Parviz Asadi
Keyword(s):  
Wear Resistance ◽  
Boron Carbide ◽  
Friction Stir Processing ◽  
Cast Alloy ◽  
Three Dimensional ◽  
Element Model ◽  
Aluminum Composites ◽  
Friction Stir ◽  
Three Dimensional Finite Element ◽  
Tool Pin

Boron carbide /aluminum composites have been produced on an aluminum–silicon cast alloy using friction stir processing. Effect of pin profile on the distribution of boron carbide in the stir zone of the friction stir processed specimens was investigated experimentally and numerically. The material flow generated by the threaded and circular tool pin profiles, being the main reason for the distribution of particles in the metal matrix, was numerically modeled using a thermomechanically coupled three-dimensional finite element model. Numerical and experimental results show that threaded pin profile produces a more uniform distribution of B4Cp than other pin profiles. Hardness tests were performed in order to investigate mechanical properties of the composites. Wear resistance of the composite was evaluated and obtained results showed that the hardness and wear resistance of the composite significantly improved.

Numerical Study on the Effect of Inner Tube Position on Heat Transfer Process in Self-Recuperative Radiant Tube

2011 ◽  
Vol 228-229 ◽  
pp. 676-680 ◽  
Author(s):  
Ye Tian ◽  
Xun Liang Liu ◽  
Zhi Wen
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Numerical Study ◽  
Flame Temperature ◽  
Three Dimensional ◽  
Mathematic Model ◽  
Heat Transfer Process ◽  
Bulk Temperature ◽  
Radiant Tube ◽  
Peak Value

A three-dimensional mathematic model is developed for a 100kw single-end recuperative radiant tube and the simulation is performed with the CFD software FLUENT. Also it is used to investigate the effect of distance between combustion chamber exit and inner tube on heat transfer process. The results suggest that the peak value of combustion flame temperature drops along with the increasing of distance, which leads to low NOX discharging. Also radiant tube surface bulk temperature decreases, which causes radiant tube heating performance losses.

scholarly journals Increasing of the Mechanical Properties of Friction Stir Welded Joints of 6061 Aluminum Alloy by Introducing Alumina Particles

2017 ◽  
Vol 17 (2) ◽  
pp. 29-40 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-Jarrah ◽  
M. Ibrahim
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Welded Joints ◽  
Volume Fraction ◽  
Welding Process ◽  
Welding Zone ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Alumina Particles ◽  
Welding Line

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.

Analytical Modeling of Temperature Distribution in Interposer-Based Microelectronic Systems

2013 ◽  
Author(s):  
Leila Choobineh ◽  
Dereje Agonafer ◽  
Ankur Jain
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Analytical Modeling ◽  
Three Dimensional ◽  
Heat Transfer Process ◽  
Thermal Design ◽  
Research Attention ◽  
On Chip

Heterogeneous integration in microelectronic systems using interposer technology has attracted significant research attention in the past few years. Interposer technology is based on stacking of several heterogeneous chips on a common carrier substrate, also referred to as the interposer. Compared to other technologies such as System-on-Chip (SoC) or System-in-Package (SiP), interposer-based integration offers several technological advantages. However, the thermal management of an interposer-based system is not well understood. The presence of multiple heat sources in various die and the interposer itself needs to be accounted for in any effective thermal model. While a finite-element based simulation may provide a reasonable temperature prediction tool, an analytical solution is highly desirable for understanding the fundamentals of the heat transfer process in interposers. In this paper, we describe our recent work on analytical modeling of heat transfer in interposer-based microelectronic systems. The basic governing energy conservation equations are solved to derive analytical expressions for the temperature distribution in an interposer-based microelectronic system. These solutions are combined with an iterative approach to provide the three-dimensional temperature field in an interposer. Results are in excellent agreement with finite-element solutions. The analytical model is utilized to study the effect of various parameters on the temperature field in an interposer system. Results from this work may be helpful in the thermal design of microelectronic systems containing interposers.

Reduced Rough-Surface Parametrization for Use With the Discrete-Element Model

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Stephen T. McClain ◽  
Jason M. Brown
Keyword(s):  
Heat Transfer ◽  
Rough Surface ◽  
Surface Characterization ◽  
Rough Surfaces ◽  
Roughness Element ◽  
Three Dimensional ◽  
Element Model ◽  
Discrete Element ◽  
Diameter Distribution ◽  
Discrete Element Model

The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element diameter distribution as a function of height to predict the drag and heat transfer of flow over a randomly rough surface. The requirement for a roughness-element diameter distribution at each height from the reference elevation has hindered the usefulness of the discrete-element model and inhibited its incorporation into a computational fluid dynamics (CFD) solver. To incorporate the discrete-element model into a CFD solver and to enable the discrete-element model to become a more useful engineering tool, the randomly rough surface characterization must be simplified. Methods for determining characteristic diameters for drag and heat transfer using complete three-dimensional surface measurements are presented. Drag and heat transfer predictions made using the model simplifications are compared to predictions made using the complete surface characterization and to experimental measurements for two randomly rough surfaces. Methods to use statistical surface information, as opposed to the complete three-dimensional surface measurements, to evaluate the characteristic dimensions of the roughness are also explored.

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