Development of a Mechanistic Model for Friction Stir Channeling

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
N. Balasubramanian ◽  
R. S. Mishra ◽  
K. Krishnamurthy
Keyword(s):  
Specific Energy ◽  
Thermal Cycle ◽  
Mechanistic Model ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Processing Conditions ◽  
Ir Camera ◽  
Plunge Depth ◽  
Friction Stir ◽  
Infra Red

A mechanistic model for the process specific energy as a function of the processing parameters during friction stir channeling (FSC) in Al6061-T6 was developed and investigated. The thermal cycle acting on the surface of the workpiece was measured using an infra red (IR) camera and the peak temperatures were studied as a function of the specific energy. The channel area is plotted against the process specific energy and is analyzed. A relationship between the processing conditions (tool rotational rate, traverse speed, and plunge depth) and the channel area is defined.

Influence of Friction Stir Processing Parameters on the Fabrication of SiC/316L Surface Composite

2010 ◽  
Vol 297-301 ◽  
pp. 221-226 ◽  
Author(s):  
R. Salekrostam ◽  
M.K. Besharati Givi ◽  
P. Asadi ◽  
P. Bahemmat
Keyword(s):  
Stainless Steel ◽  
Friction Stir Processing ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Stainless Steel 316L ◽  
Friction Stir ◽  
The Many ◽  
Welding Processes

Compared to the many fusion welding processes that are routinely used for joining stainless steel 316L, the friction stir welding (FSW) process is an emerging solid state joining process in which the material that is being welded does not melt and is being recast. The welding parameters play a major role in deciding the weld quality. In this investigation an attempt has been made to understand the influences of rotational speed and traverse speed of the tool on the microstructure of the friction stir processing zone in stainless steel 316L. Five different tool rotational speeds have been used to fabricate the joints at four different traverse speeds from this investigation which is the optimum for the tool speed and higher or lower amounts of these parameters are not useful for the process.

The Extrinsic Influence of Tool Plunge Depth on Friction Stir Welding of an Aluminum Alloy

2011 ◽  
Vol 410 ◽  
pp. 206-215 ◽  
Author(s):  
K. Kandasamy ◽  
Satish V. Kailas ◽  
Tirumalai S. Srivatsan
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Rotation Speed ◽  
Tool Material ◽  
Traverse Speed ◽  
Test Machine ◽  
Plunge Depth ◽  
Friction Stir ◽  
Scientific Approach ◽  
Tool Rotation

The axial force during friction stir welding is sensitive to plunge depth of the tool and is one of the prime factors, which exercises control over heat generation during welding. Consequently, the plunge depth for a given tool rotation speed, traverse speed, material and test machine needs to be optimized so as to get a defect-free weld. In this paper, we present and briefly discuss the results of an elaborate and enriching investigation aimed at understanding the extrinsic influence of plunge depth of the tool on weld formation in aluminium alloy 7020-T6 for a range of rotation rate and traverse speed and using two different tools. The critical need for use of a scientific approach to optimize plunge depth for a given tool material and test machine in fewer number of steps is emphasized. Key Words: Friction Stir Welding, Tool Plunge, Rotation speed, Traverse speed, Aluminium Alloy 7020

Thermal Analysis of Friction Stir Welding Process Under Different Control and Energy Parameters

2015 ◽  
Author(s):  
Dalong Yi ◽  
Hui Zhang
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Thermal Condition ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Traverse Speed ◽  
Transfer Model ◽  
Welding Condition ◽  
Plunge Depth ◽  
Friction Stir

Friction Sir Welding (FSW) process is a solid state welding technology which is widely used in manufacturing field for joints of many types of same or dissimilar materials such as aluminum alloys, magnesium alloys and steels and so on. In addition, FSW process is also a complex process associated with heat transfer, plastic deformation, grain recrystallization and material property changing phenomenon. It is commonly known that the thermal condition or the temperature distribution of space and time is important to the final welding condition. However, due to the limitation of experiment measurement and the unfinished work of numerical heat transfer model, the relationship between thermal condition and control parameters still remains a question. In this work, a new numerical model based on energy analysis and finite element method is built to calculate the thermal field of FSW process. The energy generation due to plunge depth and the converting coefficient of friction energy to heat are considered in the model. The effects of energy distribution of both sides, energy efficiency of friction, plunge depth, normal force, traverse speed and rotation speed on the temperature distribution of FSW process are investigated.

scholarly journals A New Approach to Direct Friction Stir Processing for Fabricating Surface Composites

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 638
Author(s):  
Abdulla I. Almazrouee ◽  
Khaled J. Al-Fadhalah ◽  
Saleh N. Alhajeri
Keyword(s):  
Friction Stir Processing ◽  
Composite Layer ◽  
Aluminum Matrix ◽  
Cylindrical Body ◽  
Processing Parameters ◽  
Metallographic Examination ◽  
New Approach ◽  
Plunge Depth ◽  
Friction Stir ◽  
Surface Composites

Friction stir processing (FSP) is a green fabrication technique that has been effectively adopted in various engineering applications. One of the promising advantages of FSP is its applicability in the development of surface composites. In the current work, a new approach for direct friction stir processing is considered for the surface fabrication of aluminum-based composites reinforced with micro-sized silicon carbide particles (SiC), eliminating the prolonged preprocessing stages of preparing the sample and filling the holes of grooves. The proposed design of the FSP tool consists of two parts: an inner-threaded hollow cylindrical body; and a pin-less hollow shoulder. The design is examined with respect to three important tool processing parameters: the tilt angle of the tool, the tool’s dispersing hole, and the tool’s plunge depth. The current study shows that the use of a dispersing hole with a diameter of 6 mm of and a plunge depth of 0.6 mm, in combination with a tilting angle of 7°, results in sufficient mixing of the enforcement particles in the aluminum matrix, while still maintaining uniformity in the thickness of the composite layer. Metallographic examination of the Al/SiC surface composite demonstrates a uniform distribution of the Si particles and excellent adherence to the aluminum substrate. Microhardness measurements also show a remarkable increase, from 38.5 Hv at the base metal to a maximum value of 78 Hv in the processed matrix in the surface composites layer. The effect of the processing parameters was also studied, and its consequences with respect to the surface composites are discussed.

scholarly journals Numerical and experimental investigation of defects formation during friction stir processing on AZ91

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Hoda Agha Amini Fashami ◽  
Nasrollah Bani Mostafa Arab ◽  
Mohammad Hoseinpour Gollo ◽  
Bahram Nami
Keyword(s):  
Friction Stir Processing ◽  
High Speed ◽  
Large Scale ◽  
Melting Zone ◽  
Traverse Speed ◽  
Experimental Results ◽  
Peak Temperature ◽  
Speed Ratio ◽  
Processing Conditions ◽  
Friction Stir

Abstract The heat generated during friction stir processing greatly affects defects formation in the processed zone of workpieces. In this paper, numerical modeling of this process is performed to determine the influence of tool rotational and traverse speeds and hence their ratio on the thermal distribution attained during the process. The aim is to produce defect-free processed samples by selecting adequate tool speeds. The mechanisms of defects formation depending on the peak temperature are also investigated. Experiments to verify the simulation results were conducted with the same process parameters. Several traverse speeds of 20, 40, 60, and 80 mm/min and rotational speeds of 700, 1000, 1200, and 2000 rpm were used during modeling and conducting the experiments. From the numerical and experimental results, it was found that; the high-speed processing conditions (low-generated heat) can produce defects such as tunnels and grooves, and the low-speed processing conditions (high-generated heat) can cause defects such as flashes. The experimental results show that during friction stir processing with the rotational speed of 1200 rpm and the traverse speed of 60 mm/min (speed ratio of 20), no macro defects in the processed zone were observed. According to the numerical results, the peak temperature during friction stir processing with these speeds was 475 °C. At this temperature, the material softened, the structure finely equiaxed and no large scale melting zone appeared in the processed zone. The developed model can be useful to investigate the occurrence of defects associated with different tool rotational and traverse speeds. Graphic abstract

Enabling Automation of Friction Stir Welding: The Modulation of Weld Seam Input Energy by Traverse Speed Force Control

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
William R. Longhurst ◽  
Alvin M. Strauss ◽  
George E. Cook
Keyword(s):  
Standard Deviation ◽  
Axial Force ◽  
Pid Control ◽  
Force Control ◽  
Weld Seam ◽  
Traverse Speed ◽  
Work Piece ◽  
Input Energy ◽  
Plunge Depth ◽  
Friction Stir

Friction stir welding (FSW) joins materials by plunging a rotating tool into the work piece. The tool consists of a shoulder and a pin that plastically deforms the parent materials and then forges them together under the applied pressure. To create the pressure needed for forging, a rather large axial force must be maintained on the tool. Maintaining this axial force is challenging for robots due to their limited load capacity and compliant nature. To address this problem, force control has been used, and historically, the force has been controlled by adjusting the plunge depth of the tool into the work piece. This paper develops the use of tool traverse speed as the controlling variable instead of plunge depth. To perform this investigation, a FSW force controller was designed and implemented on a retrofitted Milwaukee Model K milling machine. The closed loop proportional, integral plus derivative (PID) control architecture was tuned using the Ziegler–Nichols method. Results show that the control of axial force via traverse speed is feasible and predictable. The resulting system is more robust and stable when compared with a force controller that uses plunge depth as the controlling variable. A standard deviation of 41.5 N was obtained. This variation is much less when compared with a standard deviation of 129.4 N obtained when using plunge depth. Using various combinations of PID control, the system’s response to step inputs was analyzed. From this analysis, a feed forward transfer function was modeled that describes the machinery and welding environment. From these results, a technique is presented regarding weld seam input energy modulation as a by product of force control via traverse speed. A relative indication of thermal energy in the welding environment is obtained with the feedback of axial force. It is hypothesized that, while under force control, the controller modulates weld seam input energy according to the control signal. The result is constant thermomechanical conditions in the welding environment. It is concluded that the key enablers for force control are the unidirectional behavior and load dynamics of the traverse motor. Larger bandwidths and more stable weld conditions emerge when using traverse speed instead of plunge depth to control the force. Force control of FSW via traverse speed has importance in creating efficient automatic manufacturing operations. The intelligence of the controller naturally selects the most efficient traverse speed.

scholarly journals Effects of the Processing Parameters of Friction Stir Processing on the Microstructure, Hardness and Tribological Properties of SnSbCu Bearing Alloy

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5826
Author(s):  
Beata Leszczyńska-Madej ◽  
Marcin Madej ◽  
Joanna Hrabia-Wiśnios ◽  
Aleksandra Węglowska
Keyword(s):  
Tribological Properties ◽  
Friction Stir Processing ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Friction Stir ◽  
Modification Process ◽  
Hardness Tests ◽  
Before And After ◽  
Bearing Alloy ◽  
The Impact

In the study, the friction stir processing (FSP) method was used to modify the surface layer of a tin-based bearing alloy. The modification was aimed at extending the service life of bearings by improving their tribological properties. The results of investigations of the microstructure, hardness and tribological properties of the SnSbCu bearing alloy after FSP using various rotational speeds of the tool—280, 355, 450 and 560 RPM—and the constant traverse speed of 355 mm/min are presented. Particular attention was paid to the possibility of changing the morphology of the precipitates present in the alloy, and to the impact of this parameter on improvement of the tribological properties. The research carried out in this paper covered investigations of the microstructure using light and scanning electron microscopy (SEM) along with analysis of the chemical composition in micro-areas and Brinell hardness tests. Additionally, the sizes of the SnSb and CuSn precipitates present in the microstructure before and after the modification process were determined, as were the tribological properties under technically dry friction conditions and lubrication with TU 32 oil. It was proven that using friction stir processing favors refinement of the microstructure and improves the tribological properties of the analyzed alloy.

Microstructural and Mechanical Characterization of Multipass Friction Stir Processed Al-Mg Alloy

2014 ◽  
Vol 902 ◽  
pp. 18-23
Author(s):  
S. Pradeep ◽  
Vivek Pancholi
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characterization ◽  
Rotation Speed ◽  
Bulk Material ◽  
Processing Condition ◽  
Superplastic Forming ◽  
Traverse Speed ◽  
Processing Conditions ◽  
Friction Stir

In the present investigation friction stir processing (FSP) is carried out using multipass FSP on a 5086 aluminum alloy to modify microstructure and mechanical properties. Two processing conditions P1 and P2 were used, P1 is carried out at constant rotation speed of 1025 rpm and at a traverse speed of 50 mm/min, P2 is carried out at constant rotation speed of 720 rpm and at a traverse speed of 155 mm/min. Inhomogeneous microstructural distribution was observed across the processed zone. EBSD analysis has been done to evaluate the microstructure. Overlapping passes is showing same grain size in the FSPed material. Material processed using P2 processing condition is showing maximum superplastic ductility. The bulk material produced due to multipass FSP seems to be good for superplastic forming applications.

Study of thermal cycle, mechanical, and metallurgical properties of friction stir welded aviation grade aluminum alloy

2018 ◽  
Vol 233 (11) ◽  
pp. 4202-4213 ◽  
Author(s):  
Shubham Verma ◽  
Meenu Gupta ◽  
Joy Prakash Misra
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Ultimate Tensile Strength ◽  
Tilt Angle ◽  
Thermal Cycle ◽  
Dwell Time ◽  
Traverse Speed ◽  
Energy Beam ◽  
Friction Stir

This research work presents the study of thermal cycle during friction stir welding of aviation grade aluminum alloy. In addition, mechanical and metallurgical properties of friction stir welded joints are conceptually discussed. Experimentation has been conducted in two stages. Stage I experiments has been conducted as per one-factor-at-a-time approach with varying tilt angle and dwell time. It was concluded that maximum ultimate tensile strength is obtained at 2° tilt angle and 30 s dwell time by one-factor-at-a-time approach. On the basis of stage I results, full-factorial design is used for conducting main experiments by fixing the tilt angle and dwell time. Stage II has been attempted to optimize the most influencing friction stir welding parameters: rotational speed and traverse speed. It is observed that rotational speed is predominant factors for ultimate tensile strength and traverse speed for microhardness. In addition, eight thermocouples (L-shaped k type), four on the advancing side and four on the retreating side, are placed at equal distance from the centerline for measuring the temperature during the process. The optical microscope and energy beam scattered diffraction analysis have been carried out for scrutinizing the macrostructure and microstructure of friction stir welded joints. It is evident from energy beam scattered diffraction analysis that the grain size of nugget zone decreases as compared to base metal.

The Effect of Process Parameters on the Friction Stir Processed AS7U3G Aluminium Alloy

2014 ◽  
Vol 592-594 ◽  
pp. 776-780
Author(s):  
L. John Baruch ◽  
R. Raju ◽  
V. Balasubramanian ◽  
I. Dinaharan
Keyword(s):  
Corrosion Resistance ◽  
Rotational Speed ◽  
Material Flow ◽  
Flow Behavior ◽  
Traverse Speed ◽  
Processing Parameters ◽  
Tool Rotational Speed ◽  
Flow Process ◽  
Friction Stir ◽  
State Process

Friction stir processing (FSP) is a solid-state process leading to very significant microstructural modifications. Despite the large number of studies, most of the work that has been done in the FSP field focuses on microstructural evolution, tensile properties, hardness, fatigue strength, corrosion resistance etc. However there is not much information available on correlation of FSP parameters with evolution of defect free processed zone. In order to produce a defect free processed zone, selecting the best processing parameters is very important. In this investigation, the effect of two main FSP parameters (such as tool rotational speed which was kept constant and tool transverse speed which was varied) on the formation/ evolution of defect free processed zone was studied. It is found that at a tool rotational speed 600 rpm and a traverse speed of 12 mm/min the processed zone is defect free. Numerous investigations have been conducted to understand material flow behavior during FSW/FSP. However, the flow process of material during FSW/FSP is still not well-understood, and different explanations have been proposed. In this investigation an attempt has been made to understand the flow of material during FSP and it is reported.

Sign in / Sign up

Export Citation Format

Share Document