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Diogo Mariano Neto Pedro Neto 《The International Journal of Advanced Manufacturing Technology》2013,65(1-4):115-126
This survey presents a literature review on friction stir welding (FSW) modeling with a special focus on the heat generation due to the contact conditions between the FSW tool and the workpiece. The physical process is described and the main process parameters that are relevant to its modeling are highlighted. The contact conditions (sliding/sticking) are presented as well as an analytical model that allows estimating the associated heat generation. The modeling of the FSW process requires the knowledge of the heat loss mechanisms, which are discussed mainly considering the more commonly adopted formulations. Different approaches that have been used to investigate the material flow are presented and their advantages/drawbacks are discussed. A reliable FSW process modeling depends on the fine tuning of some process and material parameters. Usually, these parameters are achieved with base on experimental data. The numerical modeling of the FSW process can help to achieve such parameters with less effort and with economic advantages. 相似文献
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Kadir Gök Mustafa Aydin 《The International Journal of Advanced Manufacturing Technology》2013,68(1-4):775-780
The aim of this study is to investigate the process of friction stir welding (FSW) by using finite element method (FEM). Currently, the materials that are difficult to be joined with conventional fusion methods can now be easily joined with the method of friction stir welding. In this paper, the welding capability of many different materials with this method has been investigated by using analytical and numeric methods. In this study, a finite element (FE) model was developed for welding process with friction stir welding of AZ31 magnesium alloy. This model was performed by the software of DEFORM 3D finite element in 960, 1,964, and 2,880 rpm rotational speeds and in 10 and 20 mm?min?1 transverse speeds. The temperature values taken from experiments and the temperature values with FEM are compared, and according to these results, it can be stated that the FE model gives reasonable results with experimental results based on temperatures values. Hence, the FE model can be used to predict other parameters of FSW process in future studies. 相似文献
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Vicharapu B. Liu H. Fujii H. Narasaki K. Ma N. De A. 《The International Journal of Advanced Manufacturing Technology》2020,106(5):1573-1586
The International Journal of Advanced Manufacturing Technology - Stationary shoulder friction stir welding (SSFSW) is a new variant of the conventional FSW with rotation of only the tool probe to... 相似文献
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Z. Zhang H. W. Zhang 《The International Journal of Advanced Manufacturing Technology》2007,35(1-2):101-100
This paper presents the 3D material flows and mechanical features under different process parameters by using the finite element
method based on solid mechanics. Experimental results are also given to study the effect of process parameters on joining
properties of the friction stir welds. Numerical results indicate that the tangent flow constitutes the major part in the
material flow. The shoulder can accelerate the material flow on the top half of the friction stir weld. The distribution of
the equivalent plastic strain can correlate well with the microstructure zones. Increasing the angular velocity of the pin,
the material in the nugget zone can be more fully mixed, which improves the joining quality of the two welding plates. The
increase of speeds, including the rotational speed and the translational speed, can both accelerate the material flow, especially
in front of the pin on the retreating side where the fastest material flow occurs. The contact pressure on the pin-plate interface
is decreased with the increase of the angular velocity.
An erratum to this article can be found at 相似文献
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《Measurement》2014
This investigation presents the feasibility of ultrasonic temperature measurement of friction stir spot welding (FSSW). FSSW is an automated solid state joining process. Thermal profiles of the weld zone are crucial for implementing informed process changes to improve weld quality. Ultrasonics present a novel and non-invasive method of monitoring changes in temperature.Ultrasonic time of flight (TOF) measurement method is used to calculate the temperature of Al 6061 as it is heated. Comparisons of the ultrasonic temperature calculations with thermocouple readings confirm the accuracy of the ultrasonic system. The ultrasonic signal is then recorded during spot welding and processed. The results show that ultrasonic technology is a feasible method of monitoring the heating and cooling profiles of the weld zone during welding. The paper also discusses challenges presented by the system as well as recommendations for its future implementation in the friction stir welding manufacturing industry. 相似文献
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Kim Young Gon Kim Ji Sun Kim In Ju 《Journal of Mechanical Science and Technology》2014,28(12):5143-5148
Journal of Mechanical Science and Technology - In the automotive industry, vehicle weight reduction techniques have been actively studied to improve the rate of fuel consumption and to cope with... 相似文献
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Edward G. Cole Axel Fehrenbacher Edward F. Shultz Christopher B. Smith Nicola J. Ferrier Michael R. Zinn Frank E. Pfefferkorn 《The International Journal of Advanced Manufacturing Technology》2012,63(5-8):583-593
This paper explores common process variations encountered in friction stir welding (FSW) and the limits to which acceptable joint strength is maintained while welding with a robotic FSW system. Part fit-up and mating variations are common in manufacturing, yet the limits to which a friction stir welding process can weld without major process adjustment are unclear. The effects on joint strength and mechanical properties of several of the most common mating variations (i.e., faying surface gap, misalignment, mismatch, etc.) are experimentally determined as individual effects as well as among common welding parameters. Experimental results on 5-mm-thick aluminum alloy 5083-H111 show that ultimate tensile strength, yield strength, and elongation begin to decrease from nominal weld conditions when either the tool offset distance from weld centerline or gap in abutted plates exceeds 25% of the average pin diameter (6?mm). In addition, vertical plate mismatch and lack of penetration can be tolerated up to 2.5% and 10%, respectively, before adverse effects on mechanical properties are observed. The work also indicates that of all the mating variations tested in this study, tool misalignment, followed by travel angle, has the most significant effect on the measured joint strength. Process stability testing has shown that the FSW process is able to endure part fit-up and mating variations within a defined tolerance, giving the practitioner an awareness of how well stock workpiece tolerances must be controlled before joint strength is adversely effected. 相似文献
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William R. Longhurst Alvin M. Strauss George E. Cook Paul A. Fleming 《The International Journal of Advanced Manufacturing Technology》2010,51(9-12):905-913
Friction stir welding (FSW) is a solid-state welding process that utilizes a rotating tool to plastically deform and forge together the parent materials of a workpiece. The process involves plunging the rotating tool that consists of a shoulder and a pin into the workpiece and then traversing it along the intended weld seam. The welding process requires a large axial force to be maintained on the tool. Axial force control has been used in robotic FSW processes to compensate for the compliant nature of robots. Without force control, welding flaws would continuously emerge as the robot repositioned its linkages to traverse the tool along the intended weld seam. Insufficient plunge depth would result and cause the welding flaws as the robot’s linkages yielded from the resulting force in the welding environment. The research present in this paper investigates the use of torque instead of force to control the FSW process. To perform this research, a torque controller was implemented on a retrofitted Milwaukee Model K milling machine. The closed loop proportional, integral plus derivative control architecture was tuned using the Ziegler–Nichols method. Welding experiments were conducted by butt welding 0.25 in. (6.35 mm)?×?1.5 in. (38.1 mm)?×?8 in. (203.2 mm) samples of aluminum 6061 with a 0.25 in. (6.35 mm) threaded tool. The results indicate that controlling torque produces an acceptable weld process that adapts to the changing surface conditions of the workpiece. For this experiment, the torque was able to be controlled with standard deviation of 0.231 N-m. In addition, the torque controller was able to adjust the tool’s plunge depth in reaction to 1 mm step and ramp disturbances in the workpiece’s surface. It is shown that torque control is equivalent to weld power control and causes a uniform amount of energy per unit length to be deposited along the weld seam. It is concluded that the feedback signal of torque provides a better indicator of tool depth into the workpiece than axial force. Torque is more sensitive to tool depth than axial force. Thus, it is concluded that torque control is better suited for keeping a friction stir welding tool properly engaged with the workpiece for application to robotics, automation, and manufacturing. 相似文献
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Prakash Prashant Anand Ravi Shankar Jha Sanjay Kumar 《Journal of Mechanical Science and Technology》2020,34(1):279-287
Journal of Mechanical Science and Technology - This article investigates the effect of tool pin profile on weld zone shape using computational fluid dynamics techniques in friction stir welding... 相似文献
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Z. Zhang H. W. Zhang 《The International Journal of Advanced Manufacturing Technology》2014,72(9-12):1647-1653
A new Eulerian model is established based on solid mechanics. With comparisons to the experimental data and the ALE model, the current model is validated. The power and the heat generations from pin side surface, pin tip surface, and shoulder contact surface in different rotating speeds are studied. Results indicate that the ratio of the heat input powers from the pin and the shoulder keeps constant in different rotating speeds. The velocity of the material flow around the welding tool and the slipping velocity are both increased with the increase of the rotating speed. The increase of the slipping velocity is the main reason for the increase of the heat input with the increase of the rotating speed. The torque from the shoulder contact surface is the major part of the total torque. The contribution to the total torque from the pin tip surface is the smallest. 相似文献
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Kanwer S. Arora Sunil Pandey Michael Schaper Rajneesh Kumar 《The International Journal of Advanced Manufacturing Technology》2010,50(9-12):941-952
In this work, successful friction stir welding of aluminum alloy 2219 using an adapted milling machine is reported. The downward or forging force was found to be dependent upon shoulder diameter and rotational speed whereas longitudinal or welding force on welding speed and pin diameter. Tensile strength of welds was significantly affected by welding speed and shoulder diameter whereas welding speed strongly affected percentage elongation. Metallographic studies revealed fine equiaxed grains in weld nugget and microstructural changes in thermo-mechanically affected zone were found to be the result of combined and interactive influences of frictional heat and deformation. A maximum joining efficiency of 75% was obtained for welds with reasonably good percentage elongation. TEM studies indicated coarsening and/or dissolving of precipitates in nugget. For the gas metal arc weld, SEM investigations revealed segregation of copper at grain boundaries in partially melted zone. 相似文献
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P. Janaki Ramulu R. Ganesh Narayanan Satish V. Kailas Jayachandra Reddy 《The International Journal of Advanced Manufacturing Technology》2013,65(9-12):1515-1528
Welding parameters like welding speed, rotation speed, plunge depth, shoulder diameter etc., influence the weld zone properties, microstructure of friction stir welds, and forming behavior of welded sheets in a synergistic fashion. The main aims of the present work are to (1) analyze the effect of welding speed, rotation speed, plunge depth, and shoulder diameter on the formation of internal defects during friction stir welding (FSW), (2) study the effect on axial force and torque during welding, (c) optimize the welding parameters for producing internal defect-free welds, and (d) propose and validate a simple criterion to identify defect-free weld formation. The base material used for FSW throughout the work is Al 6061T6 having a thickness value of 2.1 mm. Only butt welding of sheets is aimed in the present work. It is observed from the present analysis that higher welding speed, higher rotation speed, and higher plunge depth are preferred for producing a weld without internal defects. All the shoulder diameters used for FSW in the present work produced defect-free welds. The axial force and torque are not constant and a large variation is seen with respect to FSW parameters that produced defective welds. In the case of defect-free weld formation, the axial force and torque are relatively constant. A simple criterion, (?τ/?p)defective?>?(?τ/?p)defect free and (?F/?p)defective?>?(?F/?p)defect free, is proposed with this observation for identifying the onset of defect-free weld formation. Here F is axial force, τ is torque, and p is welding speed or tool rotation speed or plunge depth. The same criterion is validated with respect to Al 5xxx base material. Even in this case, the axial force and torque remained constant while producing defect-free welds. 相似文献
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H. T. Hsieh J. L. Chen 《The International Journal of Advanced Manufacturing Technology》2010,46(9-12):1085-1102
Welding is an extremely important joining method in the manufacturing process. For the last few years, the friction stir welding (FSW) method has significantly increased the quality of a weld. However, FSW has a slightly short research and application progress. The related applied experiences are not prevalent. Therefore, FSW has a lack of reference information on related welding applied design, such as fixture, joining, and integrated design. This article intends to combine innovative design methods in the application of FSW design. Additionally, this article establishes the applied design mode of FSW through case analysis to assist engineers or design personnel who are not familiar with the FSW process. This will help to decrease trial and error or failure risks in the welding process of fixture design. Encountered welding difficulties are thus solved after being guided by the theory of inventive problem solving (TRIZ) design method. By combining traditional TRIZ design methods, this article also refers to other TRIZ methods proposed by some scholars because work will often encounter various engineering challenges. This article hopes to provide welding design personnel with innovative design ideas under research and for practical application. 相似文献
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In this paper a new non-destructive testing (NDT) system focusing on micro size superficial defects in metallic joints is presented. The innovative system is composed by a new type of eddy currents probe, electronic devices for signal generation, conditioning and conversion, automated mechanized scanning and analysis software. The key original aspect of this system is the new type of eddy currents probe. This new probe provides enhanced lift-off immunity and improved sensitivity for micro size imperfections. The probe concept was studied using a Finite Element Method (FEM) tool and experimental verified using a standard defect. 相似文献