Path Force Control for Friction Stir Welding Processes

Author(s):  
Xin Zhao ◽  
Prabhanjana Kalya ◽  
Robert G. Landers ◽  
K. Krishnamurthy

In Friction Stir Welding (FSW) processes, force control can be used to achieve good welding quality. This paper presents the systematic design and implementation of a FSW path force controller. The path force is modeled as a nonlinear function of the FSW process parameters (i.e., plunge depth, tool traverse rate, and tool rotation speed). An equipment model, which includes a communication delay, is constructed to relate the commanded and measured tool rotation speed. Based on the dynamic process and equipment models, a feedback controller for the path force is designed using the Polynomial Pole Placement technique. The controller is implemented in a Smith Predictor–Corrector structure to compensate for the inherent equipment communication delay and the controller parameters are tuned to achieve the best closed loop response possible given equipment limitations. In the path force controller implementation, a constant path force is maintained, even in the presence of gaps, and wormhole generation during the welding process is eliminated by regulating the path force.

Author(s):  
Tarmizi Tarmizi ◽  
Riki Indrawan ◽  
Irfan Irfan

PENGARUH TOOL ROTATION SPEED TERHADAP SIFAT MEKANIK SAMBUNGAN ALUMINIUM PADUAN 6061 T6 PADA PROSES FRICTION STIR WELDING. Pengelasan aduk tekan merupakan proses pengelasan yang baru dikembangkan pada tahun 1991, hingga saat ini berbagai penelitian terus dilakukan untuk menemukan parameter yang dapat menghasilkan sambungan las yang optimum sebagai alternatif proses pengelasan fusi yang masih memiliki beberapa kekurangan. Penelitian ini bertujuan untuk mengetahui pengaruh kecepatan putar tool yang menjadi salah satu parameter penting dalam friction stir welding pada pelat aluminium paduan 6061-T6 dengan tebal 6 mm terhadap sifat mekanik sambungan las, dengan variasi kecepatan putar yang digunakan 910 rpm, 1175 rpm, 1555 rpm, 1700 rpm dan 2000 rpm untuk mendapatkan parameter yang optimum. Berdasarkan penelitian yang telah dilakukan didapatkan hasil bahwa sambungan las dengan kecepatan putaran 910 rpm, 1175 rpm dan 1555 rpm tidak terdapat cacat dan memenuhi kriteria sambungan las berdasarkan standar AWS D17.3 sedangkan sambungan las yang memiliki sifat mekanik yang paling optimum yaitu sambungan las dengan kecepatan putar tool 910 rpm karena pengkasaran butir dan larutnya presipitat tidak terlalu signifikan dibandingkan dengan kecepatan putaran lainnya.Kata kunci: Pengelasan aduk tekan, pengelasan fusi, kecepatan putar, tool, aluminium paduan 6061-T6.


Author(s):  
Jaishree Sanjeevi Maran ◽  
Pratyush Kumar Patro ◽  
Ilangovan Murugesan ◽  
Sai Krishna Sekar ◽  
Sidhaarth Bamarani Thangaswamy

Friction Stir processing, a novel welding process which weld similar and dissimilar metals and alloys in solid state for joining metallic alloys and it has replaced conventional welding processes and have become an alternative welding technique. The commonly used aluminum alloys AA6061 and AA5086 were joined together using FSW. In this study, two parameters such as weld speed and tool rotation speed are taken into account. By varying these parameters the dissimilar alloys were welded together. The welded joints were analyzed for its chemical composition and phases formed due to heat produced by friction. The composition is characterized by Electron Back Scattered Diffraction technique (EBSD) and X-ray Diffraction technique (XRD). The influence of tool rotation speed and weld speed on texture has been studied.


2016 ◽  
Vol 27 (1) ◽  
pp. 9-17
Author(s):  
Maryati Maryati ◽  
Bambang Soegijono ◽  
M Yudi Masduky ◽  
Tarmizi Tarmizi

Friction Stir Welding (FSW) is a new method of welding process which is affordable and provide good quality. Aluminium 5083-7075 has been connected successfully by using friction stir welding (FSW) method into butt joint connection form. Tool rotation speed is one of the important parameters in FSW. The changes of rotation speed will affect the characteristics of mechanical properties and microstructure. The parameters of welding being used are welding speed of 29 mm/minutes by varying the speed rotation of 525 rpm, 680 rpm, 910 rpm, and 1555 rpm. In order to find out the mechanical strength of welds, tensile strength and hardness testing is done while finding out the microstructure will be done by using optical microscope and Scanning Electron Microscope (SEM). The result of the research showed that the highest tensile strength obtained at 910 rpm speed rotation about 244.85 MPa and the greatest hardness values was found on aluminium 5083 around the wheel zone area about 96 HV with rotary speed of 525 rpm. Then, the result of testing the macro and microstructure on all samples indicated defect which is seen as incomplete fusion and penetration causing the formation of onion rings. In other words, it is which showed that the result of stirring and tacking in the welding area is less than perfect.


2018 ◽  
Vol 106 (6) ◽  
pp. 606 ◽  
Author(s):  
İnan Geçmen ◽  
Zarif Çatalgöl ◽  
Mustafa Kemal Bilici

Friction stir welding is a method developed for the welding of high-alloy aluminum materials which are difficult to combine with conventional welding methods. Friction stir welding of MS 63 (brass) plates used different tools (tapered cylindrical, tapered threaded cylindrical), tool rotational speeds (1040, 1500, 2080 rpm) and traverse speeds (30,45,75,113 mm.min−1). Tensile, bending, radiography and microstructure tests were carried out to determine the mechanical properties of brass plates joined by friction stir welding technique. Microstructure characterization studies were based on optical microscope and SEM analysis techniques. In addition, after joining operations, radiographs were taken to see the internal structure failure. Brass sheets were successfully joined to the forehead in the macrostructure study. In the evaluation of the microstructure, it was determined that there were four regions of base metal, thermomechanically affected zone (TMEB), heat-affected zone (HAZ) and stir zone. In both welding tools, the weld strength increased with increasing tool rotation speed. The particles in the stir zone are reduced by increasing of the tool rotation speed. Given the strength and % elongation values, the highest weld strength was achieved with tapered pin tool with a tool rotation speed of 1040 rpm and a tool feed speed of 113 min−1.


Author(s):  
M. Sucharitha ◽  
B. Ravisankar

Friction stir welding could be a solid-state welding has a wide range of applications in industries like aerospace and automobile industries. In this work, the friction stir weld ability of aluminium metal matrix composite(AMMC) using H13 tool and sensitivity of parameters like tool rotation speed, traverse speed and axial force are assessed on final durability, hardness and microstructure. It was observed that the tensile strength and hardness are increased by increasing the tool rotation speed. The microstructure showed fine Al-Mg-Si eutectic particles in a matrix of Al solid solution.


2013 ◽  
Vol 787 ◽  
pp. 346-351
Author(s):  
Salar Salahi ◽  
Vahid Rezazadeh ◽  
Atabak Iranizad ◽  
Ali Hosseinzadeh ◽  
Amir Safari

As a novel technique for joining materials, friction stir welding (FSW) has significant advantages over the conventional welding methods and is widely applied for joining different materials including aluminum, magnesium and copper alloys. In this research, the mechanical and microstructural characteristics of friction stir welded annealed pure copper joints were investigated. The influence of the tool rotation speed, welding speed and applied load was studied. The friction stir welding (FSW) was conducted at welding speed ranged from 30 to 70 mm/ min, rotation speed ranged from 400 to 1200rpm and applied load ranged from 1000 to 1500 kg. After welding process, tensile and Vickers hardness tests were performed. It has been found that increasing the tool rotational speed and/or reducing the welding speed increases heat input and causes grain coarsening in stir zone. High applied load refines the microstructure of NZ and increases the hardness and tensile strength of NZ. An optimum heat input condition was found to reach the best mechanical properties of the joints. The tensile characteristics of the friction stir welded tensile samples depend significantly on the tool rotation speed ,welding speed and applied load.


Author(s):  
Xin Zhao ◽  
Prabhanjana Kalya ◽  
Robert G. Landers ◽  
K. Krishnamurthy

In friction stir welding (FSW) processes, force control can be used to achieve good welding quality. This paper presents the systematic design and implementation of FSW force controllers. The axial and path forces are modeled as nonlinear functions of the FSW process parameters (i.e., plunge depth, tool traverse rate, and tool rotation speed). Equipment models, which include communication delays, are constructed to relate the commanded and measured actuator signals. Based on the dynamic process and equipment models, nonlinear feedback controllers for the axial and path forces are designed using the polynomial pole placement technique. The controllers are implemented in a Smith predictor-corrector structure to compensate for the inherent equipment communication delays, and the controller parameters are tuned to achieve the best closed loop response possible given equipment limitations. In the axial force controller implementation, a constant axial force is maintained, even when gaps are encountered during the welding process. In the path force controller implementation, a constant path force is maintained, even in the presence of gaps, and wormhole generation during the welding process is eliminated by regulating the path force.


Sign in / Sign up

Export Citation Format

Share Document