Showing 5 results for Friction Stir Welding
M. Goodarzi, S. M. A. Boutorabi, M. A. Safarkhanian,
Volume 6, Issue 3 (9-2009)
Abstract
Abstract:In this study, an effort has been made to determine the influence of rotational speed of tool on themicrostructure and hardness values of friction stir welded 2024-T851 aluminum alloy. The microstructure of stir zonein the joints has been investigated. It was found that the particles such as Al6(CuFeMn) particles are broken up duringfriction stir welding, and the degree of break up of these particles in the stir zone increases with increasing rotationalspeed. Since the break up of these particles and the recrystallization of new grains happen simultaneously, the brokenparticles would be placed in the grain boundaries. Moreover, the hardness value in the stir zone increases withincreasing rotational speed
E. Gharibshahiyan, A. Honarbakhsh Raouf,
Volume 13, Issue 4 (12-2016)
Abstract
Friction welding is widely used in various industries. In friction welding, heat is generated by conversion of mechanical energy into thermal energy at the interface the work pieces during pin rotation under pressure. A three-dimensional thermo mechanical simulation of friction stir welding (FSW) processes is carried out for Aluminium Alloys of 6061and 7050 where the simulation results are compared directly with the measured temperature histories during FSW after process. The objective of the present work is to study and predict the heat transient generated in alloy aluminium plate welded by FSW method. A three dimensional model was developed by LS-Dyna software and heat cycles have been proposed during the welding of aluminium alloys 6061 and 7050. In this research, the simulations were carried out with linear velocity in the range of 140 to 225 mm/min and pin rotational speeds of 390 and 500 rpm. Increase in pin rotational speed, from 390 to 500 rpm, resulted in greater temperatures which translated to rise of recorded temperature of top and bottom of the specimens. This is in turn to a wider HAZ. In addition, it was observed that raising the linear velocity had an opposite effect. Finally, results of experimental and numerical data were correlated and validated
M. Alvand, M. Naseri, E. Borhani, H. Abdollah-Pour,
Volume 15, Issue 1 (3-2018)
Abstract
Friction stir welding (FSW) is a promising technique to join aluminum alloys without having problems encountered during fusion welding processes. In the present work, the evolution of microstructure and texture in friction stir welded thin AA2024 aluminum alloy are examined by electron backscattered diffraction (EBSD) technique. The sheets with 0.8 mm thickness were successfully welded by friction stir welding at the tool rotational speeds of 500, 750, and 1000 rpm with a constant traverse speed of 160 mm/min. EBSD revealed that stir zones exhibited equiaxed recrystallized grains and the grain size increased with increasing the tool rotation rate. The fraction of high angle grain boundaries and mean misorientation angle of the boundaries in the FSW joints at 500 rpm were 63.6% and 24.96°, respectively, which were higher than those of the sample welded at 1000 rpm (53.6% and 17.37°). Crystallographic texture results indicated that the Cube {001}<100> and S {123}<634> textures in base metal gradually transformed in to Copper {112}<111> shear texture. It was found that with increasing the tool rotation rate, the intensity of Cube {001}<100>, Y {111}<112>, S {123}<634>, and Dillamore {4 4 11}<11 11 8> texture orientations increased and the intensity of Brass {011}<211> texture orientation decreased.
M. Naseri, M. Alipour, A. Ghasemi, E. Davari,
Volume 15, Issue 1 (3-2018)
Abstract
One of the interesting state-of-the-art approaches to welding is the process of friction stir welding (FSW). In comparison with the fusion processes, FSW is an advantageous method as it is suitable for the non-fusion weldable alloys and polymeric materials joining. Regarding the materials pure solid state joining, it also provides joints with less distortion and enhanced mechanical properties. In the present work, a three-dimensional (3D) model based on finite element analysis was applied to study the thermal history and thermomechanical procedure in friction stir welding of high density polyethylene plate. The technique includes the tool mechanical reaction and the weld material thermomechanical procedure. The considered heat source in the model, includes the friction among three items: the material, the probe and the shoulder. Finally, the model was validated by measuring actual temperatures near the weld nugget using thermocouples, and good agreement was obtained for studied materials and conditions.
Padmanaban Ramasamy,
Volume 21, Issue 2 (6-2024)
Abstract
The present investigation delves into the friction stir welding of AA5052 and AZ31B alloys, examining the effects of three distinct parameter configurations. A face-centered central composite design, structured to incorporate full replications for comprehensive and reliable analysis, was employed. A pivotal element of this study is implementing an advanced deep neural network (DNN) model. Characterized by its varied activation functions, structural parameters, and training algorithms, this DNN model was adeptly configured to precisely predict the tensile strength and microhardness of the welded joints. This comprehensive examination also included a quantitative assessment of the parameter effects on joint microstructure and mechanical properties. Flawless welds with exemplary surface characteristics were attained through a meticulously optimized set of parameters: a tool rotation speed set at 825 rpm, a tool traverse speed of 15 mm/min, and a shoulder diameter of 18 mm. During the welding process, the formation of intermetallic compounds, specifically Al12Mg17 and Al3Mg2, was observed. An exceptionally refined grain size of 2.23 µm was observed in the stir zone, contributing to the joint's enhanced tensile strength, measured at 180 MPa. The hardness of the specimen fabricated at the high rotational speed is more elevated due to the brittle intermetallic compounds. The better mechanical properties are related to the reduction and distribution of intermetallic compounds formed in the interface zone.
