Effect of processing parameters on microhardness and microstructure of a double-sided dissimilar friction stir welded aa6082-t6 and aa7075-t6 aluminum alloy (original) (raw)
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Materials
The present study investigates the effect of two parameters of process type and tool offset on tensile, microhardness, and microstructure properties of AA6061-T6 aluminum alloy joints. Three methods of Friction Stir Welding (FSW), Advancing Parallel-Friction Stir Welding (AP-FSW), and Retreating Parallel-Friction Stir Welding (RP-FSW) were used. In addition, four modes of 0.5, 1, 1.5, and 2 mm of tool offset were used in two welding passes in AP-FSW and RP-FSW processes. Based on the results, it was found that the mechanical properties of welded specimens with AP-FSW and RP-FSW techniques experience significant increments compared to FSW specimens. The best mechanical and microstructural properties were observed in the samples welded by RP-FSW, AP-FSW, and FSW methods, respectively. Welded specimens with the RP-FSW technique had better mechanical properties than other specimens due to the concentration of material flow in the weld nugget and proper microstructure refinement. In both...
Journal of Materials Science, 2012
Dissimilar friction stir welds of aluminum alloys AA5086 in annealed and AA6061 in T6 temper conditions were investigated in terms of residual stress, grain structure and precipitation distribution in different zones of the welded joints. Optical metallography and transmission electron microscopy were used to characterize microstructures of different zones of the welds. In addition, residual stress profile and local mechanical properties of different zones were evaluated employing X-ray diffraction method and digital image correlation technique. It was found that softening in the AA6061-T6 side occurs in regions with weld peak temperature higher than 300°C. The micro-hardness profile results and TEM investigations also showed that thermo-mechanical affected zone of AA6061 side with large plate-shaped b precipitates is the softest region of the joints in AA6061 side. Furthermore, residual stress distribution within the samples is not directly dependent on the local mechanical properties of different zones of the joints.
Microstructural Evaluation of Friction Stir Welded Aluminium Alloy 6063
International Journal of Recent Technology and Engineering (IJRTE), 2019
Friction Stir Welding (FSW) is a vital solid-state process that can produce a joint with high quality and strength. The microstructure of the friction stir welded parts needs to be studied to use this method for multiple applications. FSW eliminates fusion fastening issues such as crack, porosity, and shrinking solidification. In the present work, AA6063 material was welded with prominent parameters, rotational speed, transverse speed, and axial load. The microstructure of distinct weld regions including the nugget area, heat affected zone, thermo-mechanically affected zone, and parent metal has been examined by optical microscopy. In this investigation the fine equiaxed grains were observed in the thermo-mechanically affected zone and nugget zone of various samples.
The effect of processing parameters on mechanical and microstructural properties of aluminium alloy 6082-T6 Friction stir-welded (FSW) joints were investigated in the present study. Different welded specimens were produced by employing variable rotating speeds and welding speeds. Tensile strength of the produced joints was tested at room temperature and the correlation with process parameter was assessed. Microstructures of various zones of FSW welds are presented and analyzed by means of optical microscopy and microhardness measurements. Several studies have been conducted to investigate the properties and microstructural changes in Friction Stir Welds in the aluminium alloy 6082-T6 in function of varying process parameters. The experimental results indicated that the process parameters have a significant effect on weld macrostructure and mechanical properties of joints.
In the present study, four pairs of 6061 aluminium alloy workpieces with different surface roughness were prepared for welding. The friction stir welding (FSW) technique was used for a butt-joint configuration of a single pass. The influence of different surface roughness of the workpieces coincided with a small welding tool shoulder diameter, and the tool pin was examined. The results demonstrated that spherical nano-sized grains of the joints were produced. The mechanical properties of the joints were significantly better at the least possible workpiece surface roughness. The experimental results also indicated that the tensile strength of FSW 6061 aluminium alloy was notably affected by joining at the different workpiece surface roughness selected. However, an improvement of the Vickers microhardness in the heat affected zone (HAZ) was also observed. The microhardness in the nugget zone (NZ) for the welded joint fabricated at the lowest value of the workpiece surface roughness was higher than that of the base metal (BM). The fractural surface of the cross-section of the tensile specimens has a gradient to change from brittle fracture to ductile fracture.
Archive of Mechanical Engineering, 2014
Friction stir welding is a solid state innovative joining technique, widely being used for joining aluminium alloys in aerospace, marine automotive and many other applications of commercial importance. The welding parameters and tool pin profile play a major role in deciding the weld quality. In this paper, an attempt has been made to understand the influences of welding speed and pin profile of the tool on friction stir welded joints of AA6082-T6 alloy. Three different tool pin profiles (tapered cylindrical four flutes, triangular and hexagonal) have been used to fabricate the joints at different welding speeds in the range of 30 to 74 mm/min. Microhardness (HV) and tensile tests performed at room temperature were used to evaluate the mechanical properties of the joints. In order to analyse the microstructural evolution of the material, the weld’s cross-sections were observed optically and SEM observations were made of the fracture surfaces. From this investigation it is found that...
— Objective: Friction stir welding (FSW) is a relatively new solid state welding technique for similar and dissimilar materials, especially on current interest with Aluminium 6061 to Aluminim 6061. Method/Analysis: The present paper discusses the process parameters followed by mechanical properties and microstructures which affect the weld strength. Findings: Mechanical properties-Tensile strength attained with different process parameters and Microstructures are obtained by Optical Metallurgical Microscopy (MET SCOPE-1) and a Scanning Electron Microscopy equipped with an X-radiation detector EDS Conclusion/Application: In this study Similar FSW between Al 6061 to Al 6061 plates with thickness 6mm were performed. The future research will contain creep tests and microstructural investigations using aluminium 6061 alloy using TEM microscopy (Transmission Electron Microscopy).It is demonstrated that FSW of aluminium to aluminium alloys is becoming an emerging technology with numerous commercial applications.
Advances in Materials Science and Engineering, 2022
In this research work, an attempt was made to weld AA7075 alloy using the friction stir welding (FSW) technique. e experimental runs were designed using the Taguchi L18 orthogonal array and welds were obtained by varying tilt angle, tool rotation speed, tool feed rate, and axial load, whereas weld quality was accessed in terms of tensile strength and microhardness. e microstructure was examined using an optical microscope. e studies revealed that the tool angle was the most in uential factor followed by the tool feed rate as both the parameters impacted the intensity of heat developed. It was observed that the tool tilt decreased the microhardness of the welds. e UTS values and macrostructure imply that the weld should be subjected to higher tool torque conditions. e material ow was not periodic nor coordinated, as seen by the tool-tilted weld's macrostructure. With a tool tilt, the weld pressure is lowered, and the lower pressure could not be enough to prevent volumetric defects. e reduced pressure at quicker welding rates may have had an e ect on the development of aws.
Metals
Friction stir welding of aluminum alloys has been progressively used in different industries on the ground of higher welding quality in comparison to fusion welding. In this article, friction stir welding of 6061-T6 aluminum alloy with 9.6 mm thickness was carried out by using three different welding speeds (63, 89 and 110 mm/min). The effect of welding speed on macro-and microstructure, micro hardness, tensile properties and kissing bond was investigated. Results show that the Low Hardness Zone was moved toward the weld center by increasing the welding speed. The average micro hardness in the weld nugget zone increased from 60.1 to 67.6 HV with the raise of welding speed from 63 to 110 mm/min. Thermo Mechanical Affected Zone was clearly revealed using Electron backscatter diffraction (EBSD). The kissing bond was studied by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) mapping. It was proven that the damaging effect of kissing bond was linked to location of this discontinuity, although the growth of kissing bond was linked to higher welding speed. The maximum value of Ultimate Tensile Strength (UTS) (159 MPa) was obtained at 110 mm/min, whereas the Yield Strength (YS) in the sample at 89 and 110 mm/min welding speed exhibit the same trend with 137 MPa and 134 MPa respectively.
Study on Impact of Microstructure and Hardness of Aluminium Alloy After Friction Stir Welding
— The effects of friction stir welding (FSW) on the microstructure and hardness of rolled pure aluminium 6061 were investigated. The weld was obtained by varying its tilt angle (2°) and Pin diameter (6mm). Tensile strength & % Elongation was carried out to evaluate the strength of the weld. Optical microscope study was carried out to study the uniform stirring of materials. The stir zone (SZ) contains fine, equiaxed and fully recrystallized grains. Thermo mechanically-affected zone (TMAZ), heat-affected zone (HAZ), and base material (BM) were different. Hardness test indicated that the minimum and maximum hardness values were obtained in the HAZ and BM, respectively.