Airframe Alloys

2006

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.

2013

Friction-stir welding (FSW), a solid-state innovative joining technique, is being widely used for joining aluminium alloys for the aerospace, marine, automotive industries and many other applications of commercial importance. FSW trials were carried out using a vertical machining centre (VMC) on an AA6061 alloy. The main objective of the present work was to evaluate the weld-processing parameters of FSW for the AA6061-T6 alloy and to determine the properties of the obtained joints with respect to the welding speed. The experiments were conducted by varying the welding speed between 55–70 mm/min and the rotating speed was fixed at 1700 r/min. The tensile properties, microstructure, microhardness, fractography and corrosion resistance of the FSW joints were investigated in this study. The result showed that there was a variation in the grain size in each weld zone depending upon the material and the process parameters of FSW in a joint. The coarsest grain size was observed in the heat...

2016

The effect of processing parameters on the mechanical and metallurgical properties of dissimilar joints of AA6082–AA6061 produced by friction stir welding was analysed in this study. Different FSW samples were produced by varying the welding speeds of the tool as 50 and 62 mm/min and by varying the alloy positioned on the advancing side of the tool. In all the experiments the rotating speed is fixed at 1600rpm. All the welds were produced perpendicularly to the rolling direction for both the alloys. 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. The corrosion tests of base alloy and welded joints were carried out in 3.5%NaCl solution at a room temperature. Corrosion current and potential were determined using potentiostatic polari...

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.

international journal of advanced design and manufacturing technology, 2013

Abstract: Friction stir welding, a solid state innovative joining technique, is widely being used for joining aluminium alloys for aerospace, marine automotive and many other applications of commercial importance. FSW trials were carried out using a vertical machining centre (VMC) on AA6061 alloy. The main objective of the present work was to evaluate the weld processing parameter of friction stir weld (FSW) process for AA6061-T6 alloy and to determine the properties of the obtained joints with respect of welding speed. Experiments have been conducted by varying the welding speed of 55-70 mm/min and the rotating speed was fixed at 1700rpm. Tensile properties, microstructure, microhardness, fractography, and corrosion resistance of FSW joints were investigated in this study. The result showed that there was a variation of grain size in each weld zone which depends upon the material and process parameters of FSW in the joint itself. The coarsest grain size was observed in heat affec...

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...

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.

Al alloy is widely used for commercial applications in the transportation, construction and similar engineering industries. It possesses excellent mechanical properties in addition to good corrosion resistance. In this experiment, Friction Stir welding to obtain the butt joints of similar and dissimilar aluminum alloys i.e. (AA6061-6061, AA6082-6082 & AA6061-6082 under T6 condition) is carried out and NDT testing (penetrate and ultrasonic tests) to detect any weld defects present in the welded area, which reveals a good acceptance. Micro hardness and micro structure in the weld is examined. The Microstructure evaluation of AA6061 shows that the Fusion with parent metal is good, Grains are slightly elongated at the heat affected zone at similar welds, Microstructure evaluation of AA6082 similar weld shows that grains are slightly decreased at HAZ and Microstructure evaluation of AA6082 and AA6061 dissimilar weld shows that grains are slightly elongated at welded zone than a base metal AA6061 and same as a grain size of base metal AA6082. Vickers Micro hardness evaluation of AA6061-AA6061 shows that after Friction Stir welding (FSW) at parent metal Vickers Micro hardness slightly higher than weld zone. Vickers Micro hardness is high at HAZ for AA6061. Vickers Micro hardness of AA 6082-6082 at the weld region is higher than HAZ, Parent metal. Vickers Micro hardness of AA 6061-6082 at the weld region is higher than HAZ. By comparing the three welded joints Vickers Micro hardness of AA6061-AA6082 is higher than similar welds (AA6061-AA6061 & AA6082-AA6082) at welded region, at HAZ Vickers Micro hardness AA6061-A6061 is higher than the other two welded joints.

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...

The main objective of this research is to conduct an investigation into the effect of welding parameters on the microstructural and mechanical properties of friction stir (FS) welded butt joints of dissimilar aluminum alloy AA6061 and AA7075. Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. This will be used to join aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. In this process, two metal pieces, AA6061 and AA7075, 100 x 50 x 6mm thick, are welded under different welding parameters like tool rotation speed and transverse feed. The effects of welding parameters were evaluated by studying the resulting mechanical properties such as hardness distribution and tensile properties for axial welded zone.