scholarly journals Microstructural and Mechanical Behaviors of Friction Stir Welded Dissimilar AA6082-AA7075 Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
M. Vetrivel Sezhian ◽  
K. Giridharan ◽  
D. Peter Pushpanathan ◽  
G. Chakravarthi ◽  
B. Stalin ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Rotational Speed ◽  
Bending Strength ◽  
Tensile Specimen ◽  
Al Alloy ◽  
Tool Rotational Speed ◽  
Mechanical Behaviors ◽  
Friction Stir ◽  
Weld Joints ◽  
Joint Quality

In this research, microstructural events and mechanical behaviors in dissimilar friction stir welding (FSW) of aluminium (Al) alloy AA6082-AA7075 joints have been evaluated to apply aerospace, defense, and military sectors. FSW parametric effects have a more significant impact on the mechanical performances and microstructure of produced joints. FSW tool rotational speed, welding speed, and tool plunge speed were chosen to make the weld joints. The rotational tool speeds of 1600 rpm and 2300 rpm, welding speeds of 40 mm/min and 60 mm/min, and tool plunge speeds of 20 mm/min and 30 mm/min were set as the upper and lower limits. A constant axial force of 5 kN was maintained throughout the joint fabrication process. A taper pin-profiled tool was utilized to produce the butt welded joints. Mechanical properties of microhardness, tensile strength, yield strength, elongation, and bending strength of the joints were analyzed. The response of the stir zone microstructure to processing parameters was evaluated using optical microscopy (OM) and fractographic analysis of a tensile specimen shown by scanning electron microscope (SEM). The weld joints produced at 2300 rpm, tool traveling rate of 40 mm/min, and tool plunge speed of 30 mm/min showed the greatest tensile strength of the 191 MPa hardness of 145 Hv at the weld center and also the maximum bending strength of 114.23 N/mm2 was achieved. The lowest bending strength of 25.38 N/mm2 was obtained at 1600 rpm with 60 mm/min due to inappropriate mixing of the base metals and poor joint quality. Furthermore, this study revealed that a higher tool plunge speed facilitates the formation of equiaxed grains in the thermomechanically affected zone (TMAZ) on the advancing side (AS). Additionally, the increment in tool rotational speed significantly improved the tensile strength, weld joint quality, and joint efficiency.

Comparison of response surface methodology with artificial neural network for prediction of the tensile properties of friction stir-processed surface composites

2021 ◽  
pp. 095440892110368
Author(s):  
Ravi Butola ◽  
Ranganath M. Singari ◽  
Qasim Murtaza ◽  
Lakshay Tyagi
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Tensile Strength ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Rotational Speed ◽  
Total Elongation ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Artificial Neural

In the present work, nanoboron carbide is integrated in the aluminum matrix using friction stir processing: by varying process parameters, that is, tool pin profile, tool rotational speed and tool traverse speed, based on Taguchi L16 design of experiment. A self-assembled monolayer is successfully developed on the substrate to homogeneously and uniformly distribute the reinforcement particles. Response surface methodology and artificial neural network models are developed using ultimate tensile strength and total elongation as responses. Percentage absolute error between the experimental and predicted values of ultimate tensile strength and total elongation for the response surface methodology model is 3.537 and 2.865, respectively, and for artificial neural network is 2.788 and 2.578, respectively. For both the developed models experimental and forecasted values are in close approximation. The artificial neural network model showed slightly better predictive capacity compared to the response surface methodology model. From the scanning electron microscopy micrograph, it is evident that throughout the matrix B4C reinforcement particles are well distributed also; with increasing tool rotational speed grain size decreases up to 1200 r/min; on further increasing the tool rotational speed particles starts clustering.

Effect of Al2O3 nanoparticles on microstructure and mechanical properties of friction stir-welded dissimilar aluminum alloys AA7075-T6 and AA6061-T6

2021 ◽  
pp. 095440892110655
Author(s):  
Sumit Jain ◽  
R.S. Mishra
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Particle Dispersion ◽  
Al2o3 Nanoparticles ◽  
Tool Rotational Speed ◽  
Micro Hardness ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys

In this research, a defect-free dissimilar weld joint of AA7075-T6 and AA6061-T6 reinforced with Al2O3 nanoparticles was fabricated via friction stir welding (FSW). The influence of tool rotational speed (700, 900 and 1100 rpm), traverse speed (40, 50 and 60 mm/min) with varying volume fractions of Al2O3 nanoparticles (4%, 7% and 10%) on microstructural evolution and mechanical properties were investigated. The augmentation of various mechanical properties is based on the homogeneity of particle dispersion and grains refinement in the SZ of the FSWed joint. The findings revealed that the remarkable reduction in grain size in the SZ was observed owing to the incorporation of Al2O3 nanoparticles produces the pinning effect, which prevents the growth of grain boundaries by dynamic recrystallization (DRX). The increasing volume fraction of Al2O3 nanoparticles enhanced the mechanical properties such as tensile strength, % elongation and micro-hardness. Agglomeration of particles was observed in the SZ of the FSWed joints produced at lower tool rotational speed of 700 rpm and higher traverse speed of 60 mm/min due to unusual material flow. Homogenous particle dispersion and enhanced material mixing ensue at higher rotational speed of 1100 rpm and lower traverse speed of 40 mm/min exhibit higher tensile strength and micro-hardness.

Optimization of friction stir welding process parameters for AA6063-ETP copper using central composite design

2020 ◽  
Vol 17 (4) ◽  
pp. 491-507 ◽  
Author(s):  
Nitin Panaskar ◽  
Ravi Prakash Terkar
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Traverse Speed ◽  
Tool Rotational Speed ◽  
Content Type ◽  
Friction Stir ◽  
Central Composite

Purpose Recently, several studies have been performed on lap welding of aluminum and copper using friction stir welding (FSW). The formation of intermetallic compounds at the weld interface hampers the weld quality. The use of an intermediate layer of a compatible material during welding reduces the formation of intermetallic compounds. The purpose of this paper is to optimize the FSW process parameters for AA6063-ETP copper weld, using a compatible zinc intermediate filler metal. Design/methodology/approach In the present study, a three-level, three-factor central composite design (CCD) has been used to determine the effect of various process parameters, namely, tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil on ultimate tensile strength of the weld. A total of 60 experimental data were fitted in the CCD. The experiments were performed with tool rotational speeds of 1,000, 1,200 and 1,400 rpm each of them with tool traverse speeds of 5, 10 and 15 mm/min. A zinc inter-filler foil of 0.2 and 0.4 mm was also used. The macrograph of the weld surface under different process parameters and the tensile strength of the weld have been investigated. Findings The feasibility of joining 3 mm thick AA6063-ETP copper using zinc inter-filler is established. The regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination (R2) value of 0.9759 and model F-value of 240.33. A good agreement between the prediction model and experimental findings validates the reliability of the developed model. The tool rotational speed, tool traverse speed and thickness of inter-filler zinc foil significantly affected the tensile strength of the weld. The optimal conditions found for the weld were, rotational speed of 1,212.83 rpm and traverse speed of 9.63 mm/min and zinc foil thickness is 0.157 mm; by using optimized values, ultimate tensile strength of 122.87 MPa was achieved, from the desirability function. Originality/value Aluminium and copper sheets could be joined feasibly using a zinc inter-filler. The maximum tensile strength of joints formed by inter-filler (122.87 MPa) was significantly better as compared to those without using inter-filler (83.78 MPa). The optimum process parameters to achieve maximum tensile strength were found by CCD.

scholarly journals Effect of Tool Rotational Speeds on Friction Stir Welded AA6082-T6 Aluminium Alloy Joints

2020 ◽  
Vol 9 (1) ◽  
pp. 62-67
Keyword(s):  
Tensile Strength ◽  
Aluminium Alloy ◽  
Rotational Speed ◽  
Mechanical Characteristics ◽  
Weld Zone ◽  
Grain Structure ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Average Grain Size ◽  
Equiaxed Grain

In the current work, an attempt has been made to investigate the effect of tool rotational speed on microstructural and mechanical properties of friction stir welded AA6082-T6 aluminium alloy. Four different tool rotational speeds such as 500, 700, 900 and 1100 rpm were used to produce the joints while keeping the other process parameters constant. The tool used to fabricate the welded samples was tungsten carbide with straight cylindrical pin profile. The microstructural properties were examined using an optical and scanning electron microscope and found that the 700 rpm produced joint showed equiaxed grain structure with 14.3 µm average grain size. The mechanical characteristics such as tensile strength, impact strength and microhardness were evaluated and found the highest tensile strength of 265 MPa, impact energy of 10 J and micro hardness of 76 HV in the weld zone for the sample prepared with 700 rpm tool rotational speed. The fractographic studies were also carried out to study the mode of failure.

Analysis of process parameters effects on underwater friction stir welding of aluminum alloy 6082-T6

2018 ◽  
Vol 233 (6) ◽  
pp. 1700-1710 ◽  
Author(s):  
Mohd Atif Wahid ◽  
Zahid A Khan ◽  
Arshad Noor Siddiquee ◽  
Rohit Shandley ◽  
Nidhi Sharma
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Rotational Speed ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Underwater Friction Stir Welding ◽  
Optimal Setting

In friction stir welding of heat treatable aluminum alloys, the thermal cycles developed during the joining process result in softening of the joints which adversely affect their mechanical properties. Underwater friction stir welding can be a process of choice to overcome this problem due to low peak temperature and short dwell time involved during the process. Consequently, this article presents a study pertaining to the underwater friction stir welding of aluminum alloy 6082-T6 with an aim to develop a mathematical model to optimize the underwater friction stir welding process parameters for obtaining maximum tensile strength. The results of the study reveal that the tool shoulder diameter (d), tool rotational speed (ω), welding speed (v), and second-order term of rotational speed, that is, ω2, significantly affect the tensile strength of the joint. The maximum tensile strength of 241 MPa which is indeed 79% of the base metal strength and 10.7% higher than that of conventional (air) friction stir welding joint was achieved at an optimal setting of the underwater friction stir welding parameters, that is, tool rotational speed of 900 r/min, the welding speed of 80 mm/min, and a tool shoulder of 17 mm. The article also presents the results of temperature variation, the macrostructural and microstructural investigations, microhardness, and fractography of the joint obtained at the optimal setting for underwater friction stir welded (UFSWed) joint.

Investigations on microstructural and mechanical properties of friction stir welded AA 2024-T351

2020 ◽  
Vol 62 (8) ◽  
pp. 793-802
Author(s):  
Şefika Kasman ◽  
Sertan Ozan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Rotational Speed ◽  
Stir Zone ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Aa 2024

Abstract In the present study, AA 2024-T351 plates with a thickness of 6 mm were joined using the friction stir welding technique with three different tool rotational speeds and two different pin profiles. Microstructural features and mechanical properties of welded joints were investigated. The grains in recrystallized regions along the stir zone were observed to be almost with invariable sizes. The grain size was revealed to increase with the increase in tool rotational speed. The average grain size was observed to dramatically increase from 2.3 μm to 5.6 μm for welded joints produced with pentagonal shaped pin. All the welded joints were observed to contain defects; the presence of defects exhibited a negative effect on the tensile properties of the welded joint. Most of the defects were observed to localize at the root region of joints. The joint, welded with the tool rotational speed of 250 rpm using pentagonal shaped pin, exhibited ultimate tensile strength with a value of 365 MPa. The ultimate tensile strength of welded joints was found to be higher with the decrease in the tool rotational speed. The welding efficiency of joints was compared with the ultimate tensile strength of base metal; notably, welding efficiency values between 46 % and 80 % were achieved. Microstructural characterizations revealed that Al2Cu (θ phase), Al2CuMg (S phase), and AlCuFeMnSi, Al7Cu2Fe intermetallic particles were dispersed in the stir zone.

Experimental Analysis on Mechanical Properties of Friction Stir Welding in Dissimilar Aluminum Alloys

2020 ◽  
pp. 64-68
Author(s):  
Anganan K ◽  
Narendran RJ ◽  
Naveen Prabhu N ◽  
Rahul Varma R ◽  
Sivasubramaniyam R
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Welding Speed ◽  
Rotational Speed ◽  
Copper Alloys ◽  
Welding Parameters ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Dissimilar Aluminum Alloys

Friction stir welding (FSW) is an innovative solid state joining technique and has been employed in industries for joining aluminum, magnesium, zinc and copper alloys. The FSW process parameters such as tool, rotational speed, welding speed, axial force, etc play major role in deciding the weld quality. A mathematical modeling was developed based on experiments to predict the tensile strength of dissimilar FSW aluminum alloys. The maximum tensile strength of 210 MPa can be obtained at the tool rotational speed of 1100 rpm, welding speed of 35mm/min and an axial load of 7 kN is the Optimum welding parameters.

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