Microstructure and mechanical properties of dissimilar friction stir welds of AA2014 and AA7075

2021 ◽  
pp. 095440892110581
Author(s):  
Raj Kumar ◽  
Vikas Upadhyay ◽  
Chaitanya Sharma
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Welding Speed ◽  
High Strength ◽  
Processing Parameters ◽  
Tensile Failure ◽  
Tensile Fracture ◽  
Hardness Profile ◽  
Friction Stir ◽  
Optical Micrograph

This work investigates the effect of process parameters on microstructure, mechanical properties, and fracture behavior of friction stir welded high-strength aluminum alloys AA2014-T6 and AA7075-T6. Optical micrograph, tensile property, and hardness profile of each weld were determined for analysis, and the tensile fracture surfaces were studied by scanning electron microscope. Welds microstructure were heterogeneous and displayed structures comprising of both base metals and the onion rings were seen in all welds except for the lowest heat input weld. Grains in the weld nugget zone were more refined on the retreating side than the other side. Asymmetric hardness profile had a distinct softened zone on each side whose location and softening extent varied with the processing parameters. Welding speed had a more significant effect on tensile strength than rotary speed and, drastically decreased the same. Faster welding speed formed microscopic defects and changed the appearance of fractured surfaces from flat to zigzag. The welds underwent ductile and mixed-mode tensile failure on the advancing side. Attainment of optimum combination of process parameters is imperative to yield defect-free stronger dissimilar welds

scholarly journals Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4211 ◽  
Author(s):  
Anton Naumov ◽  
Iuliia Morozova ◽  
Evgenii Rylkov ◽  
Aleksei Obrosov ◽  
Fedor Isupov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Welding Speed ◽  
Welded Joints ◽  
High Speed ◽  
Structural Characteristics ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Microhardness Distribution ◽  
Aluminum Sheets

The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations.

scholarly journals The influence of welding speed on mechanical properties of friction stir welded joints of AA2024 T351 aluminum alloy

2020 ◽  
Vol 70 (2) ◽  
pp. 53-57
Author(s):  
Miodrag Milčić ◽  
Igor Radisavljević ◽  
Zijah Burzić ◽  
Ljubica Radović ◽  
Tomaž Vuherer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Welding Speed ◽  
Flat Surface ◽  
Hardness Measurement ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Butt Joints ◽  
Friction Stir ◽  
Welding Direction

The aim of this study is to analyze how the process parameters affect the mechanical properties of butt joints obtained by friction stir welding (FSW). The experimental study was performed by the FSW of sheets having a thickness equal to 6 mm and made of aluminum alloys AA2024 T351, varying the process parameters, namely rotational speed and welding speed. The following welding parameters were used: the rotation speed of the tool did not change and amounted to 750 rpm, and the welding speed was 73, 116,150 mm / min. The welds were obtained without the presence of errors and with an acceptable flat surface of the compound. Tensile tests were performed orthogonally to the welding direction on specimens having the welding nugget placed in the middle of gage length. Vickers hardness measurement was conducted perpendicular to the welding direction, a cross-section of the weld joint. The hardness profiles were obtained along 3 horizontal and 63 vertical directions. Bend testing was carried out according to EN 910 The bending specimens were tested using face and root side of the joint in tension.

Mathematical Model to Predict Tensile Strength of Underwater Friction Stir Welded (UFSW) on 5052 Aluminium Alloys

2018 ◽  
Author(s):  
Dhanis Paramaguru ◽  
Srinivasa Rao Pedapati ◽  
Mokhtar Awang ◽  
Hamed Mohebbi
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Process Parameters ◽  
Welding Speed ◽  
Rotational Speed ◽  
Polynomial Regression ◽  
Coefficient Of Determination ◽  
Optimum Process ◽  
Tool Rotational Speed ◽  
Friction Stir

In this study, AA5052 joints are fabricated by underwater friction stir welding and the process parameters are optimized for maximum UTS value by utilizing a developed mathematical model. The experiments are conducted by using Taguchi’s L9 orthogonal array, and polynomial regression analysis is applied to generate the model. Statistical tools such as analysis of variance (ANOVA), coefficient of determination is applied to check the adequacy of the developed model at 95% confidence level. Type of welding tools is identified as the most influencing factor on deciding the mechanical properties of the joint, followed by tool rotational speed and tool welding speed. The optimum process parameters are identified by the Taguchi parametric design method. The results indicated that the optimum process parameters combinations for better mechanical properties is attained at tool rotational speed of 1500 rpm and tool welding speed of 100 mm/min, using taper threaded cylindrical tool. A maximum UTS value of 225.48 MPa is obtained and it is verified by confirmation test.

Influence of Welding Process Parameters on Microstructure and Mechanical Properties of Friction Stir Welded Aluminium Matrix Composite

2016 ◽  
Vol 880 ◽  
pp. 50-53 ◽  
Author(s):  
Subramanya Prabhu ◽  
Arun Kumar Shettigar ◽  
Karthik Rao ◽  
Shrikantha Rao ◽  
Mervin Herbert
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Welding Speed ◽  
Rotational Speed ◽  
Joint Strength ◽  
Welding Process ◽  
Aluminium Matrix ◽  
Friction Stir ◽  
Weld Region ◽  
Microstructure And Mechanical Properties

In this study, the effect of process parameters on microstructure and mechanical properties of friction stir welded aluminium matrix composites (AMC) have been explored. The results indicated that the recrystallized grain size at the bottom of the weld region is smaller than that at the top region due to difference in the heat transfer at the weld region. The joint strength of AMCs depends on proper selection of process parameters like tool rotational speed and welding speed. If process parameter values are beyond the optimal value, the joint strength decreases due to formation of defects. Maximum tensile strength is obtained for rotational speed of 1000 rpm and welding speed of 80mm/min.

Microstructure and Mechanical Properties of Friction Stir Welded Joints of Dissimilar AA6061-T6 and AA7075-T6 Aluminium Alloys

2015 ◽  
Vol 787 ◽  
pp. 350-354 ◽  
Author(s):  
V. Saravanan ◽  
Nilotpal Banerjee ◽  
R. Amuthakkannan ◽  
S. Rajakumar
Keyword(s):  
Mechanical Properties ◽  
Welding Speed ◽  
Rotational Speed ◽  
Axial Load ◽  
Microstructural Analysis ◽  
High Strength ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Proper Material

Dissimilar friction stir welding was carried out between AA6061-T6 and AA7075-T6 aluminum alloys. The effect of tool rotational speed and welding speed, on microstructure and mechanical properties were analysed in detail and presented. The tool rotational speed, welding speed, axial load and shoulder diameter to pin diameter (D/d ratio) were the parameters taken into consideration for the study. It was concluded that the tensile strength and hardness value gradually increased with the increase in tool rotational speed and decreased with the further increase in tool rotational speed. The microstructural analysis was carried out for the high strength specimen at various zones. Fine grain size and proper material mixing were observed in the stir zone. Fractographic image of the fractured surface for the high strength joint was presented and discussed. The joint fabricated with tool rotational speed 1000 RPM, welding speed 25 mm/min, axial load 6 kN and D/d ratio 3 exhibited superior mechanical properties when compared to all other joints.

Effect of Friction Stir Welding Process Parameters on the Mechanical Properties of AA 6061 Aluminum Alloy Using Taguchi Orthogonal Technique

2015 ◽  
Vol 813-814 ◽  
pp. 431-437 ◽  
Author(s):  
Singarapu Ugender ◽  
A. Kumar ◽  
A. Somi Reddy
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Tilt Angle ◽  
Welding Speed ◽  
Optimization Technique ◽  
Friction Stir ◽  
Tool Tilt Angle ◽  
Fsw Parameters

In this investigation, the effect of friction stir welding (FSW) parameters such as D/d ratio, tool tilt angle and welding speed on the mechanical properties of tensile strength, and impact energy of AA 6061 alloy was studied. The experiments were carried out as per Taguchi parametric design concepts and an L9 orthogonal array was used to study the influence of various combinations of process parameters. Statistical optimization technique, ANOVA was used to determine the optimum levels and to find the significance of each process parameter. The results indicate that D/d ratio, welding speed are the most significant factors, followed by tool tilt angle in deciding the mechanical properties of friction stir welding aluminum alloy.

scholarly journals The Effect of Process Parameters on Microstructural and Mechanical Properties of Friction Stir Welded Age-Hardenable Aluminium Alloy

2020 ◽  
Vol 9 (3) ◽  
pp. 2104-2108
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Aerospace Industry ◽  
Processing Parameters ◽  
Tool Geometry ◽  
High Ductility ◽  
Friction Stir ◽  
Effective Technology

FSW has become the most effective technology in solving problems that have reached the profiled sheets with the continuation of material, particularly in the aerospace industry, with the use of different joining techniques that require high ductility and tensile strength. Current study, FS weldments AA6061-T6 were successfully obtained with varying processing parameters and were mechanically and metallurgically characterized. This paper illustrates macrostructure analysis, influence of tool geometry and process parameters, Fractography analysis microstructure analysis, microhardness of aluminium alloy AA6061-T6.

Robotic Friction Stir Welding of AA5754 Aluminum Alloy Sheets at Different Initial Temper States

2014 ◽  
Vol 622-623 ◽  
pp. 540-547 ◽  
Author(s):  
Massimo Callegari ◽  
Archimede Forcellese ◽  
Matteo Palpacelli ◽  
Michela Simoncini
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Speed ◽  
Process Condition ◽  
Hybrid Structure ◽  
Welding Parameters ◽  
Friction Stir ◽  
Robotic Friction Stir Welding

Robotic friction stir welding experiments were performed on AA5754 aluminium alloy sheets, 2.5 mm in thickness, in two different temper states (H111 and O-annealed). A six axes robot with a hybrid structure, characterised by an arm with parallel kinematics and a roll-pitch-roll wrist with serial kinematics, was used. The effect of the process parameters on the macro-and micro-mechanical properties and microstructure of joints was widely analysed. It was shown that, under the same process condition, the mechanical properties of the joints are strongly influenced by the initial temper state of the alloy. In particular, as AA5754-H111 is welded, the ultimate tensile strength is not significantly affected by the process parameters whilst the ultimate elongation significantly depends on the welding speed. In AA5754-O, both ultimate values of tensile strength and elongation are affected by the welding speed whilst a negligible effect of the rotational speed can be observed. Irrespective of the welding parameters, the H111 temper state leads to mechanical properties higher than those given by the O-annealed state. An investigation has been also carried out in order to evaluate the micro-hardness profiles and microstructure of the FSWed joints in order to understand the mechanisms operating during robotic friction stir welding.

scholarly journals Multi objective optimization of process parameters of AA2014 Friction Stir Weldments using Genetic Algorithm

2020 ◽  
Vol 12 (3) ◽  
pp. 183-193
Author(s):  
L. Suvarna RAJU ◽  
Borigorla VENU ◽  
G. MALLAIAH
Keyword(s):  
Mechanical Properties ◽  
Genetic Algorithm ◽  
Process Parameters ◽  
Welding Speed ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Friction Stir ◽  
Optimization Of Process Parameters ◽  
Tool Tilt Angle ◽  
Tool Pin

The influence of tool pin profile and process parameters on microstructure and mechanical properties of AA2014 weldments was studied. Tool pin profiles such as a Straight Cylindrical Threaded (SCT) and Taper Cylindrical Threaded (TCT) profiles are used for experimentation. The process parameters such as constant tool rotational speed of 900 rpm, welding speed and tool tilt angles at 30, 40, 50, and 60mm/min and 1o, 2o, respectively, are used to fabricate the weldments. A set of experiments was conducted with two different tool pin profiles and mechanical properties were evaluated. The better mechanical properties such as tensile strength of 367N/mm2, impact strength of 10J and hardness of 139HV were obtained by using TCT pin when compared to SCT pin. The observed mechanical properties have been correlated with microstructure. The mechanical properties were analyzed by ANOVA and regression analysis. Objective functions and constraints are developed for the three responses in terms of factors. The factors are optimized using Genetic Algorithm (GA). From the GA results, it is observed that the welding speed of 58mm/min and tool tilt angle of 1.95o are found to be the better combination for carrying out the experiments using TCT pin profile.

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