scholarly journals Parametric optimization of friction stir welding of Al-Mg-Si alloy: A case study

Author(s):  
Nasir Khan ◽  
Sandeep Rathee ◽  
Manu Srivastav

Al-Mg-Si alloys have wide applications in industries such as aerospace, marine, automobile, construction. In this work, newly developed friction stir welding (FSW) was utilized for joining of AA6082-T6 alloy. The effect of major FSW process variables like rotational speed, traverse speed, and shoulder diameter of tool is studied over microstructural and mechanical characteristics of friction stir welded (FSWed) joints. Experimental design was done using Taguchi method (L9 orthogonal array). Three factors viz. rotational speed, welding speed, and diameter of tool shoulder were taken at three levels each. Mathematical modelling was developed in order to optimize the tensile strength of weld joints. Analysis of variance (ANOVA) was utilized to determine the percentage contribution of input variables. The results of present study exhibits that shoulder diameter, rotation, and welding speed of tool significantly affect the mechanical strength of FSWed joints.

Author(s):  
Umesh Kumar Singh ◽  
Avanish Kumar Dubey

Lightweight with excellent strength of magnesium alloys has attracted its use in transportation industries but difficulty in fusion welding of magnesium alloys restricts its application. The present research investigates solid state friction stir welding of dissimilar AZ31-AZ91 magnesium alloys with aim to achieve optimum quality welds. Surface roughness, microstructure and mechanical properties of these joints have been investigated at different tool rotational speed, welding speed and tool shoulder diameter. Maximum joint strength obtained is 89.71% (as compare to AZ31) which is more than the previously reported joint strengths of dissimilar magnesium alloys. Further, mathematical relations for responses have been developed and utilised for multi-objective optimization using teaching-learning-based optimization algorithm. Eventually, teaching-learning-based optimization algorithm results suggest that the optimum value of surface roughness (3.3925 µm), grain size (12.6869 µm), tensile strength (237.9621 MPa), microhardness (69.3652 Hv) and flexural strength (333.2285 MPa) can be achieved at 921 rpm rotational speed, 30 mm/min welding speed and 15 mm shoulder diameter with overall improvement in multiple responses.


Author(s):  
Arshad Noor Siddiquee ◽  
Sunil Pandey ◽  
Mustufa Haider Abidi ◽  
Abdulrahman Al-Ahmari ◽  
Noor Zaman Khan ◽  
...  

Welding AISI 304 stainless steel is challenging, especially as fusion-based welding processes (such as arc welding) severely undermine the material's corrosion resistance due to sensitization. Solid-state friction stir welding is one of the most suitable alternatives. Friction stir welding of high-strength high-softening materials such as AISI 304 is difficult mainly because of the non-availability of affordable tools and tool life. In this study, AISI 304 stainless steel was successfully butt-welded by friction stir welding. The experiments were performed using Taguchi's L27 orthogonal array. Shoulder diameter, tool r/min, and traverse speed were selected as the most influential welding parameters. A Tungsten Carbide (WC) tool was employed with a tapered pin profile. Defect-free joints were fabricated successfully for all the welding conditions. Microstructural examinations using optical microscopy and scanning electron microscopy revealed significant grain refinement in the stir zone and the presence of distinct structural features such as stepped, dual, and ditch in various characteristics zones. The presence of precipitates was also observed in samples and was confirmed via energy-dispersive X-ray spectroscopy analysis. The in-process traverse force was measured by a special arrangement of force measuring units attached to the work fixture. The traverse force data were analyzed and optimized. The results of an analysis of variance reveal that the traverse speed was the most important parameter, followed by tool r/min, interaction between the tool shoulder diameter and traverse speed, interaction between the tool shoulder diameter and tool r/min, and, finally, the tool r/min.


Author(s):  
Gurunath V Shinde ◽  
Rachayya R Arakerimath

In current research work, an attempt has been made to join dissimilar metals by employing friction stir welding (FSW), i.e., AA3003-H12 (aluminium alloy) and C12200-H01 (copper alloy). The experiments are designed as per full factorial design at different process parameters, namely tool pin profiles, rotational speed, welding speed, and shoulder diameter while the ultimate tensile strength (UTS), yield strength (YS), and percentage elongation (% E) are considered as a performance parameter. Moreover, a statistical tool, i.e., analysis of variance (ANOVA) is also utilized to check the adequacy of the results. It is observed that the higher UTS, % E and YS are obtained by employing a taper pin profile tool at a rotational speed of 1800 rpm, a welding speed of 16 mm/min, and a shoulder diameter of 22.5 mm. The ANOVA results showed that the rotational speed is the most significant factor for current research work. In addition, a scanning electron microscope is utilized for microstructural analysis of welded joints. It is witnessed that the minimum grain size, i.e., 4 microns, is obtained for highest strength specimen and the maximum grain size is obtained for the lowest strength specimen i.e., 31 microns. Besides this, the swirling of cu particle is also observed from advancing side (AS) to the retreating side (RS). Moreover, energy-dispersive X-ray spectroscopy (EDS) indicates the formation of intermetallic compounds i.e. Al2Cu, Al9Cu4 at nugget zone (NZ). The hardness is found to be higher at NZ due to the presence of Al-Cu intermetallic.


Author(s):  
Shubham Verma ◽  
Joy Prakash Misra ◽  
Meenu Gupta

The present study deals with the application of sequential procedure (i.e. steepest ascent) to obtain the optimum values of process parameters for conducting friction stir welding (FSW) experiments. A vertical milling machine is modified by fabricating fixture and tool ( H13 material) for performing FSW operation to join AA7039 plates. The steepest ascent technique is employed to design the experiments at different rotational speed, welding speed, and tilt angle. The ultimate tensile strength is considered as a performance characteristic for deciding the optimal levels. The mechanical and metallurgical characteristics of the joints are studied by executing tensile and microhardness tests. It is concluded from the graphical analysis of the steepest ascent technique that the optimal maximum and minimum values are 1812–1325 r/min for rotational speed, 43–26 mm/min for welding speed, and 2°–1.3° for tilt angle, respectively. Besides, optical microscope and scanning electron microscope are utilized for microstructural and fractographic analyses for a better understanding of the process.


2021 ◽  
pp. 009524432110200
Author(s):  
Ali Ghorbankhan ◽  
Mohammad Reza Nakhaei ◽  
Ghasem Naderi

The friction stir process (FSP) method used to prepare polyamide 6 (PA6)/nitrile-butadiene rubber (NBR) nanocomposites with 1 wt% Graphene nanoparticles. Response surface methodology (RSM) and Box-Behnken design were used to study the effects of four input variables including tool rotational speed (ω), shoulder temperature (T), traverse speed (S), and the number of passes (N) on tensile strength and impact strength of PA6/NBR/Graphene nanocomposite. In order to investigate the dispersion state of Graphene and the morphology of the PA6/NBR blend in the presence of Graphene, wide x-ray patterns (WAX), scanning electron microscopy (SEM) were performed. Furthermore and differential scanning calorimetric (DSC) was used to investigate the thermal properties of PA6/NBR containing 1 wt% Graphene nanoparticles. The results confirmed that at the optimum range of input variables, PA6/NBR/Graphene nanocomposite provided good thermal stability as well as the highest tensile strength, and impact strength. This is caused by the large surface area to volume ratio of the dispersed layered Graphene in PA6/NBR blends. Under optimal conditions of the rotational speed of 1200 rpm, traverse speed of 20 mm/min, shoulder temperature of 125°C, and number pass of 3, the maximum tensile strength and impact strength are 70.4 MPa and 70.3 J/m, respectively.


2014 ◽  
Vol 984-985 ◽  
pp. 586-591 ◽  
Author(s):  
R. Ashok Kumar ◽  
M.R. Thansekhar

— For fabricating light weight structures, it requires high strength-to weight ratio. AA6061 aluminium alloy is widely used in the fabrication of light weight structures. A356 aluminium alloy has wide spread application in aerospace industries. Friction stir welding is solid state joining process which is conducting for joining similar and dissimilar materials. The friction stir welding parameters play an important role for deciding the strength of welded joints. In this investigation, A356 and AA6061 alloys were friction stir welded by varying triangular, square, hexagonal pin profiles of tool keeping the remaining parameters same and AA6061 alloys were friction stir welded by varying tool shoulder diameter as 12mm,15mm,18mm without changing other parameters. Tensile properties of each joint have been analyzed microscopically. From the experimental results, it is observed that hexagonal pin profiled tool and 15mm shoulder diameter tool provides higher tensile properties when compared to other tools.


2011 ◽  
Vol 295-297 ◽  
pp. 1929-1932
Author(s):  
Yi Min Tu ◽  
Ran Feng Qiu ◽  
Hong Xin Shi ◽  
Xin Zhang ◽  
Ke Ke Zhang

In order to obtain better understanding of the friction stir weldability of the magnesium alloy and provide some foundational information for improving mechanical properties of retardant magnesium alloy joints. A retardant magnesium alloy was weld using the method of friction stir welding. The influence of welding parameters on the strength of the joint was investigated. The maximum strength of 230 MPa was obtained from the joint welded at the tool rotational speed of 1000 r/min and welding speed of 750 mm/min.


2020 ◽  
Vol 17 (4) ◽  
pp. 491-507 ◽  
Author(s):  
Nitin Panaskar ◽  
Ravi Prakash Terkar

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.


2013 ◽  
Vol 446-447 ◽  
pp. 301-305
Author(s):  
Mukesh Kumar ◽  
Satish V. Kailas ◽  
R. Ganesh Narayanan

In the present work, the influence of shoulder diameter, traverse speed, and rotational speed on the formability of friction stir welded sheets made between sheets of AA6061T6 and AA5052H32 Al alloys has been studied. In-Plane Plane-Strain formability tests are conducted for this purpose. It is understood from the results that the formability of welded sheets can be improved by optimizing the welding and tool parameters. A larger shoulder diameter, higher traverse speed, and lower rotational speed are favorable for improved formability, and strain hardening exponent of weld region. This is due to the fact that the heat input and subsequent microstructure evolved depends on the heat input, which depends on the welding parameters.


2017 ◽  
Vol 867 ◽  
pp. 97-104 ◽  
Author(s):  
T. Ganapathy ◽  
K. Lenin ◽  
K. Pannerselvam

This paper deals with the effective application of friction stir welding similar to butt joining technique.AL6063 T-6 alloys prepared in 125x 100 x 7mm thickness plate and FSW tool setup were H13 of diameter 25mm rotary tool with straight cylindrical pin profile. The maximum strength was considered for selection of combined process parameter. The process parameters were optimized using Taguchi method. The Rotational speed, welding speed, and axial speed are the main process parameter which taken into our consideration. The optimum process parameters are determined with reference to tensile strength of the joint. From the experiments, it was found the effects of welding parameter are the axial force is highest substantial parameter to determining the tensile strength of the joint. The paper which revealed the optimal values of process parameter are to acquire a maximum tensile strength of friction stir welded AL6063-T6 plates is 101.6Mpa with the combination level of rotational speed, welding speed and axial force are found to be 1100 RPM, 60 mm/min and 12.5 KN. validation test was carried out and results were nearer to the optimized results confirmed by the optimum results.


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