The Effect of Top Surface Lubrication on the Friction Stir Welding of Polycarbonate Sheets

2021 ◽  
Vol 36 (1) ◽  
pp. 94-102
Author(s):  
M. M. Z. Ahmed ◽  
A. Elnaml ◽  
M. Shazly ◽  
M. M. El-Sayed Seleman

Abstract In this work, top surface lubrication during friction stir welding of polycarbonate sheets was applied. A homogenous layer of Paraffin wax has been placed on the top surface of the joint area with a width that ensures to cover the shoulder diameter. Then FSW was applied using conventional FSW tool with rotating pin and shoulder at different FSW parameters (Rotation speeds of 1 000, 1500, 2 000 min–1 and welding speeds of 25, 50, 75,100 mm/min). The main objective of using the wax is to act as a lubricant that reduces the friction between the shoulder and the polycarbonate surface. The joints produced were investigated in terms of surface quality, internal defects, and mechanical properties. During FSW the wax is melted and played as lubricant between the tool shoulder and the polycarbonate surface and resulted in defect-free surface with no thickness reduction of the original plate. The transverse cross-section showed defect-free joints for the majority of the FSW parameters investigated. Tensile testing results showed a reduction of the tensile strength after FSW, and an enhancement in the tensile strength with the increase of welding speed or rotation speed. The fracture occurs at the joint zone and the fracture surface investigation using SEM showed the existence of spherulitic structure in the weld joint.

2011 ◽  
Vol 110-116 ◽  
pp. 3165-3170 ◽  
Author(s):  
Ghodratollah Roudini ◽  
Sajad Gholami Shiri ◽  
Masoud Mohammadi Rahvard

there are some parameters in friction stir welding (FSW) technique such as tool design, tool rotation speed and tool travel which can be controlled in a precise manner thus controlling the energy input into the system. In this study the effects of these parameters were investigated on microstructure and tensile strength of 5052 aluminum alloy. Roll sheets of this alloy were welded by FSW method at different rotation speeds (400, 800, 1600 and 2500 rpm), welding speeds (50 and 100 mm/min) and tools shoulder diameters (14 and 20 mm). The microstructure results showed that the stir zone (SZ) and thermo-mechanically affected zone (TMAZ) had dynamically recrystallized and recovered respectively. Also the tensile strength of samples welded at tool rotation speeds of 400 and 800 rpm, travel speed 50 mm/min and tools shoulder diameter of 20 mm is similar to that of base metal. The tool rotation speeds of 400 rpm have a good welding ability with higher travel speed and lower tools shoulder diameter.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 330
Author(s):  
Mohamed M. Z. Ahmed ◽  
Nabil Jouini ◽  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
Mohammad Jhaheen

This study investigated the effect of the friction stir welding rotation rate and welding speed on the quality and properties of the dissimilar joints between aluminum and carbon steel. Plates of 4 mm thickness from both AA2024 and AISI 1018 were successfully friction stir butt welded at rotation speeds of 200, 250, and 300 rpm and welding speeds of 25, 50, and 75 mm/min. The joint quality was investigated along the top surface and the transverse cross-sections. Further investigation using scanning electron microscopy was conducted to assess the intermetallic layers and the grain refining in the stir zone. The mechanical properties were investigated using tensile testing for two samples for each weld that wire cut perpendicular to the welding direction and the hardness profiles were obtained along the transverse cross-section. Both the top surface and the transverse cross-section macrographs indicated defect free joints at a rotation rate of 250 rpm with the different welding speeds. The intermetallic compounds (IMCs) formation was significantly affected by the heat input, where there is no formation of IMCs at the Al/steel interfaces when higher traverse speed (75 mm/min) or lower rotation speed (200 rpm) were used, which gave the maximum tensile strength of about 230 MPa at the low rotation speed (200 rpm) along with 3.2% elongation. This is attributed to the low amount of heat input (22.32 J/mm) experienced. At the low traverse speed (25 mm/min and 250 rpm), a continuous layer of Al-rich IMCs FeAl3 is formed at the joint interface due to the high heat input experienced (79.5 J/mm). The formation of the IMCs facilitates fracture and reduced the tensile strength of the joint to about 98 MPa. The fracture mechanism was found to be of mixed mode and characterized by a cleavage pattern and dimples. The hardness profiles indicated a reduction in the hardness at the aluminum side and an increase at the steel side.


2015 ◽  
Vol 813-814 ◽  
pp. 462-466 ◽  
Author(s):  
R Padmanaban ◽  
V. Muthukumaran ◽  
A. Vighnesh

Friction stir welding (FSW) has become a potential solid state joining technique with considerable advantages over conventional joining process. Defect-free friction stir welded joints with high joint strength are obtained when optimum process parameters are used. Although a large number of parameters govern the FSW process, the tool rotation speed, Welding speed and tool geometry are key parameters that influence the joint strength. In this work, a statistical model relating process parameters and the tensile strength (TS) of friction stir welded AA1100 joints is build using response surface methodology. The four independent variables are tool rotational speed (TRS), welding speed (WS), shoulder diameter (SD) and pin diameter (PD). Central Composite design is used and Analysis of Variance at 95% confidence level was applied to assess the adequacy of the developed model. Genetic algorithm is used for optimizing the parameters. The optimum process parameter values predicted using the genetic algorithm are as follows. Tool rotation speed: 1001.9 rpm; welding speed: 62 mm/min; shoulder diameter: 17.8 mm and pin diameter: 6.5 mm. The corresponding tensile strength of the joints is 73.1556 MPa


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.


2019 ◽  
Vol 969 ◽  
pp. 828-833 ◽  
Author(s):  
R. Nandhini ◽  
R. Dinesh Kumar ◽  
S. Muthukumaran ◽  
S. Kumaran

The friction stir welding of polyamide 66 with a specially modified tool is studied. A variation of the conventional friction stir welding is investigated by incorporating a friction plate for the purpose of heating the polymer in the course of welding process through the tool shoulder. This in turn, improves the efficiency of the weld. The association of the welding process parameters and the weld performance has been investigated by the grey relational analysis with multi response characteristics like weld tensile strength, percent elongation and hardness. Macrostructure of the weld joint cross section has been explored by Stereo microscope. The maximum weld tensile strength of 63 MPa and a Shore hardness of 60 D at the weld nugget are obtained. The hardness profiles of the welded samples have been analyzed in this investigation.


2018 ◽  
Vol 7 (3.34) ◽  
pp. 366
Author(s):  
Mariyappan. K ◽  
Praveen K ◽  
Suresh Kumar.S ◽  
Kadambanathan. K ◽  
Rajamanickam. S ◽  
...  

The aim of this study is to show the feasibility for butt joining dissimilar brass to austenitic stainless steel plates by Friction Stir Welding. In this study, the limited FSW parameters were employed. Metallurgical characterization like Scanning Electron Microscopy and Mechanical characterization like tensile test, Micro hardness is done to investigate the joint performance and the weld zone of dissimilar brass/steel joints. The tensile strength and micro hardness values are 20 MPa, 122 MPa and 157 MPa and 175 Hv, 196 Hv and 199 Hv for the table traverse speeds of 40 mm/min, 50 mm/min and 60 mm/min respectively. The tensile strength of dissimilar brass/steel joint was found to be lower than that of parent metals. The defect free brass/steel interfaces were seen by Scanning Electron Microscopy. It was illustrated that the stirred zone exposed to two main structures namely, recrystallized grains of brass and intercalated swirl and vortex-like structure which can be characterized both the recrystallized brass grains and steel layers. This work is one of the preliminary studies on the detailed examinations of the dissimilar brass/steel joined by Friction stir welding. 


Author(s):  
Mohd Atif Wahid ◽  
Zahid A Khan ◽  
Arshad Noor Siddiquee ◽  
Rohit Shandley ◽  
Nidhi Sharma

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.


2016 ◽  
Vol 27 (1) ◽  
pp. 9-17
Author(s):  
Maryati Maryati ◽  
Bambang Soegijono ◽  
M Yudi Masduky ◽  
Tarmizi Tarmizi

Friction Stir Welding (FSW) is a new method of welding process which is affordable and provide good quality. Aluminium 5083-7075 has been connected successfully by using friction stir welding (FSW) method into butt joint connection form. Tool rotation speed is one of the important parameters in FSW. The changes of rotation speed will affect the characteristics of mechanical properties and microstructure. The parameters of welding being used are welding speed of 29 mm/minutes by varying the speed rotation of 525 rpm, 680 rpm, 910 rpm, and 1555 rpm. In order to find out the mechanical strength of welds, tensile strength and hardness testing is done while finding out the microstructure will be done by using optical microscope and Scanning Electron Microscope (SEM). The result of the research showed that the highest tensile strength obtained at 910 rpm speed rotation about 244.85 MPa and the greatest hardness values was found on aluminium 5083 around the wheel zone area about 96 HV with rotary speed of 525 rpm. Then, the result of testing the macro and microstructure on all samples indicated defect which is seen as incomplete fusion and penetration causing the formation of onion rings. In other words, it is which showed that the result of stirring and tacking in the welding area is less than perfect.


2020 ◽  
Vol 1157 ◽  
pp. 38-46
Author(s):  
Victor Verbiţchi ◽  
Radu Cojocaru ◽  
Lia Nicoleta Boțilă ◽  
Cristian Ciucă ◽  
Ion Aurel Perianu

Experiments have been performed for the butt welding of 160 mm x 90 mm x 2 mm sheets of EN AW 5754 aluminium alloy, where the friction stir welding (FSW) has been used.Referring to the parent metal, the chemical composition and the form of wrought products of the aluminium alloy EN AW 5754 is presented, according to the standard EN 573-1:2005, respectively EN 573-3:2013. The mechanical properties of EN AW-5754 (Al Mg3) sheets are presented, according to EN 485-2:2016. The experiments have been conducted on the own equipment for friction stir welding, type FSW-4kW-10kN, to execute 8 (eight) FSW test pieces, according to EN ISO 25239-4. A quenched FSW tool, own-made of C 45 grade steel, EN 10083, has been used. The parameters of the FSW tests are shown. As main parameters, the rotational speed of the FSW tool was in the range n = 800 – 1200 rev/min, respectively the travel speed was in the range v = 50 – 200 mm/min. The run of the joining experiments is described and the joining test pieces are presented in figures. The ultimate tensile strength of the parent metal (σmin,pm) is based on the specified minimum tensile strength of the ”O” condition of the parent material, respectively this value is also required for the weld, that is σmin,w = 190 MPa. The specimens T1.0, T1.1, T2.1, T2.2, T3.1, T3.2, T4.1, T4.2, T5.1, T5.2 și T6.1 are adequate and accepted by this tensile test. The specimens T1.2, T6.2, T7.1, T72. and T8.1 can be accepted, if higher properties are achieved with a full postweld treatment. Another possibility is a lower extent of the minimum tensile strength of the weld that shall be in accordance with another design specification, for example σmin,w = 145 MPa. By the correlation of the FSW parameters with the results of the tensile test, the ranges for the main parameters with adequate values of the ultimate tensile strength are established: n = 800 – 1000 rev/min and v = 50 – 100 mm/min. By the conclusions, the main aspects of the execution of the FSW test pieces, as well as the results of the tensile tests are selected. The involved industrial areas of the applications are: electro-technique, electronics, manufacturing, shipbuilding and automotive industries. The FSW process is ecological, because it neither uses, nor produces hazardous substances. The references consist of 12 titles.


2019 ◽  
Vol 969 ◽  
pp. 589-594
Author(s):  
R. Dinesh Kumar ◽  
D. Srija ◽  
P. Suresh ◽  
S. Muthukumaran

The aluminium alloys AA2024 and AA6061 are widely used for fabricating light weight structural member with better strength and corrosion resistance. Friction stir welding (FSW) parameters such as rotational speed, tool shoulder profile and traverse speed are used to identify the corrosion resistance and microstructural analysis in different weld region of AA2024-AA6061 dissimilar joints. In this work, Taguchi L9 orthogonal array with three variables and three stages has been used to reduce the number of experiments. Potentiodynamic polarization (PDP) testing results are optimized by ANOVA technique and obtain the corrosion rate as 5.72 mil/yr and resistance polarization as 835.28 ohm.cm2. The optimal parameter set is found to be 1000 rpm, flat shoulder and 45 mm/min. The microstructural analysis reveals localized pit dissolution in the nugget zoneThe aluminium alloys AA2024 and AA6061 are widely used for fabricating light weight structural member with better strength and corrosion resistance. Friction stir welding (FSW) parameters such as rotational speed, tool shoulder profile and traverse speed are used to identify the corrosion resistance and microstructural analysis in different weld region of AA2024-AA6061 dissimilar joints. In this work, Taguchi L9 orthogonal array with three variables and three stages has been used to reduce the number of experiments. Potentiodynamic polarization (PDP) testing results are optimized by ANOVA technique and obtain the corrosion rate as 5.72 mil/yr and resistance polarization as 835.28 ohm.cm2. The optimal parameter set is found to be 1000 rpm, flat shoulder and 45 mm/min. The microstructural analysis reveals localized pit dissolution in the nugget zone.


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