scholarly journals Shear and Hardness Properties Study of AA-6061 Aluminium Alloy Lap-Joints Produced by Friction Stir Spot Welding Process Using H13 Tool Steel

Author(s):  
Afif Mohamad Hanapiah ◽  
Sumaiya Islam ◽  
Neamul Khandoker ◽  
Mazid Abdul Md

By virtue of high-strength verses weight ratio aluminium alloys are achieving attentions in automobile, marine, and aircraft industries as it reduces the fuel consumption for running the vehicles. But their main drawback is the destruction of their carefully engineered microstructures by high heat generated in traditional welding processes. Friction Stir Welding (FSW) minimizes excessive heat in the welding zone and does not   influence the microstructural features.  FSW is currently one of the recommended solutions for manufacturing aluminium alloy welded machine parts. In this study, AA6061 Al-alloy strips were lap joined using the improvised FSW setup tool clamping it on the spindle of a CNC milling machine with the speed rate varied from 1000 rpm to 3000 rpm, and three different feed rates 5, 15, and 25 mm/min. Shear strength experiments of these joints revealed that samples created with the speed rate of 1000 rpm and feed rate of 25 mm/min performed best showing the highest load carrying capacity of 8976 N with elongation of 1.04%. They also demonstrated highest Vickers hardness value of 31 at the centre of the weldment.

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
T. Sathish ◽  
S. Tharmalingam ◽  
V. Mohanavel ◽  
K. S. Ashraff Ali ◽  
Alagar Karthick ◽  
...  

Aluminium and its alloys play a significant role in engineering material applications due to its low weight ratio and superior corrosion resistance. The welding of aluminium alloy is challenging for the normal conventional arc welding processes. This research tries to resolve those issues by the Tungsten Inert Gas welding process. The TIG welding method is an easy, friendly process to perform welding. The widely applicable wrought aluminium AA8006 alloy, which was not considered for TIG welding in earlier studies, is considered in this investigation. For optimizing the number of experiments, the Taguchi experimental design of L9 orthogonal array type experimental design/plan was employed by considering major influencing process parameters like welding speed, base current, and peak current at three levels. The welded samples are included to investigate mechanical characterizations like surface hardness and strengths for standing tensile and impact loading. The results of the investigation on mechanical characterization of permanent joint of aluminium AA8006 alloy TIG welding were statistically analyzed and discussed. The 3D profilometric images of tensile-tested specimens were investigated, and they suggested optimized process parameters based on the result investigations.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rafał Burek ◽  
Dawid Wydrzyński ◽  
Andrzej Kubit ◽  
Waldemar Łogin

Purpose This paper aims to experimentally determine the influence of the tool shoulder depth value on the structural and strength properties of the single lap joints made of 7075-T6 aluminium alloy made with friction stir welding (FSW) technology. The aim of the preliminary tests is to optimize the parameters of joining process of thin-walled structures such as the skin-stringer joint or skin-frame joint of the aircraft fuselage. The tests were carried out for materials commonly used in such structures, i.e. 1.6 mm thick sheet 7075–T6 aluminium alloy with cladding on both sides (cladding thickness 4% per each side). The layer of clad protects plates from corrosion. Design/methodology/approach This study shows the results of the investigation for the joining of 7075–T6 ALCLAD aluminium alloy sheets. The welding process was carried out on a computer numerical control milling machine SOLARUCE TA–20A. Linear FSW welding was performed using a commercial tool from RSS SCHILLING with the symbol 10–K–4–Z–M–O, which is fabricated of hot work tool steel. Constant parameters of the technological process were applied. The welding process was executed for different values of the shoulder depth ZS. Findings This paper investigated the dependence between the thinning of the welded material and the depth value of the tool shoulder during the FSW process. The influence of the depth value of tool shoulder on joint strength in the static tensile/shear test was also performed. With the increase of the depth of the tool, the size of flash and structures of the face of the joint changes as well (its annular surface resulting from the tool’s work and the accompanying process of material flow on the run-off side). Such conditions in the process require a proper tool depression to reduce the occurrence of flash and minimize material thinning to achieve high joint strength and maintain the conditions for plasticizing the material. Practical implications Based on the experimental tests carried out, a number of guidelines for the correct conduct of the welding process can be outlined. Originality/value Taking into account the various aspects of the process, the optimal range of the tool depth into the material is a value of approximately 0.06 mm. At this value, the face of the weld is not porous; the flash is easily removed; and the strength of the joint and the deformation of contact line are at an acceptable quality level.


2009 ◽  
Vol 83-86 ◽  
pp. 1220-1227
Author(s):  
Gianluca Buffa ◽  
Livan Fratini

Spot welding can be considered a very common joining technique in automotive and transportation industries as it permits to obtain effective lap-joints with short process times and what is more it is easily developed through robots and automated systems. Recently the Friction Stir Spot Welding (FSSW) process has been proposed as a natural evolution of the already known Friction Stir Welding (FSW) process, allowing to obtain sound spot joints that do not suffer from the insurgence of typical welding defects due to the fusion of the base material. In the paper, a modified Friction Stir Spot Welding (FSSW) process, with a spiral circular movement given to the tool after the sinking stage, is proposed. A continuum based numerical model for Friction Stir Spot Welding process is developed, that is 2D Lagrangian implicit, coupled, rigid-viscoplastic. This model is used to investigate the distribution of the main field variables, namely temperature, strain and strain rate, as well as the Zener-Hollomon parameter which, in turn, strongly affects the Continuous Dynamic Recrystallization (CDRX) process that takes place in the weld nugget. Numerical and experimental results are presented showing the effects of the process parameters on the joint performances and the mechanical effectiveness of the modified process.


Author(s):  
Boddu Rajnaveen ◽  
Govada Rambabu ◽  
Kollabothina Prakash ◽  
Kotipalli Srinivasa Rao

Abstract AA2219-T87 aluminium alloy has been used in aerospace applications because of its high strength, low density and resistance to corrosion. The copper in the alloy improves the hardness and lowers melting point, which makes two sections easily joined with a process called friction stir welding of aluminium alloy. In the present work, heat-treated AA2219 alloy was butt welded by solid-state friction stir welding process. This work aims to develop a suitable combination of welding parameters for producing defect-free weld joints of AA2219 alloy to improve tensile and corrosion properties. The most influencing control parameter for optimising the friction stir welding responses was determined using sophisticated design of experiments (DOE) techniques. Ultimate tensile strength and corrosion resistance are observed as responses in this study. To achieve the desired weld responses, a three-factor, three-level Box-behneken design was used. Analysis of Variance (ANOVA) was carried out to examine the interaction effect and significant welding parameter to set the optimal level of welding conditions. Multi-response regression equations have been developed using response surface methodology (RSM) to estimate the output characteristics of weld. The Genetic algorithm (GA) was used to optimise the predicted mathematical model under given optimization constraints. The results shown that the optimum responses are obtained at input factors rotational speed 300 rpm, welding speed 80 mm/min, and axial force of 10kN.


Author(s):  
Nisith Goswami ◽  
Kamal Pal

The thermoplastic polymers and precipitation hardened aluminium alloys are highly popular in the aerospace and automobile sectors as a replacement of metallic materials to improve the strength to weight ratio. Thus, the unlike aluminium alloy to polycarbonate assembled structures are often necessary for which mechanical fastening and adhesive bonding are the primary methods for joining as fusion welding processes are inadequate. However, the dissimilar joint efficiency is found to be less. Thus, the ultrasonic and friction welding processes are developed. The friction stir welding is one such advanced material stirring technique without any melting of base materials. The present work addresses metallic aluminium (Al6061) to polycarbonate sheet materials joining using friction stir welding in overlap configuration using tapered H13 tool steel. The thrust force with associated tool stirring torque has been acquired in real time during plunging followed by welding phase. The weld bead profile with respective force-torque signals was analysed for the process monitoring. The tensile test has been carried out on the lap welds. The weld interface of the unlike sheets have also been scrutinised. Initially, the aluminium sheet was partially overlapped on polycarbonate for the parametric study. The highest joint efficiency was found to be 40.2% at 1400 rpm tool rotational speed and 75 mm/min traverse speed due to improper material mixing at the weld interface. Therefore, the feasibility of the process have been tested by placing thermoplastic polycarbonate over aluminium alloy through which the joint efficiency was further improved (48.57%) at comparatively low tool rotational speed (1100 rpm) with lower welding speed (55 mm/min) as the minute metallic particles uniformly mixed with melted and solidified polycarbonate due to more uniform torque in the welding phase. The tool stirring torque and axial thrust was found to be higher in this overlap position.


Author(s):  
R.V. Vignesh ◽  
R. Padmanaban

Aluminium alloy AA1100 finds application in light weight structures due to its high strength to weight ratio. Friction stir welding is a solid state welding process, in which the materials are joined in the plasticized state. The quality of the friction stir welded joints depends on the process parameters used and tool parameters. In this study, four process parameters were varied at five levels and experimental trials were performed as per face centered central composite design. Artificial neural network model was developed with cascade forward propagation network architecture and trained with LM algorithm and BFGS QN algorithm. The models were used to predict the tensile strength of the joints and the error in prediction was used to judge the accuracy of the developed models. It is observed that BFGS QN algorithm trains the ANN efficiently and results in accurate predictions.


2015 ◽  
Vol 766-767 ◽  
pp. 712-720
Author(s):  
G. Britto Joseph ◽  
G. Murugesan ◽  
R. Prabhaharan ◽  
Tariq Mohammad Choudhury

Aluminium alloys are widely used in automotive, aerospace and ship industries as high strength-to-weight ratio materials. With the increasing demand for lightweight components, their application is becoming more extensive. To study the effect of Tool geometries on Metallurgical & mechanical properties of Aluminum alloy 5052 H32 using friction stir welding process. To briefly discuss about the conditions & conclude the suitable condition for Aluminium alloy 5052 H32. To plot and conclude the hardness values for various conditions. The tool material Mild Steel IS 2062 FE410 cone type and thread type has been selected for this research for various speeds to find suitable condition. The micro structure and macro structure have checking the structural formation of welded area in details to know it the strength of the joining. The present friction stir welding research is implementing the new tools for the current issues; here we try to implement new material for already available tools.


2010 ◽  
Vol 638-642 ◽  
pp. 1209-1214 ◽  
Author(s):  
Marie Noëlle Avettand-Fènoël ◽  
Roland Taillard ◽  
Christophe Herbelot ◽  
Abdellatif Imad

Friction stir welding (FSW) is a quite recent welding method which takes advantage of being performed in the solid state. Compared with the usual welding processes, it therefore presents many benefits such as a lower heat-input, a reduction of residual stresses and an elimination of the solidification defects etc.. Up to now, it has essentially been applied to aluminium alloys and far more recently to a small number of bimaterials. The present study deals with three kinds of beads between pure copper and a 6082 aluminium alloy. Both materials were butt joined by FSW. The welds differ by the location of the tool which was placed either at the interface between the two metals or on the copper or the 6082 side of this surface. Their structure was characterized at a multi-scale level by using a number of techniques. Tensile and microhardness tests were also performed. The tool place is shown to govern the microstructure and the ensuing mechanical behaviour of the weld. Its influence on the plastic flow with its repercussions on i) welding defects and ii) mechanical properties is going to be demonstrated. Some ways of improvement of the welding process will finally be suggested.


2017 ◽  
Vol 37 (1) ◽  
pp. 6-21 ◽  
Author(s):  
C. Rajendrana ◽  
K. Srinivasan ◽  
V. Balasubramanian ◽  
H. Balaji ◽  
P. Selvaraj

AbstractAA2014 aluminum alloy (Al-Cu alloy) has been widely utilized in fabrication of lightweight structures like aircraft structures, demanding high strength to weight ratio and good corrosion resistance. The fusion welding of these alloys will lead to solidification problems such as hot cracking. Friction stir welding is a new solid state welding process, in which the material being welded does not melt and recast. Lot of research works have been carried out by many researchers to optimize process parameters and establish empirical relationships to predict tensile strength of friction stir welded butt joints of aluminum alloys. However, very few investigations have been carried out on friction stir welded lap joints of aluminum alloys. Hence, in this investigation, an attempt has been made to optimize friction stir lap welding (FSLW) parameters to attain maximum tensile strength using statistical tools such as design of experiment (DoE), analysis of variance (ANOVA), response graph and contour plots. By this method, it is found that maximum tensile shear fracture load of 12.76 kN can be achieved if a joint is made using tool rotational speed of 900 rpm, welding speed of 110 mm/min, tool shoulder diameter of 12 mm and tool tilt angle of 1.5°.


2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.


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