scholarly journals Novel Technique for Enhancing the Strength of Friction Stir Spot Welds through Dynamic Welding Parameters

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 280
Author(s):  
Ahmed Badwelan ◽  
Ali M. Al-Samhan ◽  
Saqib Anwar ◽  
Lotfi Hidri

Presently, friction stir spot welding (FSSW) has become a common alternative for spot welding technologies. Over the years, researchers have implemented various methods for enhancing weld strength. However, the literature shows that the previously reported approaches have used static (constant) welding parameters set at the beginning of the welding stroke (i.e., the FSSW parameters were kept constant during the welding stroke). In contrast, in this study, an innovative technique is proposed for enhancing the weld strength for Al 1050 material by adjusting the FSSW process parameters during the welding stroke. Two FSSW parameters, namely, feed rate and spindle speed (dynamic parameters), are used in this study with a stepwise variation function and are changed during the welding stroke. The results of this study show that the weld tensile strength is enhanced by 12–21% when using the proposed novel dynamic welding parameter technique. This is a significant increase in the weld strength compared to when static welding parameters are employed during the welding stroke.

2021 ◽  
pp. 009524432110015
Author(s):  
Mustafa Kemal Bilici

In this study, two different polymer materials were used. In the joints made with friction stir spot welding, firstly (PP/PP and HDPE/HDPE) and then different materials (PP/HDPE, HDPE/PP) joining processes were carried. The influence of the tool rotational speed and the stirring time on joint formation and weld strength were determined. The temperature of the liquid welding materials varies according to the materials to be combined. High weld strengths were obtained at the friction stir spot welding of similar plastic sheets. The highest weld strengths were obtained in PP-PP welds. Low weld strengths were obtained at the friction stir spot welding of dissimilar plastic sheets because of immiscible and incompatible blends formed during the welding operation. The lowest weld strengths were obtained in PP-HDPE welds. The chemical composition and the phase morphology of the blends, the mechanical scission occurrence and the welding residual stresses determine the strength of the welds.


2014 ◽  
Vol 493 ◽  
pp. 739-742 ◽  
Author(s):  
Ario Sunar Baskoro ◽  
Suwarsono ◽  
Gandjar Kiswanto ◽  
Winarto

Technology of Friction Stir Welding (FSW) is a relatively new technique for joining metal. In some cases on Aluminum joining, FSW gives better results compared with the arc welding processes, including the quality of welds and less distortion. The purpose of this study is to analyze the parameters effect of high speed tool rotation onmicro Friction Stir Spot Welding(μFSSW) to theshear strengthof welds. In this case, Aluminum material A1100, with thickness of 0.4 mm was used. Tool material of HSS material was shaped with micro grinding process. The spindle speed was fixed at 30000 rpm. Tool shoulder diameter was 3 mm, and a length of pin was 0.7 mm. The parameter variations used in this study were the variable of pin diameter (1.5 mm, 2.0 mm, and 2.5 mm), a variable ofplunge speed(2 mm/min, 4 mm/min, 6 mm/min), and the variable ofdwell time(2 seconds, 4 seconds, 6 seconds). Where the variation of these parameters will affect to the mechanical properties of welds (as response) was theshear strength.Response Surface Methods(RSM) was used to analyze μFSSW parameters with theshear strengthof welds. From the result of experiment and analysis, it is shown that the important welding parameters in high speed μFSSW process are pin diameter and plunge speed.


2016 ◽  
Vol 860 ◽  
pp. 49-52 ◽  
Author(s):  
Munir Tasdemir ◽  
Mustafa Kemal Bilici ◽  
Mehmet Kurt

In the present study, we attempt to use powder of glass spheres filler and reinforce material in HDPE to produce composite structure and then evaluate its mechanical properties to study the effect of welding parameters and filler content on mechanical properties of HDPE. The effect of welding parameters (tool rotational speed, the plunge depth and the dwell time) on friction stir spot welding properties of high density polyethylene/glass spheres (hollow) polymer composites sheets was studied.


2020 ◽  
Vol 835 ◽  
pp. 274-287
Author(s):  
Mahmoud Hussin Fahmy ◽  
Hamed A. Abdel-Aleem ◽  
Nahid Ahmed Abdel-Elraheem ◽  
M.R. El-Kousy

The quality of welded joints of FSSW is mainly dependent on the processing parameters while the main disadvantage of this process is the creation of an exit hole. Process parameters, namely tool dimensions, tool rotational speed, and stir time were changed and their impact on bond dimensions and weld strength was investigated using 2024-T3 Al Alloy. Macro- and microstructures of the welded samples were examined; shear fracture loads were measured and the optimum set of operation variables was determined. To decrease the exit hole of the first stage the present paper proposes a modified two-stage weld-refill process employing the same welding machine. In this work, this two-stage process was referred to as reversed friction stir spot welding (ReFSSW). In the second stage, a smaller pin was used and the shoulder diameter was designed such that to force the metal of the upper plate to flow towards the exit hole of the first stage decreasing its dimensions. The metal flow in the second stage was evaluated by examining the microstructure of the metal that filled the exit hole of the first stage. Thin stir zone was found around the pin of the second stage followed by thermomechanically affected zone consisting of grains elongated in the vertical direction. The proposed process resulted in smaller exit hole dimensions and consequently higher mechanical properties compared with the conventional single-stage FSSW.


2018 ◽  
Vol 917 ◽  
pp. 246-251
Author(s):  
Kai Xu ◽  
Shu Quan Zhang

A lap welding experiment of DP590 steel and 6061 aluminum plate is carried out by using Heating Friction Stir Spot Welding (HFSSW) to study the influence of welding parameters on the forming quality. The results show that a lap joint with better forming can be obtained for the dissimilar metal of steel and aluminum. Under the condition that the rotating speed of the stirring tool is 1000r/min, the penetration depth, 0.2mm, the dwell time, 90s, the welding pressure, 0.2Mp, and the flow rate of cooling air, 20L/min, the forming quality of the surface of the joint line is good & bright, and the exit hole is also smaller. The mechanism of heat production is revealed in the following: the main heat is produced by the friction between the stirring tool shoulder and the welded part & between the probe and the welded part as well as by the latent heat resulted from the plastic deformation of the material in joint line during welding.


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