Optimization of friction stir spot welding process parameters for Al-Cu dissimilar joints using the energy of the vibration signals (original) (raw)
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International Journal of Research in Engineering and Innovation , 2020
Identification of process parameters and their effects to the outcomes of the system using experimental method could be time consuming, daunting and costly course. Using proper statical methods, i.e. response surface methodology (RSM) could significantly reduce the number of required experiments and statistical significant of the process parameters can be identified. Friction stir welding (FSW) is one of those welding techniques with various parameters which have different effects on the quality of the welds. In FSW the tool rotational speed (TRS) and traverse speed (TS) influence the mechanical properties of the fusion zone. In this work, the effect of tool rotational speed, traverse speed and tilt angle on mechanical properties of friction stir welded joint of AA2024 and AA5052 have been investigated. There are 20 experiments were performed as per center composite design (CCD) approach of RSM. The tensile test were carried out to observe tensile strength and percentage elongation of FSWed joints. The quadratic regression mathematical model was developed to establish a relation between inputs and outputs. ANOVA was used to ensure the significance of the process parameters and their interactions. An optimized combination of process parameters was determined using grey relation coupled with principal component analysis, a hybrid approach.
Determining Optimum Shear Strength of Friction Stir Spot Welding Parameters of AA1050/C10100 Joints
Manufacturing Technology
In this paper, lap joint of 2 mm thickness AA1050 sheets and C10100 sheets using different process parameters were investigated. Experimental plan is designed according to response surface methodology (RSM) where: tool rotation speed, plunge depth and dwell time vary between 500 and 2500 rpm, 2.1 and 3.7 mm and 0 and 8 s respectively. The main affecting and interaction process parameters are evaluated using analysis of variance (ANOVA) methodolgy. Mathematical models describing the relationship between welding parameters and shear failure load (SFL) are developed and the optimal FSSW parameters are specified. Design expert software is used for optimization of friction stir spot welding process parameters using response graphs and contour plots. With 95% confidence level, shear failure load of the dissimilar Al 1050 Cu 10100 joints are predicted using the developed empirical relations. It is found that the optimal results of the SFL is close to the optimal solution obtained from the mathematical model with less than 4% discrepancy.
International Journal of Research in Engineering and Innovation, 2021
In this investigation central composite design (CCD) technique and mathematical model was developed by response surface methodology with three parameters, four levels and 20 runs, was used to develop the relationship between the FSW parameters (rotational speed, traverse speed, and tilt angle) and the responses (tensile strength, % Elongation, micro-hardness and residual stress) of dissimilar aluminum alloys AA5083 and AA6082 were established. The maximum tensile strength (214 MPa) was found at tool rotation speed 1300 rpm, traverse speed 45 mm/min with tilt angle 10 . The maximum micro-hardness (86 HV) was found at tool rotation speed 1300 rpm, traverse speed 45 mm/min with tilt angle 10 . The minimum tensile strength (161 MPa) was observed at tool rotation speed 1000 rpm, traverse speed 30 mm/min with tilt angle 20 . In addition, a numerical model and empirical relationship was developed by design expert software between processing parameters (tool rotation speed, traverse speed, and tilt angle) and response surface parameters (tensile strength, percentage elongation and microhardness at nugget zone) and the optimized value of tensile strength, % elongation, microhardness, and residual stress were observed as 187.6 MPa, 19.93, 78.39 HV and 22.02 MPa respectively.
2021
In this investigation, dissimilar material AA6061-T6 and Cu B370 were joined by friction stir welding (FSW). This paper presents a feasibility study of FSW to join Al-alloy and Cu-alloy. The experiment was conducted using general full factorial design by varying the tool rotation speed, weld speed, and probe offset, and by keeping the plunge depth constant. In this research work, a statistical model was established to build a connection between the process variables and outcomes—yield strength (YS), ultimate tensile strength (UTS) and % elongation (% E). Statistical tools such as analysis of variance and scatter diagrams were employed to evaluate the suitability of the models. In addition, the impacts of the process variables on the tensile properties were investigated. From the experimental results, it can be concluded that (i) an excellent weld joint could be obtained by keeping the softer Al plate at the retreating side with a probe offset of 2.0 mm towards the softer material, a...
International Journal of Research in Engineering and Innovation , 2022
Aluminum and its alloys are lightweight, affordable, high-strength materials that find extensive use in shipbuilding, automotive, construction, aerospace, and other industrial fields. They are also resistant to corrosion. There is a requirement to join components manufactured of various aluminum alloys, namely AA6061 and AA7475, in applications like the aerospace, marine, and automotive sectors. Friction stir welding (FSW) is utilized in this study to join dissimilar plates consisting of aluminum alloys 6061 and 7475. On the tensile strength and percentage elongation of the welded joints, the impact of changing the tool pin profile, tool rotation speed, tool feed rate, and tool tilt angle has been studied. The empirical relationship between the output responses and input parameters was developed, and the perceived optimal values of UTS, % strain and micro hardness at SZ were 205.23 MPa, 16.43 %, and 81.05 HV, respectively. The optimal TS, TRS, and tilt angle values were 87.42 mm min-1, 783.92 rev/m, and 0.48°, respectively. Due to DRX, the microstructure in the weld SZ was characterized by a very fine grain structure. Because of the decreased hardness, the grain sizes in HAZ and TMAZ are virtually comparable, and they discovered coarse grain structure and uneven temperature distribution in that region. When the TRS and TS increase, the grain size decreases in the SZ
International Journal of Research in Engineering and Innovation, 2022
Aluminum and its alloys are lightweight, affordable, high-strength materials that find extensive use in shipbuilding, automotive, construction, aerospace, and other industrial fields. They are also resistant to corrosion. There is a requirement to join components manufactured of various aluminum alloys, namely AA6061 and AA7475, in applications like the aerospace, marine, and automotive sectors. Friction stir welding (FSW) is utilized in this study to join dissimilar plates consisting of aluminum alloys 6061 and 7475. On the tensile strength and percentage elongation of the welded joints, the impact of changing the tool pin profile, tool rotation speed, tool feed rate, and tool tilt angle has been studied. The empirical relationship between the output responses and input parameters was developed, and the perceived optimal values of UTS, % strain and micro hardness at SZ were 205.23 MPa, 16.43 %, and 81.05 HV, respectively. The optimal TS, TRS, and tilt angle values were 87.42 mmmin-1, 783.92 rev/m, and 0.48°, respectively. Due to DRX, the microstructure in the weld SZ was characterized by a very fine grain structure. Because of the decreased hardness, the grain sizes in HAZ and TMAZ are virtually comparable, and they discovered coarse grain structure and uneven temperature distribution in that region. When the TRS and TS increase, the grain size decreases in the SZ.
Arabian Journal for Science and Engineering, 2016
In this work, friction stir spot welding (FSSW) was performed for dissimilar aluminum alloys (AA2024-T3 and AA5754-H114) sheets of 2 mm thick at different tool rotational speeds (800, 1000 and 1250 rpm), plunging times (30, 60 and 90 s) and tool pin profile or geometry (threaded cylindrical with flute, tapered cylindrical and straight cylindrical). Process parameters were optimized by using Taguchi technique and depending on design of experiment (DOE), and data analysis based on the Taguchi method is performed by utilizing the Minitab 17 to estimate the significant factors of the FSSW and main effects using few experimental tests only. It was found that maximum shear force was (2860 N) obtained at best welding process parameters: 800 rpm of rotation speed, 60 s of plunging time and taper cylindrical pin which are obtained from the DOE. Pareto chart of the standardized effects of tensile shear results showed that the pin profile was the most effective parameter than other welding parameters (rotation speed and plunging time). Also it was found that the contribution percentage was 61.5 % for pin profile followed by tool rotation speed 20.1 % and plunging time 18.4 %.
High-strength, precipitation-hardening AA7075-T 6 alloy is used extensively in aircraft primary structures. Friction stir welding process is an emerging solid state joining process in which the material that is being welded does not melt and recast. The FSW process and tool parameters play a major role in deciding the joint strength. Joint strength is influenced by the grain size and hardness of the weld nugget region. Hence, in this investigation an attempt has been made to develop empirical relationships to predict the grain size and hardness of the weld nugget of the friction stir welded AA7075-T 6 aluminium alloy joints. Six factors, five levels, central composite, rotatable design matrix is used to optimize the experimental conditions. The empirical relationships are developed by response surface methodology incorporating tool and process parameters. A linear regression relationship is also established between grain size and hardness of the weld nugget of friction stir welded joints. The weld nugget grain size is related with hardness of the joint. The developed relationships can be effectively used to predict the weld nugget grain size of the joint non-destructively by measuring the weld nugget hardness.
The International Journal of Advanced Manufacturing Technology, 2019
A new proposal for evaluating the relationship between the energy of vibration signals produced by a friction stir spot welding process and mechanical properties of dissimilar AA1050 H24 aluminum alloy-Cu lap joints is presented here. We characterized the vibration signals during the FSSW process to correlate them with microhardness and the failure load of the joints. The influences of dwell time and tool rotation speed on the mechanical properties of the join and its correlation with the energy of the vibration signals were studied. Macro images and microhardness maps of welds were also produced. The strong correlation found confirms that the energy of the vibration signals on the Z and Y axes can be used as an indicator of mechanical properties and as a novel method for weld evaluation. Finally, results based on numerical predictions are compared with the experimental failure load. The mathematical model obtained to calculate failure load values based on friction stir spot welding process parameters, also including the energy of vibration signals, improves the fit from 74.3% (with analyzed process parameters only) to 93.8% with the addition of the energy of the signal.
International Journal of Research in Engineering and Innovation , 2019
The aluminum alloy AA6061 anAA6082 is widely used in the fabrication of lightweight structure with high strength to weight ratio. Friction stir welding is a solid state welding process to overcome the problems encountered in fusion welding. This process uses a non-consumable tool to generate frictional heat on the abutting surfaces. The welding process parameter such as rotational speed, traverse speed and tilt angle play a major role in determining the mechanical properties of welded joint. The present work was designed to identify the most influencing and optimal friction stir welding process parameters on tensile strength and hardness of welded joint of AA6061 and AA6082 using design expert software. Various combination of processing parameters were opt to investigate the optimum values of tensile strength and micro-hardness at nugget zone. The maximum tensile strength (236 MPa) and micro-hardness (115 HV) were found at tool rotation speed 1400 rpm, traverse speed 40 mm/min with tilt angle 20, whereas minimum tensile strength (165 MPa) was observed at tool rotation speed 800 rpm, traverse speed 60 mm/min with tilt angle 20. In addition, a numerical model and empirical relationship was developed by design expert software between processing parameters (tool rotation speed, traverse speed, and tilt angle) and response surface parameters (tensile strength, percentage elongation and micro-hardness at nugget zone).