Friction Stir Welding Parameters Research Articles

Thermal and Mechanical Investigation of Friction Stir Welding with Disparate Materials AA6061 and AA7075

Background:: The primary objective of this study is to assess the impact of welding conditions on the mechanical properties of friction stir-welded butt joints created from two distinct aluminium alloys, namely, AA6061 and AA7075. Friction stir welding (FSW), known for its innovation and low-energy solid-state bonding technique, was employed in this research. Methods:: FSW experiments were carried out on both AA6061 and AA7075 alloys using a computer numerical control (CNC) machine. The selection and design of the tool geometry were meticulous, with an emphasis on new pin profiles that are nearly flat at the weld contact point. Precisely, four distinct tool geometries were machined from HC-HCr (High carbon, high chromium steel): Circular, Square, Tapered third, and Triangular. Critical process variables that significantly influence weld quality include rotation speed (800 rpm-1400 rpm) and traverse speed (12 to 25 mm/min). These variables were carefully optimized to achieve flawless welds. During the friction stir welding process, the nugget zone undergoes significant deformation, leading to the formation of a new microstructure that substantially impacts the mechanical properties of the joint. Results:: This study comprehensively investigates the thermal and mechanical properties of friction stir welding using aluminium alloys AA6061 and AA7075, considering various tool shapes. Among the four tool shapes employed, two were found to yield higher hardness values (referred to as BH). Notably, the square-shaped tool produced the highest temperature, reaching up to 690ºC, as determined by thermocouple readings. Based on the findings, the optimal FSW parameters for enhancing hardness involve an axial feed and spindle speed of 800 rpm combined with a feed rate of 15 mm/min. These parameters were identified as crucial for achieving the desired mechanical properties in the friction stir-welded joints. Conclusion:: This study presents new developments in FSW technology, which may have patent implications.

Optimization of Process Parameters in Under Water Friction Stir Welded AA2014 and AA6082 joints.

This work focuses on optimizing process parameters in underwater friction stir welding to study their impact on the mechanical characteristics of aluminum 2014 T6 and 6082 T6 joints. The aluminum plates are precisely machined to provide the necessary polish for the underwater friction stir welding process (UFSW). Experiments are designed using Taguchi L-9 orthogonal array, considering three process parameters: speed, transverse speed, and tool angles at three levels each. The aluminum plates of series 2014-T6 and 6082-T6 are securely installed in the machine. The plates will be welded using the UFSW process using a taper pin tool. The welded plates are next subjected to tests to assess their mechanical qualities. Tests for tensile strength, hardness, and impact strength are conducted on the welded area of the plate to determine its mechanical qualities. An ANOVA was conducted to determine the significant influence of each variable. The optimal values achieved are Tensile Strength of 185.592 N/mm2, Hardness of 75.1 (BHN), and Impact Strength of 21.236 Joules at a speed of 1120 rpm, transverse speed of 80 mm/min, and tilt angle of 2 degrees.

Parametric Optimization of Friction Stir Welding of AA6061-T6 Samples Using the Copper Donor Stir-Assisted Material Method

This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse speed (v), the interface coefficient of friction (μ), and the Cu donor material percentage in the plunge, left, right, and downstream zones. Design Expert 13 software was used to identify the number of simulation experiments to be conducted using the Abaqus simulation software. From Design Expert 13, which is a thorough multi-objective optimization analysis software, we were able to identify ideal welding parameters such as a rotational speed of 1222 rpm, transverse speed of 1.1 mm/s, the coefficient of friction of 0.9, and a 19% donor material percentage for the plunge zone. Significant findings demonstrate that increasing the Cu donor material substantially reduced the temperature from 502 °C to 134 °C when the Cu content is increased from 0% to 50%. This integrated modeling and optimization approach provides a practical procedure to identify the best experimental parameters for the process and a new understanding to guide advances for high-quality FSW of aluminum alloys. This work offers a methodology for optimizing the FSW parameters aligned with multifaceted thermomechanical physics.

Enhancing Mechanical Characteristics of 6061-T6 with 5083-H111 Aluminum Alloy Dissimilar Weldments: A New Pin Tool Design for Friction Stir Welding (FSW)

This research addresses the escalating need for lightweight materials, such as aluminum and magnesium alloys, in the aerospace and automotive sectors. The study explores friction stir welding (FSW), a cost-efficient process known for producing high-quality joints in these materials. The experiment involved the welding of dissimilar aluminum alloys (AA5086-H111 to AA6061-T6) using a novel pin tool design with welding parameters such as holding time, pin tool length, tool spindle speed, and linear speed fine-tuned through a design of experiment (DOE) approach. A comparative analysis of two tool designs revealed that the newly introduced design substantially improved mechanical properties, particularly tensile strengths, by 18.2% relative to its predecessor. It is noteworthy that FSW joint efficiency is 83% when using a normal tool design in comparison with 92.2% when using a new tool design at similar FSW parameters. The new tool achieved the parameter values leading to the maximum tensile strength of 317 MPa with 3 mm thickness (Th), 25 s holding time (Tt), 0.1 mm dimension (L), 1600 rpm spindle speed (SS), and 30 mm/min feed velocity (Fr). In comparison, the normal tool achieved a maximum UTS of 285 MPa, 5 mm Th, 25 s Tt, 0.3 mm L, 800 rpm SS, and 90 mm/min Fr. The new tool design, with longitudinal and circular grooves, improves heat input for plastic deformation and alloy mixing during welding. Subsequent analysis of the joint’s microstructure and microhardness shows its similarity to the original alloys.

Performance analysis of Al stainless steel joints fabricated by friction stir welding: Microstructure, mechanical, and tribology

Hybrid structures, incorporating both aluminum and steel, hold potential for applications in automobile, aerospace, and marine industries. This research delves into the effects of friction stir welding on dissimilar joints (AA2024-T3 and SS304), with a focus on microstructural, mechanical, and tribological aspects. The study identifies optimal welding conditions at (tool rotational speed 710 r/min, traverse speed20 mm/min, tool pin offset1.5 mm towards aluminum, and tilt angle of 1.75 deg) that yield a well-defined joint interface, contrasting with flaws observed at a 40 mm/min traverse speed due to insufficient heat input. Under optimal conditions at 20 mm/min, a well-clean serrated interface, defect-free microstructural evolution, improved surface characteristics; enhanced mechanical performance resulting in higher ultimate tensile strength of 319 MPa with joint efficiency of 72.5 and better tribological performance were achieved with lower wear rate of 1.1607 × 10−5 g/Nm compared to those at 40 mm/min, highlighting the crucial role of optimized friction stir welding parameters in achieving high-quality dissimilar joints with desirable properties.

Enhancing surface integrity in friction stir welding through deep rolling and post-weld heat treatment

This study aimed to investigate mechanical surface treatment through deep rolling (DR) and post-weld heat treatment (PWHT) to enhance the surface integrity of an AA7075-T651 aluminum alloy welded through friction stir welding (FSW). The surface integrity of the welded joint was evaluated by analyzing residual stress, microhardness, surface roughness, microstructure, and fatigue life. The experimental design comprised three sets: one set exclusively applied FSW, another set applied FSW followed by DR (FSW-DR), and the last set applied FSW followed by PWHT (FSW-PWHT). Fatigue testing (screening) was performed through a four-point bending test with a bending stress of approximately 300 MPa, test frequency of 2.5 Hz at room temperature, and stress ratio (R) of 0. The FSW parameters included a tool rotational speed of 1600 rpm, welding speed of 30 mm/min, immersion depth of 0.1 mm, dwell time of 15 s, and tool tilt angle of 0°. The DR parameters included a rolling pressure of 150 bar and rolling speed of 1400 mm/min. The results revealed that the residual stress significantly influenced fatigue life. The fatigue test demonstrated that FSW workpieces treated with the DR process (FSW-DR) exhibited the highest fatigue life, showing a remarkable increase of 33.5 % compared with that of untreated FSW workpieces. Moreover, the residual stress changed from tensile to compressive, accompanied by noticeable enhancements in microhardness and surface roughness. These results highlight that FSW followed by the DR process (FSW-DR) positively affects weld surface integrity, resulting in an extended service life for welded components.

Impact of friction stir welding parameters and Al2TiO5 reinforcement on the mechanical, wear, and corrosion performance of dissimilar welded aluminium composite joints

This study investigates the impact of friction stir welding (FSW) parameters on dissimilar AA5052-Al2TiO5/AA6061-Al2TiO5 composite joints. Tool rotational speed (TRS), feed rate, and aluminum titanate (Al2TiO5) content are varied, and their influence on microstructure, mechanical properties, wear resistance, and corrosion behavior is assessed. Joints fabricated with 1200 rpm TRS, 40 mm/min feed rate, and 2 wt% Al2TiO5 exhibit the highest tensile strength (170.11 MPa) due to grain refinement in the stir zone (SZ). Joints with 3 wt% Al2TiO5 have near-base composite hardness (86.12 HV) and exhibit distinct microstructures across different zones. Samples with superior mechanical properties display finer grains in the SZ, while other zones exhibit elongated grains. The sample reinforced with 3 wt% Al2TiO5 (W9) demonstrates enhanced wear resistance attributed to its high hardness. Additionally, the sample fabricated with 1200 rpm TRS, 40 mm/min feed rate, and 2 wt% Al2TiO5 (W15) displays the lowest corrosion rate (0.44 mpy) due to its fine structure. Fracture analysis reveals different failure mechanisms in tensile and wear testing.

Optimization of 2024-T3 Aluminum Alloy Friction Stir Welding Using Random Forest, XGBoost, and MLP Machine Learning Techniques.

This study optimized friction stir welding (FSW) parameters for 1.6 mm thick 2024T3 aluminum alloy sheets. A 3 × 3 factorial design was employed to explore tool rotation speeds (1100 to 1300 rpm) and welding speeds (140 to 180 mm/min). Static tensile tests revealed the joints' maximum strength at 87% relative to the base material. Hyperparameter optimization was conducted for machine learning (ML) models, including random forest and XGBoost, and multilayer perceptron artificial neural network (MLP-ANN) models, using grid search. Welding parameter optimization and extrapolation were then carried out, with final strength predictions analyzed using response surface methodology (RSM). The ML models achieved over 98% accuracy in parameter regression, demonstrating significant effectiveness in FSW process enhancement. Experimentally validated, optimized parameters resulted in an FSW joint efficiency of 93% relative to the base material. This outcome highlights the critical role of advanced analytical techniques in improving welding quality and efficiency.

Assessing the role of friction stir welding tool shoulder profile and parameters on mechanical performance of Al5083 weld joints pre- and post-corrosion exposure

Al5083 alloy sheets were joined by friction stir welding (FSW) by using three different tools having different shoulder profiles (flat, concave and convex) at three different tool rotational speeds. From the cross-sectional microstructures, weld joints obtained at 1120 rpm with three different shoulder profiles were observed as defect free. XRD analysis confirms the development of texture that was dominated with close packed planes. The weld joint mechanical performance was assessed by conducting tensile tests before and after exposing them to 3.5% NaCl solution for 24 h. Combination of concave shoulder profile with 1120 rpm tool rotational speed has given higher strength in the weld joint, compared with base alloy and the other weld joints. The weld joints produced by using flat and concave shoulder profiles exhibited higher mechanical strength even after corrosion attack compared with the base alloy. From the potentiodynamic polarization studies, the three defect free weld joints (processed at 1120 rpm) were measured with lower corrosion current density. The results demonstrate the promising role of FSW to retain the strength against the corrosion initiated mechanical failure of Al5083 alloy by selecting appropriate combination of the shoulder profile and welding parameters.

Grey-Taguchi Approach for Optimizing FSW Parameters in Joining AA6262 and AA5083 Alloys

T his study concentrates on the friction stir welding (FSW) joining of dissimilar AA6262 and AA5083 plates. Four input parameters, namely tool rotational speed (TRS), welding speed (WSP), tool tilt angle (TTA), and pin depth (PDP) are chosen to analyze the output responses of tensile strength (UTS), hardness (HBN), and wear rate (WTR) in welding. The primary objective is to optimize the variables of the FSW process for AA6262 and AA5083 alloys using a combination of Taguchi and Grey Relational Analysis (GRA) methods, while also comprehending the correlations among process variables through the application of these two methods. Utilizing the Taguchi approach, L27 orthogonal array is constructed for conducting FSW experiments. After this, the multi-objective optimization challenge is streamlined into a single-objective optimization task by leveraging the grey relational degree. The significance and impact of the distinct variables are elucidated through the application of Analysis of Variance (ANOVA). Confirmation tests and predictive analysis are performed to validate the optimal variables, which are then compared against the acquired outcomes. The results highlight the welding speed as the paramount parameter, exerting substantial influence over the output responses of the welds in contrast to the other variables under examination. The application of the Grey-Taguchi methodology yields enhancements in Tensile Strength (245.23 MPa) and Hardness (99.2 Hv), while concurrently decreasing the Wear Rate (0.00456 m3/Nm). Furthermore, the Grey Relational Grade exhibits an advancement of 0.1312. These findings collectively signify an increased operational efficiency in the welding process, particularly for dissimilar alloys.

Development of FSW Process Parameters for Lap Joints Made of Thin 7075 Aluminum Alloy Sheets.

The article describes machine learning using artificial neural networks (ANNs) to develop the parameters of the friction stir welding (FSW) process for three types of aluminum joints (EN AW 7075). The ANNs were built using a total of 608 experimental data. Two types of networks were built. The first one was used to classify good/bad joints with MLP 7-19-2 topology (one input layer with 7 neurons, one hidden layer with 19 neurons, and one output layer with 2 neurons), and the second one was used to regress the tensile load-bearing capacity with MLP 7-19-1 topology (one input layer with 7 neurons, one hidden layer with 19 neurons, and one output layer with 1 neuron). FSW parameters, such as rotational speed, welding speed, and joint and tool geometry, were used as input data for ANN training. The quality of the FSW joint was assessed in terms of microstructure and mechanical properties based on a case study. The usefulness of both trained neural networks has been demonstrated. The quality of the validation set for the regression network was approximately 93.6%, while the errors for the confusion matrix of the test set never exceeded 6%. Only 184 epochs were needed to train the regression network. The quality of the validation set was approximately 87.1%. Predictive maps were developed and presented in the work, allowing for the selection of optimal parameters of the FSW process for three types of joints.

Retracted: Optimization of Process Parameters for Friction Stir Welding of Different Aluminum Alloys AA2618 to AA5086 by Taguchi Method

Retracted: Optimization of Process Parameters for Friction Stir Welding of Different Aluminum Alloys AA2618 to AA5086 by Taguchi Method

Sequential procedure to investigate the optimal ranges of process parameters for the FSW of AA8090

The main purpose of this experiment is to evaluate the optimum range of process parameters for Friction Stir welding of AA8090. In the present research work, an experiment has been made to join AA8090 alloy using friction stir welding (FSW) at different rotational speed, welding speed and tilt angle settings. The FSW was done on the CNC (Computer Numeric Control) Vertical milling machine using fixture and a cylindrical threaded tool. For designing experiments, the steepest ascent technique (Factorial Design) was used considering tilt angle, welding speed and rotational speed as input parameters and ultimate tensile strength (UTS) as an output parameter. The metallurgical and mechanical characteristics were investigated and considered while providing the sequential procedure for the optimal range. The optimum range of values observed at tilt angle (1.1° to 1.9°), welding speed (24.6 to 48.2 mm min−1), and rotational speed (1428 to 1876 r min−1). The maximum value of UTS (365 MPa) is obtained at rotational speed of 1652 r min−1, welding speed of 36.4 mm min−1, and tilt angle of 1.5°. Scanning electron microscopy and optical microscope were used for fractrography and microstructural analyses of the joints. The finer grains are observed in the NZ equated to the HAZ and TMAZ.

Metallurgical Behaviour and Characterization on Polymer Metal with HCHCr Tool by using Friction Stir Welding Adopting L27 Taguchi Technique

Friction stir welding is a technique of combining harmless for the environment because it doesn’t use flux or any other shield gas and doesn’t produce hazardous gas. To study the FSW process on composite material this work offers an experimental enquiry and optimisation technique. In this investigated how input process operating factors like tool rotational speed, feed rate and depth of cut affect an output parameter like hardness of welded connections and Ultimate Tensile Strength (UTS), Microstructure and metallurgical on the metal. To achieve this L27 Taguchi approach orthogonal array used to optimise design tests on friction stir welding parameters and also HCHCr tool used to improve the good weld ability and to increase the heat input. The experimental setup is run with several combinations of process parameters such as 900, 1000, and 1200 rpm of Tool rotational speed 20 mm, 25 and 30 mm as feed rate by adjusting the depth of cut values of 5.4 mm, 5.6 mm and 5.8 mm respectively. Additionally, utilising the regression analysis equations (ANOVA) used to identify the significant input parameters how it effects for the output metal structure. Finally, by achieved effective evaluation of the metallurgical and microstructure on the nylon 6A metal by various analysis and Testing.

An Extensive Study and Evaluation of Tribological Properties of Fsw Plates Using Linear Reciprocating Tribometer (LRT)

This study extensively focuses on analyzing the fretting wear characteristics of Aluminum-based hybrid Metal Matrix Composites (MMCs) under dry conditions, essential in understanding materials' tribological properties in mining environments. Aluminum-based MMCs offer improved wear resistance and durability, potentially enhancing mining equipment performance. The investigation targeted Aluminum 7075 alloy-based MMCs, comprising 7% fine greenish Silicon Carbide and 3% chopped E-glass fibers (2-3mm length, 10-14 micrometer diameters). Using traditional stir casting and Friction Stir Welding (FSW) techniques, composite plates meeting ASTM standards were fabricated. FSW parameters like rotation speed and tool feed rate were varied.Analyzing fretting wear on the welded zone, employing different loads through Linear Reciprocating Tribometer (LRT), provided insights into the tribological performance of these Aluminum-based hybrid MMCs. The lightweight and exceptional thermal properties of Aluminum have significantly expanded its use across various industries, enabling partial replacement of ferrous materials, especially in MMCs where Aluminum alloys offer distinct advantages over other materials.This research aids in determining the suitability of these MMCs for demanding mining conditions, where materials endure extreme stress. Understanding their tribological behavior is crucial for potential applications in mining equipment, contributing to longevity and improved performance.

Adhesive reinforced friction stir welded thermoplastic tube-to-tubesheet hybrid joints

Thermoplastic materials are gaining popularity, because of their anti-fouling and chemically inert properties, for use in industrial applications that involve heating and cooling of highly reactive fluids. The current work studies the effect of adhesive reinforcement and radial clearance (RC) on developing friction stir welding (FSW)-based thermoplastic tube-to-tubesheet hybrid joints (TTHJs), which has applications in the thermoplastic heat exchanger and piping industries. The workpieces (sheets and tubes) made of carbon black reinforced high-density polyethylene were used. First, the effect of FSW parameters on the tube pull-out behavior was studied. The fractographic investigations (macroscopic and SEM) suggest that the FSW joints can fail in a brittle, ductile, or mixed manner, depending on the FSW conditions used. The FSW technique provides better load bearing capacity (326 N (0.0 RC), 517 N (0.5 mm RC)) compared to adhesive joints (226 N (0.0 RC), 206 N (0.5 mm RC)). For 0.0 RC, the adhesive reinforcement increased the load bearing capacity by 15.6 %. On the contrary, for 0.5 mm RC, the adhesive reinforcement negatively impacted the load bearing capacity and reduced it by 40.6 %. The FSW technique with 0.5 mm RC provides a higher leak path of 77 % remaining tubesheet thickness (> tube thickness) compared to that of 46.6 % (< tube thickness) achieved at 0.0 RC. However, the adhesive reinforcement can enhance the leak path of 0.0 RC FSW joints to around 100 % remaining tubesheet thickness (> tube thickness) by introducing the adhesive material at the tube-sheet interface.

Optimization of process parameters in friction stir welding of dissimilar aluminum alloys (AA6061–T6 and AA5052–H32)

Optimization of process parameters in friction stir welding of dissimilar aluminum alloys (AA6061–T6 and AA5052–H32)

Cladding of Carbon Steel with Stainless Steel Using Friction Stir Welding: Effect of Process Parameters on Microstructure and Mechanical Properties

The aim of this study is to investigate friction stir welding (FSW) to join A304 austenitic stainless steel and low carbon steel A283 Gr. C in-lap configuration to clad the carbon steel with highly corrosion-resistant stainless steel. Thus, a wide range of FSW parameters were investigated such as FSW tool rotation rate from 200 to 400 rpm, tool traverse speed from 25 to 75 mm/min, and vertical forces of 20 to 32 KN. The FSW parameters combination of high welding rotation rate (400 rpm) and high vertical forces (32 KN) results in rejected joints in terms of surface appearance and clear surface defects. On the other hand, rotation rates of 200 and 300 rpm with different welding speeds and vertical forces resulted in some sound joints that were further investigated for microstructure and mechanical properties. The sound lap joints were examined via optical microstructure, SEM, and EDS investigations. For the mechanical properties, both tensile shear testing and hardness testing were used. The transverse macrographs showed intermixing between the two dissimilar materials with an almost irregular interface. The hardness profile in both materials showed a significant increase across the different regions from the Base Material (BM) to the nugget zone, with a maximum value of 260 Hv in the stainless steel and 245 Hv in the carbon steel. This increase is mainly attributed to the grain refining in the weld region due to the dynamic recrystallization and transformations upon the thermomechanical cycle. The tensile shear load of the joints varied from 20 to 27 KN for the FSWed joints, with the highest joint tensile shear load of 27 KN for that produced at 300 rpm tool rotation and 25 mm/min welding speed.

Examining the influence of Scandium interlayer and parameters on the mechanical behaviour in FSW of AA 5754-H111 plate through response surface approach

Friction stir welding (FSW) was conducted on 5754-H111 aluminium alloy using a response surface methodology to examine the impact of process parameters on the efficiency of the weld. The key FSW parameters were the percentage of scandium inclusion in the interlayer, tool rotational speed, and tool travel speed. The significant responses were identified as the tensile strength of the weld and the hardness in the weld zone. An Al-Mg-Sc alloy was employed as an interlayer material between the 5754 plates to enhance the strength in the weld zone. The addition of Scandium had a more pronounced effect on the hardness of the stir zone. The tensile strength was increased by raising the tool’s rotational speed. The results showed that the maximum tensile strength of the joints was 225 MPa and the hardness was highest at 118 HV1 in the weld stir zone. The introduction of Scandium improved the joint strength by producing fine grains and Al3Sc precipitates. The welding speed had the least impact on the tensile properties of the joint among all the variables investigated.

Numerical investigation of the influence of friction stir welding parameters on the microstructure of AISI 410S ferritic stainless steel joints

Stainless steels are widely used in industry due to their corrosion resistance properties. Ferritic stainless steels are cheaper than austenitic steels because the former do not contain nickel, an expensive alloying element. However, when ferritic stainless steels are used in manufacturing industries, they undergo microstructure transformations that can result in corrosion. Furthermore, the conventional welding processes that are most commonly used can also cause microstructural changes, such as high grain growth, due to the high thermal inputs applied, and precipitation of deleterious phases. On the other hand, Friction Stir Welding (FSW) avoids such problems due to its intrinsic features and has, therefore, become a viable option for the welding of ferritic stainless steels. This technique imposes high deformation rates, enough heat to soften the material and provides the necessary conditions to promote dynamic recrystallisation and, consequently, prevent the grain growth that occurs in conventional welding. The current investigation is clearly justified due to the vast potential of ferritic stainless steels in the industry using FSW. The main goal of this work is to simulate the FSW process, analyse the possible structural changes in the material and provide the factors that most influence the quality of welds when using this process, such as temperature, strain rate, and changes in the viscosity of the material. The results were able to predict the regions with the smallest grain sizes due to dynamic recrystallisation. Furthermore, the calculated Zener-Hollomon values could be directly linked to the grain size: when the Zener-Hollomon parameter increases the grain size decreases.