Application Of Friction Stir Welding Research Articles

Friction stir welding and processing of pipes: a status report on joining, materials, and industry applications

Purpose The purpose of this paper is to compile a comprehensive status report on pipes/piping networks across different industrial sectors, along with specifications of materials and sizes, and showcase welding avenues. It further extends to highlight the promising friction stir welding as a single solid-state pipe welding procedure. This paper will enable all piping, welding and friction stir welding stakeholders to identify scope for their engagement in a single window. Design/methodology/approach The paper is a review paper, and it is mainly structured around sections on materials, sizes and standards for pipes in different sectors and the current welding practice for joining pipe and pipe connections; on the process and principle of friction stir welding (FSW) for pipes; identification of main welding process parameters for the FSW of pipes; effects of process parameters; and a well-carved-out concluding summary. Findings A well-carved-out concluding summary of extracts from thoroughly studied research is presented in a structured way in which the avenues for the engagement of FSW are identified. Research limitations/implications The implications of the research are far-reaching. The FSW is currently expanding very fast in the welding of flat surfaces and has evolved into a vast number of variants because of its advantages and versatility. The application of FSW is coming up late but catching up fast, and as a late starter, the outcomes of such a review paper may support stake holders to expand the application of this process from pipe welding to pipe manufacturing, cladding and other high-end applications. Because the process is inherently inclined towards automation, its throughput rate is high and it does not need any consumables, the ultimate benefit can be passed on to the industry in terms of financial gains. Originality/value To the best of the authors’ knowledge, this is the only review exclusively for the friction stir welding of pipes with a well-organized piping specification detailed about industrial sectors. The current pipe welding practice in each sector has been presented, and the avenues for engaging FSW have been highlighted. The FSW pipe process parameters are characteristically distinguished from the conventional FSW, and the effects of the process parameters have been presented. The summary is concise yet comprehensive and organized in a structured manner.

Modeling and simulation of friction stir welding process: A neural approach

Friction Stir Welding (FSW) stands out as a groundbreaking method in solid-state joining for aluminum alloys, presenting an innovative way to achieve joints of exceptional quality. This research delves into the application of FSW for bonding, focusing on plates that are 6mm thick and made from aluminum alloys Al6063, Al5083, and AL6061, aiming to produce a variety of FSW joints. To evaluate the quality of these joints, the study compares mechanical properties such as tensile strength, safe bending strength, and bending toughness necessary for achieving a 90° bend. The investigation leverages welding data to formulate a neural model, starting with using a conventional feedforward neural model (CFNM). It tackles the limitations of CFNM, including its intensive training requirements and the challenge of dealing with unknown configurations, by proposing a new, more adaptable neural network model known as FNNM. When comparing the two models, it becomes evident that CFNM is constrained by a root mean square error (RMSE) of 7-15%, whereas FNNM marks a significant improvement with a minimal RMSE of 1-3%. This indicates that FNNM improves accuracy and effectively navigates the complexities of modeling with unknown parameters. Through this study, insightful contributions are made to understanding FSW in joining aluminum alloys and developing an advanced neural model capable of predicting the outcomes of welding with greater precision.

Advancements and Applications of Friction Stir Welding: A Comprehensive Review

Friction Stir Welding (FSW) has emerged as a groundbreaking joining technique revolutionizing the field of manufacturing and engineering. This review paper provides an in-depth analysis of the evolution, principles, process parameters, advancements, challenges, and diverse applications of FSW. It discusses the fundamental mechanisms governing FSW, explores the latest developments in tool materials and designs, examines the influence of process parameters on weld quality, and highlights the innovative applications of FSW across various industries. Additionally, this paper addresses the current challenges and future prospects to further enhance the efficiency, reliability, and versatility of FSW technology. Keywords: Friction Stir Welding, Joining Techniques, Weld Quality, Process Optimization, Advanced Materials, Applications, Challenges, Future Directions.

Optimization of Friction Stir Welding Parameters for AA6061-T651 Aluminum Alloy: Defect Analysis and Process Improvement


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Friction Stir Welding (FSW) is an eco-friendly process known for high-quality joints without filler metal. This study investigated the physical properties of FSW-welded joints in AA6061-T651 aluminum alloy by varying the concave shoulder angle. Optimal process parameters were determined through Taguchi optimization using an Orthogonal Array design. Macro and micro testing revealed overlap defects, kissing bond defects, and wormholes in some samples. Systematic experimentation identified key parameters to avoid defects, including tool rotation speed, welding speed, tool tilt angle, tool indentation angle, and shoulder depth. Visual inspection and microstructural analysis played a crucial role in assessing weld quality. Optimizing welding parameters, such as rotational speed, welding speed, temperature, and tool geometry, was highlighted as crucial for defect-free joints. The study offers valuable insights for researchers and professionals in the field, promoting the advancement and application of FSW in aluminum alloy welding.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Highlight:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 FSW: An environmentally friendly welding process with good joint quality.
 Defect Analysis: Identification of overlap defects, kissing bond defects, and wormholes in welded joints.
 Process Optimization: Determination of optimal parameters to avoid defects, including tool rotation speed, welding speed, tool tilt angle, tool indentation angle, and shoulder depth.
 
 Keyword:
 Friction Stir Welding, AA6061-T651 Aluminum Alloy, Welded Joint Analysis, Process Optimization, Defect Prevention

Exploring friction stir welding for joining 316L steel pipes for industrial applications: Mechanical and metallurgical characterization of the joint and analysis of failure

Efficient welding of pipelines is critical for industries like power plants. Friction stir welding (FSW) has shown the ability to provide higher strength joints and is envisaged to be suitable for joining industrial pipelines as well. Hence, the present study assesses the application of FSW for joining 316L stainless steel industrial grade pipes. The welding is carried out by varying the process parameters, viz., spindle speed (rpm) and welding speed (mm/min), within a suitable range under force control mode. Microhardness and tensile tests have been conducted to evaluate the mechanical strength of the joints, whereas microstructure evaluation by optical microscopy (OM) and field emission scanning electron microscopy (FE-SEM) has been done in order to comprehend the mechanical performance of the weldments. It is found that both the selected welding process parameters (spindle speed and welding speed) have significant influence on the metallurgical and mechanical properties of the welded joints. High grain refinement due to dynamic recrystallization (DRX) in the stir zone results in enhanced hardness. At the optimal combination of parameters, i.e., 400 rpm spindle speed and 50 mm/min welding speed, the weld zone displays higher tensile strength than that of base metal. Also, at the same combination of parameters, stir zone of the welded samples displayed maximum hardness (255HV0.5kg). Some of the weldments displayed early failure during tensile tests. The present study also explains the cause of these failures. Optimum amount of heat generation during FSW process is key to achieving defect free good quality weldments.

Effect of induction preheating on microstructure and mechanical properties of friction stir welded dissimilar material joints of Inconel 718 and SS316L

Using an external heat source during friction stir welding (FSW) of high melting point materials is a promising approach to enhance the material flow and reduce the axial load, improving the tool life. In this study, conventional and induction heating-assisted friction stir welding (I-FSW) in joining dissimilar Inconel 718, and stainless steel (SS316L) alloy using the WC-10%Co tool was experimentally investigated. The welding was performed at a constant rotational speed of 300 rpm with welding speeds of 70 and 140 mm/min and 300 °C preheating temperature in the assisted FSW. The results show that the application of friction stir welding resulted in highly refined grains with deformed carbide particles in the stir zone of both materials, which increased mechanical properties. An increase in temperature during the I-FSW process led to a slight increase in the size of the particles and high atomic diffusion of Cr and Mo elements at the interface of the SS316L and Inconel 718 joint, which showed enhancement of the weld strength. In addition, highly dragged SS316L material into the advancing side of the Inconel 718 was observed, which was directly influenced by the preheating temperature and welding speed. The mechanical properties of the joint with preheating significantly improved at a high welding speed (i.e., at 140 mm/min). The tensile strength of the I-FSW joint at 140 mm/min was 683 MPa which was 99.8% of the base SS316L. Dynamic recrystallization resulted in grain refinement, which raised the hardness value. The results also show that preheating reduces downward axial force, enhancing the tool life.

A Contemporary Review on Friction Stir Welding of Circular Pipe Joints and the Influence of Fixtures on This Process

The permanent metal joining processes play a vital role in assembling the complex aluminium structures of the aerospace, automotive, marine, and oil industries. The invention of friction stir welding (FSW) redefined the mechanism of metal joining to produce high-quality welds by eliminating the consumption of electrodes and shielding gases, resulting in economical processes. Research works still lack to explore the application of FSW in complex geometries. In this view, the present work reports a critical review of various geometries welded by FSW, mainly circular geometries that are majorly used in the oil and gas industries. The various aspects of the FSW of pipes, such as process facilitation, process parameters, tool material selection, and tool design selection are discussed. The paper also presents insights into the parameters responsible for the weld quality, the feasibility of optimization techniques, and the status of various fixture arrangements. The facilitation requisites for FSW of pipes are also provided based on the reviews made. The review concludes by discussing the challenges associated with the FSW of pipes, economic aspects, and future research directions.

Residual stress distribution of aluminium-lithium alloy in hybrid process of friction stir welding and laser peening

Using laser peening (LP) to strengthen the welding zone of aluminium-lithium alloy after friction stir welding (FSW) is great important to promote the application of FSW in aerospace field. The simulation model of the “FSW + LP” hybrid process was established by finite element method and verified by the experiment. The effect of laser impact number, laser power density and spot overlap rate on the residual stress distribution in the FSW zone of 2195 aluminum-lithium alloy was studied in detail. It was found that the increase of laser impact number and laser power density impart higher compressive residual stresses. However, the induced compressive residual stress decreases with the increase of impact number due to the work hardening effect. With the increase of overlap rate, the uniformity of the residual stress in the welding zone gradually becomes better, and the value of the residual stress gradually decreases. In this study, the optimal combination of LP parameters are as follows: the impact number, the laser power density and the laser spot overlap rate are 3, 10GW/cm2 and 50%-75%, respectively.

Experimental investigation of defect formation, microstructure and mechanical properties in friction stir welding of AA5086

The joint conditions of a weldment entirely rely on the set of process parameters applied during the welding operation. In friction stir welding (FSW), proper mechanical mixing of the material signifies the appropriate welding variables. The present work aspires to investigate the influence of tool rotational speed (RS), welding speed (WS) and plunge depth (PD) on external as well as internal defect formation, identify the different types of defect encountered during the FSW process, and evaluate the influence of different parameters on tensile properties and microstructure of the joints. In order to achieve the goal of the present work, a detailed experimental investigation was carried out using AA5086-O as base metal. On account of high strength-to-weight ratio, good weldability and high corrosion resistance, friction stir welded joints of aluminum alloys are widely applications in aerospace, automotive, railway and shipbuilding industry. It has been observed that theultimate tensile strength (UTS) of joint tends to decrease when there is increased in the welding speed at constant PD of 0.2 mm and RS of 1400 rpm. Similarly, with consistent PD of 0.3 mm and rotational speed of 2000 rpm, UTS of joints initially enhanced with an increment in welding speed and then reduced eventually. A joint fabricated with maximum rotation speed, intermediate welding speed and the higher plunge depth produced highest tensile strength of 215 MPa which is 16% higher than the conditions required for aerospace applications of FSW for aluminum alloys, as per the standard of American Welding Society (AWS). Microscopic analysis was conducted to scientifically ascertain the grain size, crystal structure and surface morphology of the FSW joints.

A novel non-keyhole friction stir welding process

Keyhole is a defect which seriously restrains the industrial application of friction stir welding (FSW) technique. In this study, a new technique of non-keyhole friction stir welding (N-KFSW) was proposed, which could eliminate the keyhole during the in-situ welding process. Experiments were performed using a 6 mm thick 6061-T6 aluminum alloy plate under different rotating velocities. Due to the unexpected consumption of rotating sleeve during N-KFSW, the N-KFSW tool was simplified to a system consisting of a hollow sleeve and a clamping ring based on the working principle of N-KFSW. Compared with the solid sleeve, this hollow sleeve promoted the material flow below the sleeve. Therefore, the depth of the sleeve-stirring zone (SSZ) was equal to the thickness of the plate when the plunging depth was only 4.2 mm. The SSZ was divided into the sleeve directly affected zone (SDAZ) and the sleeve indirectly affected zone (SIAZ). The material in the SIAZ was transferred by the indirectly stirring effect of hollow sleeve, so the butt interface in the SIAZ was distributed as the S-shape line at the bottom of the SIAZ. The maximum tensile strength of 217.3 MPa was obtained at 1200 rpm, which was 71.5% of that of the base material. The height of the S-shape line shrunk with the rotating velocity increasing, and then governed that the fracture position of the joint transferred to the HAZ from the SSZ. The fracture surface morphology exhibited typical ductile fracture.

Innovative Application of Friction Stir Welding in Practical Teaching

The purpose of the course is to consolidate and improve the students'practical ability, to enhance their innovative consciousness, and to integrate the special welding technology into the traditional welding teaching, let students know how to raise, analyze and solve problems, make students participate in production practice, give full play to the problem-solving ability, improve students'practical ability, and stimulate students'creative thinking ability. To realize the ultimate aim of the practical course of industrial training.

Friction Stir Welding/Processing of High Entropy Alloys (HEAs)

Design and development of high entropy alloys is very important to overcome the shortcomings of conventionally used alloys in applications where operating conditions of temperature and loading are extreme. In this recent paper, the application of Friction Stir Welding for joining the high entropy alloys and also using Friction Stir Processing for improving the mechanical and microstructure properties of high entropy alloys are discussed.

Numerical simulation and experimental research on friction stir welding of 2024-T3 aeronautical aluminum alloy

2024-T3 aeronautical aluminum alloy is a high-strength hard aluminum alloy, belonging to the Al-Cu-Mg series. It is mainly used for manufacturing various high-load mechanical parts such as aircraft skeletons. 2024-T3 aluminum alloy is difficult to be welded with traditional fusion welding, especially welded with another material such as titanium alloy or copper alloy. The welding quality of 2024-T3 aluminum alloy can be improved effectively by friction stir welding, which is favored in the aerospace and shipbuilding fields. Accurately grasping the welding transient evolution mechanism is the key to improving welding quality. It plays an important role in promoting the application of friction stir welding in industry. In this paper, the material physical parameters that change with the temperature were calculated by using the CALPHAD method, and the numerical model for friction stir welding was established. The transient changes in the temperature and stress field of the workpiece and the load of the stirring head were obtained. The temperature, stress, and strain of the advancing side and retreating side were compared and analyzed. The temperature of the workpiece surface and the stress around the keyhole were revealed. Zeiss Sigma 500 field emission scanning electron microscope was used to perform micro-characterization experiments, and the accuracy of the model was verified by comparing the simulation with the experiment. This research is of considerable significance for accurately revealing the mechanism of friction stir welding.

Friction Stir Welded AISI 304 Metal Sheets for Application in Food Implants

Stainless steels are indispensable materials in many industrial fields. They can be easily shaped and joined by traditional welding methods. Some problematics such as possible decrease in corrosion resistance at the welding bead and in the heat-effected zone, residual stress, crack formation and distortions may take place after welding. Friction Stir Welding (FSW) may be used for joining stainless steels in a single pass and for optimising microstructure and mechanical properties of the processed region. The application of FSW to the widely used AISI304 stainless steel is investigated in food implants. The mechanical properties together with corrosion resistance and surface finishing are characterized. A high energy input is chosen for the welding (2000 rpm tool rotational speed and 50 mm/min advancing speed). The stirred zone (SZ) is characterized by optical microscopy. Vickers microhardness in the SZ results 37% higher than in the base material. Tensile tests highlight elongations up to 40% keeping maximum stress values at 600 MPa. All samples pass accelerated corrosion tests that simulate 20 years of cleaning cycles in a typical food implant.

Investigation on surface roughness, ultimate tensile strength, and microhardness of friction stir welded AA7075-T651 joint

From the last two decades the application of Friction Stir Welding (FSW) process is increased in industry due to its advantages such as ecofriendly and improved mechanical properties over the metal inert gas welding and tungsten inert gas welding. In FSW joint is fabricated by the heat generated using rotating, non-consumable tool, whereas the material remains in solid state. In the present work, the mechanical behavior of Aluminum 7075-T651 alloy (AA7075-T651) FSW joints were investigated in terms of surface roughness, ultimate tensile strength (UTS), and microhardness. Investigations were carried out by varying the welding processes parameters, namely the tool rotation at 1000, 1400, and 2000 rpm, and at two levels of welding speed of 20 and 28 mm/min. FSW experiments were performed under dry conditions using a tool having conical pin geometry. Experimental investigations showed a higher value of UTS for FSW joints at tool rotation of 1400 rpm and welding speed of 20 mm/min. the higher value of microhardness and lowest surface roughness at weld bead was observed at lower tool rotation of 1000 rpm. This study suggests further works on the mechanical behavior of high strength AA7075-T651 FSW joint considering the effect of tool geometry and hybrid welding techniques.

Parametric review on friction stir welding for under water and dissimilar metal joining applications

Friction Stir Welding (FSW) is one of the unique solid state welding process developed by “The Welding Institute” in 1991 which produces joints with high strength without negotiating aesthetics as well as weight. Relatively, this process is environmentally safe due to less toxic gas release, less energy utilization and no form of flux is required. This process has proven to be promising technique for joining similar and dissimilar metals including various alloys, hardened materials and composites. Current article is categorized into three sections; the first one focuses current status and parameters of FSW along with their correlations; second section talks about different tools, tool materials and associated defects; last section is highlighting applications of FSW in joining of dissimilar metals development in underwater friction stir welding (UFSW). In addition, performance evaluations of input parameters like tool rotation speed, tilt-angle of the tool, plunge depth, welding speed along with its effect on welding quality, microhardness and tensile properties are discussed. Finally, this article concludes with future scope and challenges in FSW.

Effect of process parameters on tensile strength of Friction stir welded butt joints of thick AA1350 aluminum plates using Taguchi experimental design

Abstract The requirement for defect free welding for critical applications has resulted in continuous development of advanced material joining processes. Friction stir welding (FSW), a solid state welding process has been accepted for joining of a diversity of materials viz aluminium, copper and other low melting point alloys. This mechanical way of joining is also a proven technique that is being used for joining of dissimilar materials efficiently. In this paper, the FSW has been utilizing for joining of thick aluminium plates to widen the industrial application of FSW. The spindle rotational speed, travel speed of tool and tilt angle of the tool were taken to study their effect on the tensile strength of FSW weld joint. The AA1350 grade aluminium plates having 12.7 mm thickness was taken as the work material for joining. Experimentation was carried out according the Taguchi’s L9 orthogonal array. The lowest level of spindle rotation, and highest level of travel speed and tilt angle of tool were obtained as optimal input variables for desired tensile strength of the joint. The confirmation experiments were also done to validate the optimal settings.

Achievement of high-strength 2219 aluminum alloy joint in a broad process window by ultrasonic enhanced friction stir welding

High-strength joints are required to suit a more and more wide industrial application of friction stir welding (FSW). However, the achievement of high-strength joints is generally confined within a narrow process window due to the significant dependence of material plastic deformation on welding parameters. In the present study, ultrasonic enhanced friction stir welding (UFSW) was proposed as a strategy to broaden the process widow for achieving high-strength joints. The results indicated that the tensile strength of UFSW joint only slightly fluctuated around 355–361 MPa, indicating a stable joint efficiency of 81%–82%, even though the welding speed was increased from 300 mm/min to 600 mm/min at a constant rotation speed of 800 rpm. Acoustoplastic effect of the ultrasonic contributes to sufficient plastic deformation of the materials in the stir zone (SZ) and thus welding defects were successfully avoided. With the welding speed increasing, the widths of SZ can stabilize at 4.7 mm in the middle and 3.3 mm in the bottom, respectively. Furthermore, ultrasonic improved the SZ strength by enhancing precipitation strengthening and thus the fracture position was located in the TMAZ. Coarsening of precipitates in the TMAZ cannot make prominent contributions to the resultant strength, leading to a stable joint efficiency of 81%–82%.

Properties of High Speed Friction Stir Welded 6063-T6 Aluminum Alloy

Friction stir welding (FSW) is as known as a revolutionary welding technology, which has come to the foreground in recent years. The low welding speed affects the efficiency of friction stir welding (FSW) and hinders the large-scale commercial application of FSW. In order to improve the welding speed and promote the application of FSW, 6063-T6 aluminum alloy plates were friction stir welded with welding speed of 3000 mm/min. The properties of welds were also tested and analyzed. The results show that the alloy plates can be successfully welded by FSW with high speed welding speed, and the tensile strength of weld can reach over 71 % that of the base material.

Properties of Friction Stir Welded 3003-H17 Aluminum Alloy at High Travel Speeds

As a new-type technology of solid state welding, friction stir welding (FSW) has a very good prospect for application. However, the welding speed is low in the practical application, and most of the time the welding speed is less than 500 mm/min, which hinders the large-scale commercial application of FSW. In this paper, 3003-H17 aluminum alloy plates of 5 mm thickness were butt welded by high speed FSW with travel speed at 1500 and 3000 mm/min and a constant tool rotation speed. The results show that 3003-H17 aluminum alloy can be successfully butt welded by high travel speed. And the UTS of weld joint decreases when the travel speed increases from 1500 mm/min to 3000 mm/min at a constant tool rotation speed of 2000 rpm and shoulder plunge depth of 0.2 mm. The joint efficiency reaches 87% at travel speed of 1500 mm/min, tool rotation speed of 2000 rpm and shoulder plunge depth of 0.2 mm.