Friction Stir Welding Tool Research Articles

Influence of Tool–Base Metal Interference on the Performance of an Aluminium–Magnesium Alloy Joined via Bobbin Tool Friction Stir Welding

Bobbin tool friction stir welding (BTFSW) is a variant of the FSW process which uses the special two-shoulder tool that forms the top and bottom of a weld surface. As such, a significant simplification of the welding setup is achieved. One of the dominant parameters of the BTFSW process is the interference between the tool shoulder pinch gap and the weld metal thickness. In this research, the influence of interference of the square pin tool with convex shoulders on process temperature, microstructure, tensile, impact, and bend performance were studied, and appropriate correlations were devised. The base metal was an aluminum–magnesium alloy in which the interference varied in the range of 0.1 to 0.5 mm. Wormhole defects and irregularities were found in all specimens except in the specimen welded with 0.4 mm interference. An optimal interference of 0.4 mm resulted in the best mechanical properties, which, in terms of tensile strength and reduction of area, were similar to the base metal. Furthermore, the impact strength was significantly higher, which was attributed to the grain refinement effect in the nugget zone.

Micro-hardness evaluation of the bobbin tool-friction stir welded AA6063 using regression-based machine learning

This research work focuses on the prediction of micro-hardness in Bobbin tool friction stir welding (BT-FSW) of AA6063 plates using machine learning (ML) models. The objectives are to determine the effect of process parameters on micro-hardness and to compare the performance of various ML techniques. The dataset obtained from experimental runs is subjected to classical supervised learning techniques such as LR, SVR, DTR, KNN, as well as ensemble techniques including Bagging, Random Forest, Extra Trees, AdaBoost, Gradient Boosting, and Extreme Gradient Boosting. The results show that ML models effectively predict micro-hardness, with ensemble methods outperforming individual techniques. The tool rotational speed is identified as the most influential parameter affecting micro-hardness.

Thermal Effect of Bobbin Tool Friction Stir Welding on the Mechanical Behavior of High Density Polyethylene Sheets: Experimental Study

Bobbin friction stir welding (BT-FSW) is a variant of the conventional friction stir welding (C-FSW). This method has been applied of welding high density polyethylene (HDPE) plates; where a rotating symmetrical tool causes a fully penetrated bond, it can weld the upper and lower surface of the work-piece in the same pass. BT-FSW process involves complex heat generation and HDPE flow, which directly affects on the weld area and on mechanical properties of welded joint. Heat generation and material flow during BT-FSW are significantly affected by the tool design features, process parameters and mechanical behavior of work piece materials. Studying the temperature of polyethylene sheets welded by BT-FSW can help in analyzing the mechanism of weld formation and also can provide theoretical guidance for the tool design, process parameter selection and even new process development. In the unique work described in this paper, the 11.4 mm-thick HDPE plates were welded successfully by bobbin-tool friction stir welding. Measurements of the material temperatures were performed by thermocouples which are placed near and at the weld seam. The weld quality was determined in terms of no defects in the stir zone and the tensile strength of the joint. It was found that considerable melting occurred between the rotating shoulders and on the trailing side of the rotating pin. Movement of the molten material by the rotating tool created a very black band in the stir zone. Thermocouples measurements indicated that the temperatures were higher on the advancing side (AS) compared to those on the retreating side (RS). Tensile tests and hardness measurements were performed on welded and seamless sheet samples. The results were analyzed to compare the mechanical properties. To demonstrate the variation in micromechanical properties between welded and seamless sheet samples, micro hardness (HV) testing was used to explain the difference. The HV of the HDPE plates weld by BT-FSW, were relatively symmetrical with respect to the parting line. The maximum hardness levels were reached in the weld bead at around 66 HV in the welded nugget; there was a rise in the level of hardness, in particular at retreating side (RS) and at advancing side (AS) where the value reached 68.60 HV.

Development of a machine learning model to predict the friction stir welding tool condition

Tool damage results in surface polishing and dimensional accuracy losses for machined parts, as well as potential damage to a workpiece or machine. In the industrial business, tool condition monitoring (TCM) is significant. As a result, it is essential for production efficiency and profitability. In order to prevent damages from occurring, also known as predictive maintenance, we may use the TCMS to identify tool wear and damage that eventually impacts the workpiece. Machine learning models play a significant part in TCMS by way of a GUI that identifies the tool's failure state. This method can be applied in any kind of system which is used in the industry to predict the damage. This TCMS is applied in a friction stir welding machine (FSW) to predict its tool wear. Friction stir welding, an eco-friendly solid state welding method, is used to join two metals that are difficult to fuse together using conventional fusion welding. FSW is largely recognized as the most important innovation in metal joining technology in the previous decade. This FSW has been widely employed in numerous sectors such as shipbuilding, computer covers, vehicles, and so on. Developing a GUI for the prediction of tool condition in FSW with AZ31B(Mg) as a workpiece is a novel approach. In this condition monitoring technique, the real time vibrational data is collected with the help of an accelerometer. These data’s are being processed and features are extracted and a proper classifier is used to predict the faults. This paper aims to develop a part of TCMS through vibrational data. GUI and ML models were developed to predict the condition of FSW tools. The ML model includes Decision Tree, Random Forest, Light Gradient Boosted Machine Classifiers. Among all these Light Gradient Boosted Machine Classifiers perform better. Using this Classifier a GUI is built to predict the condition.

Study on temperature field, microstructure, and properties of T2 pure copper by bobbin tool friction stir welding

Study on temperature field, microstructure, and properties of T2 pure copper by bobbin tool friction stir welding

Friction stir welding of AA5010 aluminum alloy to St-12 carbon steel using CoCrCuFeNi high entropy alloy interlayer

Dissimilar friction stir welding (FSW) of AA5010 aluminum alloy to St-12 carbon steel using an equiatomic CoCrCuFeNi high-entropy alloy (HEA) interlayer was investigated. Mechanical properties of the joints fabricated under different plunge depths of the FSW tool were examined and correlated to microstructural evolutions. The incorporation of the HEA interlayer successfully prohibited the formation of AlFe intermetallic compounds (IMCs). Also, the interlayer was metallurgically consistent with both base metals, although quite thin complex IMC layer was formed at the aluminum/HEA interface as a result of sluggish diffusion of constituent elements of HEA towards the aluminum. The application of suitable plunge depth in the steel part, i.e. 0.2 mm, resulted in the perturbation of the HEA/steel interface and then the formation of interfacial mechanical interlocks that were beneficial to the strength of the joints. However, excessive FSW tool plunge depth caused large voids to form near hooks, acting as stress concentration areas during shear-tensile test. An appropriate plunge depth of the tool achieved an ideal joint that exhibited fracture from the aluminum side rather than the joint interfaces. It also provided a strength value as high as 80 % of the nominal strength of aluminum base metal.

Effect of silicon nitride microstructure on characteristics of FSW tool for steel and tool life

Friction stir welding (FSW) has been widely used in the welding of low melting point metal, such as Al alloy or Cu alloy. However, high melting point metal, such as Fe alloy, it is difficult to be welded by FSW because of short life or the high price of FSW tools. Silicon nitride tool can have both long life and low cost. In order to obtain design guideline for silicon nitride FSW tool, the relationship between the mechanical properties and tool life was examined. Two silicon nitride materials which had different microstructure were prepared. One of them had lower high-temperature mechanical properties and the other had higher properties. Tools made by them could join the SUS 304 plate under the following conditions; welding speed was lower than 1000 mm/min, and revolutional pitch was lower than 1.8 mm/r. Even the tool which had excellent mechanical properties at high temperature worn faster when the joining temperature was 950 °C or higher. The tool with excellent high-temperature mechanical properties had a tool life 6 times longer than the other tool. It is considered the life of the tool was improved when the crystallization of the grain boundary phase promoted the rise in the melting point of the grain boundary phase and the precipitation of silicon oxide during FSW.

Investigation of the Effect of Tool Temperature on Microstructure, Hardness, and Wear Behaviour of Aluminium 6061-T6 Alloy Welded by the Friction Stir Welding Process

The friction stir welding (FSW) tool is a critical component to the success of the welding process. The aim of the paper is to investigate the effect of tool temperature on the microstructure and mechanical properties of the aluminium alloy during the friction stir welding process. The welding experiment was conducted at a tool rotational speed of 550 rpm, and tool temperature was measured with the increment of a 60 mm distance. Three different tool temperatures were obtained, and samples were characterised by scanning electron microscopy (SEM). The ASTM E384 standard was followed when conducting the Vickers hardness test, and material wear behaviour was tested using the ASTM G99 tribology testing standard. The results show that the tool temperature increases with distance during the FSW process (40.5, 46, and 54°C). A high tool temperature produces the weld butt with high mechanical properties (87.5 HV). The wear rate is low at a high tool temperature ( 1.169 E − 006 mm3/N/m).

Friction Stir Welding of Aluminum in the Aerospace Industry: The Current Progress and State-of-the-Art Review.

The use of the friction stir welding (FSW) process as a relatively new solid-state welding technology in the aerospace industry has pushed forward several developments in different related aspects of this strategic industry. In terms of the FSW process itself, due to the geometric limitations involved in the conventional FSW process, many variants have been required over time to suit the different types of geometries and structures, which has resulted in the development of numerous variants such as refill friction stir spot welding (RFSSW), stationary shoulder friction stir welding (SSFSW), and bobbin tool friction stir welding (BTFSW). In terms of FSW machines, significant development has occurred in the new design and adaptation of the existing machining equipment through the use of their structures or the new and specially designed FSW heads. In terms of the most used materials in the aerospace industry, there has been development of new high strength-to-weight ratios such as the 3rd generation aluminum-lithium alloys that have become successfully weldable by FSW with fewer welding defects and a significant improvement in the weld quality and geometric accuracy. The purpose of this article is to summarize the state of knowledge regarding the application of the FSW process to join materials used in the aerospace industry and to identify gaps in the state of the art. This work describes the fundamental techniques and tools necessary to make soundly welded joints. Typical applications of FSW processes are surveyed, including friction stir spot welding, RFSSW, SSFSW, BTFSW, and underwater FSW. Conclusions and suggestions for future development are proposed.

Friction Stir Welding of Non-Heat Treatable Al Alloys: Challenges and Improvements Opportunities

Friction stir welding (FSW) is an effective solid-state joining process that has the potential to overcome common problems correlated with conventional fusion welding processes. FSW is used for the joining of metallic materials, in particular Al alloys (non-heat-treatable and heat-treatable). The heat produced by the friction between the rotating tool and the workpiece material generates a softened region near the FSW tool. Although the heat input plays a crucial role in producing a defect-free weld metal, it is a serious concern in the FSW of work-hardened non-heat-treatable Al alloys. In this group of alloys, the mechanical properties, including hardness, tensile properties, and fatigue life, are adversely affected by the softening effect because of grain growth and reduced dislocation density. Considering this challenge, work-hardened Al alloys have been limited in their industrial use, which includes aerospace, shipbuilding, automotive, and railway industries. The current comprehensive review presents the various approaches of available studies for improving the quality of FSW joints and expanding their use. First, the optimization of welding parameters, including the tool rotational and traverse speeds, tool design, plunge depth, and the tilt angle is discussed. Second, the incorporation of reinforcement particles and then underwater FSW are stated as other effective strategies to strengthen the joint. Finally, some supplementary techniques containing surface modification, bobbin tool FSW, copper backing, and double-sided FSW in relation to strain-hardened Al alloys are considered.

Friction Stir Welding of Dissimilar Materials with Reinforcement of Copper Particulates

In this study, the controlled input parameters namely welding speed and spindle speed were optimized by Taguchi method for reinforcement of copper particulates in aluminium alloy (AA6061-AA6063-T6). High carbon and high chromium steel i.e. tool steel D2 type material is used as a friction stir welding tool. Subsequently, the effects of the process parameters were investigated. The signal-to-noise ratios and analysis of variance were applied for statistical analysis. The outcome shows welding speed is the significant parameter than spindle speed. Under the optimum process parameters, 1400 rpm with 16 mm/min were shown best values such as 61.60 MPa for ultimate tensile strength and 91 hardness values. It means moderate spindle speed and lower welding speed develop higher heat. Subsequently, it is also shown that the feasibility of signal-to-noise ratio is responsible to improve welding quality after reinforcement.

In-situ workpiece perception: A key to zero-defect manufacturing in Industry 4.0 compliant job shops

Job shop manufacturing is characterized by excellent job flexibility and highly customizable products. The dynamic nature of jobs in this manufacturing segment poses a relatively high challenge to actualizing zero-defect manufacturing (ZDM). The continuous emergence of new engineering materials and improved consumer’s contributions to product development driven by IIoT further complicates the uphill task. This study develops a methodological framework that positions in-situ workpiece perception and industrial recommender system as tools to trivialize the challenge of ZDM in job shops. In-situ workpiece perception was experimented using a case study of friction stir welding (FSW), a thermomechanical manufacturing process where existing algorithms for online quality assessment are material-specific. The novelty in this study is deciphering unique applications for the hitherto jettisoned sensor data acquired prior to the FSW tool traverse (the actual welding stage), ensuring that the material perception process does not induce defects in the products. This study presents two major contributions towards attaining first-time-right ZDM in job shops. First, a novel interlink for IIoT-driven production planning to aid the selection of optimal process parameters; second, the selection of appropriate quality assessment algorithms during the welding process.

Analysis of Friction Stirs Welding Using the PROMETHEE Method

In friction stir welding (FSW) near the tool Thermo-mechanical condition of the piece at work the aim of the present work is to simulate Using general purpose software for this A fully coupled three-dimensional solid mechanical model has been created. ABAQUS/Arbitrary Lagrange- Eulerian (ALE) formulation re-meshing and large Enables transparency with distortions. Of FSW One of the least understood aspects of in friction stir welding (FSW) near the tool. For different welding speeds, forces and equipment Temperatures are recorded accurately in standard welding are done. Conditions. Numerical the simulations implemented are arbitrary Based on the Lograngian Eulerian (ALE) formula have the key aspect of the numerical approach is the palette and contact and friction between the tool accurate calculations of surface area. Accurate calculation of surface area. PROMETHEE is a priority for assessment enrichment Ranking system and its interactive help Descriptive complementary geometric analysis known as Promethee methods. In this The PROMETHEE method is the best solution from the analysis the shorter the distance and the longer the negative-ideal solution Determines the solution with the distance, but of these distances the comparison was not considered significant. Alternative: Conductivity, Thermal capacity, Density, Effusively, Emissivity. Evaluation Preference: Work piece, FSW Tool, Backing plate, strength, and conductivity. As a result FSW tool is very low As a result passive tool is very low got first rank for strength. The value of the dataset for Friction stir welding in PROMETHEE method shows that it results in strength is and top ranking.

Analysis and construction of a pneumatic-powered portable friction stir welding tool for polymer joining

ABSTRACT The increasing use of polymer products in transportation and almost all sectors is a distinctive sign of the current decade. On-site repair of defects along the spatial path are important advantages of a portable welding and repair system. The current article presented an in-house developed pneumatically powered portable set-up and tool for defect repair based on friction stir welding (FSW). The suggested tool can be used for welding polymer products such as car bumpers, motorboats, and polymer vessels. Further, acrylonitrile butadiene styrene (ABS) polymer specimens were joined by FSW and friction stir spot welding (FSSW), and the maximum temperature was monitored. FSW process parameters: rotational speed and traversing velocity, and FSSW parameter: rotational speed and dwell time, were varied, and the design of experiment-based investigations was carried out. Response surface method (RSM) and analysis of variance (ANOVA) were used to analyse the results. The acceptable results were obtained for rotational speed of less than or equal to 1100 rpm and welding velocity lower than 6.5 mm/min (for FSW). Good quality welds were obtained for dwell time equal to or higher than 25 s (for FSSW). The preferred temperature for a good quality weld was found to be 105°C in both processes.

Temperature Distribution within the Friction Stir Welding Tool

Temperature Distribution within the Friction Stir Welding Tool

Evaluation of Pure Titanium Welded Joints Produced by Underwater Friction Stir Welding

Underwater friction stir welding (UWFSW) is an advancement of conventional friction stir welding, which is performed in air. The need for welding underwater calls for more information to be explored in the welding of different materials. The aim of this research is to investigate the UWFSW of 2 mm titanium sheet joints for their tensile and microstructural properties and compare them with the results of friction stir welding (FSW) performed in air. Also, nondestructive tests, such as radiography and dye penetrant tests, were carried out to identify the occurrence of any weld defects. The rotational speed of the FSW tool and its travelling speed were considered process parameters, while other parameters like the tilt angle of the tool, shape of the tool pin, etc. were kept constant. The results show that the welded joints with higher strengths were achieved at a lower travelling speed of 140 mm/min at a rotational speed of 400 and 500 rpm in FSW and UWFSW, respectively. The mechanical properties such as yield strength, tensile strength, and hardness are improved in UWFSW when compared with conventional FSW due to the proper mixing of the metal and effective cooling due to the water environment. In underwater FSW, the improved YS and TS values are observed, which are 95.9% and 75.1% of the base metal values, respectively, when the tool rotational speed is 400 rpm and the travelling speed is 140 mm/min. However, the elongation % is much lower in both FSW and UWFSW when compared with the base metal. These results are supported by microstructure and nondestructive test outcomes.

Investigating the role of different components of friction stir welding tools on the generated heat and strain

Temperature and strain in friction stir welding (FSW) induced by the FSW/FSP tool play a critical role in successful welding. In order to properly design the FSW/FSP tool, it is necessary to understand the role of each component of the probe and shoulder of the tool in heat and strain generation. In this study, the heat and strain generated by the tool were numerically modeled using a thermo-mechanically coupled 3D FEM model. To investigate the effect of tool probe and shoulder on heat and strain production, a tool without a probe, a tool without a shoulder, and a complete tool were modeled, and the contribution of each component in heat and stress production was calculated. The results show that, in contrast to plastic deformation, frictional heat generation is the main mechanism for increasing workpiece temperature. Also, about 90% of the heat is generated by the tool shoulder, and the tool pin alone is not able to generate heat and strain in the samples.

Modeling and optimization of tool parameters in friction stir lap joining of aluminum using RSM and NSGA II

Friction stir welding (FSW) success depends heavily on the temperature and strain the FSW/FSP tool induces. This study examined the influence of FSW tool characteristics like shoulder and probe diameter and probe height on temperature, forces and failure load of welding of AA5083 alloy using the response surface methodology (RSM). The study’s setup consisted of three factors, three levels, and 17 experimental runs. In order to determine the welding temperature, a thermocouple was placed inside the samples. Also, the force during the process was measured using a fixture designed for this purpose. The generated model’s suitability at a 95% confidence level was assessed using an analysis of variance. Using RSM, a relationship was discovered between input parameters, including tool settings and output responses, such as temperature, force, and joint mechanical properties. This relationship was then used to discover the best process parameters using a hybrid multiobjective optimization. Hybrid multiobjective optimization recommends a probe diameter of 5.1 mm, a shoulder diameter of 17.63 mm, and a probe height of 3.86 mm as the optimum tool. This study discovered that the most important factors influencing temperature force and failure load were shoulder diameter, probe diameter, and probe height, respectively.

Tool pin profiles effect on mechanical properties of friction stir welding of dissimilar aluminium alloys

Aluminum alloys are now widely used in a many of the engineering applications because of due to their light weight and exceptional characteristics. In many precision sectors such as automobile, railway, aerospace, and marine structures joining is considered one of the most complicated phenomena because rigid tolerances are necessary throughout distinct product assembly. Friction stir welding (FSW) of various grades of aluminium alloys has attracted significant industrial and scientific attention due to its ability to transform into a high-quality joint product. Fabricating such alloys with traditional fusion welding is a difficult process because of many metallurgical problems. In the present experimental work, the effect of different pin profiles tools on friction stir welding of AA-6061 T6 and AA-2014 T4 has been investigated. Friction stir welding has been performed using different pin profiles tools cylindrical, square and tapered and keeping the rotational speed and feed rate constant. This experimental investigation shows that by using square profile tool for friction stir welding improves the mechanical properties of the joint. It has also been observed that hardness of the weld is greater for square pin profile. Also the microstructure of the samples was observed.

Effect of Friction Stir-Welding Tool Pin Geometry on the Characteristics of Al-Cu Joints

Effect of Friction Stir-Welding Tool Pin Geometry on the Characteristics of Al-Cu Joints