Friction Stir Research Articles

Quantitative analysis of influences of defects on mechanical properties in refill friction stir spot welding Al–Mg-Li alloy joints

This research significantly extends the previous studies by providing a quantitative analysis of the impact of defect size on the mechanical integrity of 5A90-T3S Al–Mg–Li alloy joints via refill friction stir spot welding (RFSSW). It particularly elucidates the pronounced effects of the defects at both vertical and horizontal interfaces on the mechanical properties (such as shear and tensile strengths). Notably, larger defects at the vertical interface are found to critically undermine the tensile strength, whereas the defects at the horizontal interface primarily diminish the shear strength. Moreover, the presence of cavity defects at the interface junctures is identified as a pivotal factor severely compromising joint performance. Comprehensive mechanical testing coupled with detailed statistical analysis underscores the critical importance of precise control over welding parameters and the implementation of rigorous inspection protocols to minimize defect impacts, thereby bolstering the structural integrity of aerospace components.

Enhanced Mechanical Properties of Mg-8Li Dual-Phase Alloy Processed by Friction Stirring Versus Hot-Extrusion

The microstructure evolution, texture and tensile properties of the Mg-8Li dual-phase alloys processed by hot-extrusion and friction stir processing were investigated. It was found that the friction stir processing was more advantageous when compared with hot-extrusion in achieving the superior mechanical properties. The tensile strength, yield strength and elongation of the as-FSPed alloy reached 235.4 MPa, 185.3 MPa and 35.6%, respectively. The outstanding strength-ductility combination of the ­as-FSPed Mg-8Li alloy was ascribed to refined grains, weakened texture and formation of high-fraction high angle grain boundaries.

Study of Friction Stir Welding effects on the Microstructure & Mechanical Properties of AA3003 Pipes

Abstract In the present study, similar Aluminum (AA3003) alloy pipes with a thickness of 5 mm were friction stir welded using a high-speed steel (HSS) tool with a cylindrical pin profile. Welding was done at three different rotational speeds and three traverse speeds corresponding to pipes of three different diameters. Six combinations of rotational speed and traverse speed were used to observe the effect of energy input on the properties, specifically tensile strength and microhardness, as well as grain size of the resulting microstructure. This systematic variation in welding parameters was designed to assess how changes in energy input influence both the mechanical performance and microstructural attributes of the welded joints. The tensile test results indicated that an ultimate tensile strength (UTS) of 84% relative to the base metal was achieved at a rotational speed of 900 rotations per minute(rpm) and a traverse speed of 131.94 mm/min. The impact energy corresponding to these parameters was found to be 38% more than base metal which is a remarkable contribution. This combination of welding parameters facilitated optimal material flow and bonding, resulting in improved tensile properties of the welded joint. Additionally, the tensile results showed a consistent pattern in the tensile failure of the welded samples, where the joint failure occurred at the location with the lowest hardness in the welded region. This correlation highlights the critical influence of hardness distribution on the structural integrity of the welds, indicating that areas with reduced hardness are more prone to failure under tensile loading of FSWed joints.

Effect of Friction Stir Welding on Mechanical Properties and Formability of Aluminum Alloy-AA1100

Effect of Friction Stir Welding on Mechanical Properties and Formability of Aluminum Alloy-AA1100

ANALYSIS OF FRICTION STIR WELDING JOINTS ON HIGH DENSITY POLYETHYLENE (HDPE) DUE TO CHANGE IN MATERIAL TEMPERATURE AND SPINDLE ROTATION

Friction stir welding (FSW) can be a solution in solving the problem of joining thermoplastic polymers which are difficult to do with fusion welding. Selection of the proper FSW connection parameters can produce optimal connection quality in HDPE material joints. In friction stir welding, the heat of welding is used to raise the temperature of the material from its initial state to the solid state temperature. If the material temperature (T0) is increased above room temperature (TRoom), while the FSW welding parameter is constant, then at a certain increase in T0 it will produce excess welding heat which results in excessive softening or even melting of the material being welded. Therefore, the material temperature setting (T0) becomes an important parameter FSW The process of connecting the HDPE plates with friction stir welding was carried out by varying the material temperature (T0 ) of TRoom, 50 0C, 75 0C and 100 0C. While the spindle rotation varies 2000 rpm and 2500 rpm. Other parameters controlled include the type of square butt joint, 5 mm HDPE plate thickness, 20 mm/min feed rate, 0.1 mm plunge depth, 20 mm tool shoulder diameter, 4.5 mm pin length and 6 mm pin diameter. The result is that the higher the spindle rotation and the material temperature during the welding process causes the FSW peak welding temperature to increase. The highest peak weld temperature was obtained at variations in material temperature (T0) 100 °C with a spindle rotation of 2500 rpm, which is 123.2 °C or 94% of the melting temperature of HDPE. The hardness of the weld nugged area is still lower than the hardness of the base material. The highest average tensile strength of the research variations was achieved at a spindle rotation speed of 2500 rpm and a material temperature of 75 °C of 16.8 MPa, higher than the average tensile strength of the base material which is 15.1 MPa.

DEAR-Taguchi analysis of buckling load and shear force in AA6061-T6 friction stir spot welds

DEAR-Taguchi analysis of buckling load and shear force in AA6061-T6 friction stir spot welds

Online tensile strength prediction considering geometric and physical characteristics during FSW 2219-T8 aluminum alloy plate

Tensile strength of joints of friction stir welded (FSW) thick 2219-T8 aluminum alloy plates, is affected by multiple geometric and physical characteristics, such as axial force, welding temperature, gap, and mismatch of the butt face, which makes it difficult to predict the tensile strength with high precision on line. At present, simple welding process prediction based on temperature or force is difficult to achieve accurate control of complex welding process. In this paper, a multi-information fused one-dimensional Convolutional Neural Network (1DCNN), combining geometric and physical characteristics of welding process, was proposed to predict the tensile strength of joints. Firstly, the experiments of FSW thick 2219-T8 aluminum alloy plates were conducted and the axial force, welding temperature, gap and mismatch of the butt face are measured. Then, the measured multi-source data was fused through down-sampling technology. Before training, the Particle Swarm Optimization (PSO) and Long Short-Term Memory (LSTM) were adopted to optimize the initial learning rate and layer structure of the model. The experiment results showed that the proposed model can accurately and quickly predict the tensile strength of thick 2219-T8 aluminum alloy joints with the mean absolute percentage error less than 2%. In addition, metallographic analysis revealed that the joint tensile strength is interlocked with weld defects and fine grain strengthening. The research lays a foundation for welding quality control of FSW.

Experimental investigation of the friction stir welding process of AA5059 and AA7079 and prediction using fuzzy approach

Aluminum alloys AA 5059 and AA7079 have high strength, excellent weldability, and corrosion resistance, widely used in train and truck bodies, armored vehicles, and defense applications. Recent materials engineering tasks call for minimizing material weight and to achieve this objective, the solid-state joining approach of Friction stir welding (FSW) is utilized for material joining. FSW has produced sound welds with high joint strength and good ductility. This research investigates the weldability of AA5059 and AA7079 dissimilar aluminum alloys. In this FSW process, a threaded tapered cylindrical tool pin profile was selected, and welding trials were conducted at three different speeds of 500, 750, and 1000 rpm, with the 75 mm/min constant feed rate. The Taguchi L9 orthogonal array was selected to design the process parameters, that is, tool traversing speed, rotational speed, axial force, feed rate, and effect on dissimilar aluminum weld joints. The Mamdani-type fuzzy logic model predicted welded specimens’ ultimate tensile strength and yield strength. Microstructural analysis revealed that the grains in the stirring zone had undergone a full transformation into homogenous, evenly distributed, refined grains, which had a positive impact on the remarkable mechanical properties.

Role of microstructure on the varying corrosion behavior across the UNS S32750 super duplex stainless steel friction stir weld

Role of microstructure on the varying corrosion behavior across the UNS S32750 super duplex stainless steel friction stir weld

Innovative techniques for joining and processing of some aluminum alloys used in the aircraft industry

The continuous development of various cutting-edge fields of science and technology, including the aerospace industry, is advancing at an accelerated pace. To meet current technical, economic, and environmental demands, new ecological and efficient material joining and processing techniques have been developed, aiming to replace some of the commonly used industrial procedures. For aluminum alloys, friction-based joining and processing methods with a rotating tool element are presented in this paper, with potential applications in the aerospace industry. Data is provided on Friction Stir Welding (FSW), known for its ability to produce high-quality joints without compromising the structural integrity of materials, highlighting its advantages over traditional welding methods. The diversity of metallic materials, their characteristics and properties, as well as the technical requirements of different applications, have led to the development of variants of the friction stir welding process, one of which is Submerged (underwater) Friction Stir Welding (SFSW). Data on FSW and SFSW welding as well as several aluminum alloys that can be used in the aerospace industry are included in the paper. The paper also discusses ISIM's approaches in the FSW/SFSW domain for aluminum alloys EN AW 6082 and EN AW 7075 that are applicable to the aerospace industry because of their relevance and interest. The positive outcomes show that FSW and SFSW welding can be developed for a variety of metallic materials. The goal of ISIM’s current and future research is to apply the principles of the FSW/SFSW process to the FSP/SFSP processing of non-ferrous alloys, which can be used in a variety of industries.

Investigation of Microstructure and Mechanical Properties of Al Alloys Lap Joints by Friction Stir Welding

An experimental investigation on effect of friction stir lap welding (FSLW) process parameters on mechanical and microstructure of AA6082-O welds is presented. Three process parameters namely tool rotational speed (1000,1400 & 2000 rpm), tool shoulder diameter (18, 20 & 22 mm) and tool traverse speed (28, 56 & 80 mm/min) are considered. Experiments are planned as per L9 Taguchi array. Data are analyzed in terms of S/N ratio and Analysis of Variance (ANOVA). Tensile shear strength is observed in the range of 11.79 MPa to 29.23 MPa. It is observed that tool diameter and tool rotational speed are most significant factors affecting tensile shear strength. Optimum levels of process parameters (28 mm/min tool traverse speed, 18 mm tool diameter and 1400 rpm tool rotational speed) is decided based on analysis of experimental data. Using optimum process parameters for friction stir lap welding of Al alloys improved quality of welded joints can be made. Use of optimized parameters will improve the performance of the products in terms of durability and load carrying capacity.

Light metal alloys used in the aeronautical industry suitable for FSW welding/ FSP processing

This study presents light metal alloys used in the aeronautical industry, specifically focusing on their suitability for Friction Stir Welding (FSW) and Friction Stir Processing (FSP). These innovative techniques play an important role in improving the mechanical properties and performance of aluminum, magnesium, and titanium alloys, which are extensively utilized in aerospace applications due to their superior strength-to-weight ratios. FSW and FSP offer significant advantages in joining and processing materials, including enhanced weld integrity, defect reduction, and refined microstructural properties. The integration of light metal alloys by these methods within the aeronautical sector fosters the production of lighter and stronger structures, contributing to reduced fuel consumption and improved overall performance in aeronautical engineering.

Max-phase Ti3SiC2 and diverse nanoparticle reinforcements for enhancement of the mechanical, dynamic, and microstructural properties of AA5083 aluminum alloy via FSP

Abstract This study investigated the effects of max-phase Ti₃SiC₂ and other nanoparticle reinforcements (graphene, CNTs, and SiN) on the mechanical and dynamic properties of friction stir processed (FSPed) AA5083 aluminum composites. Microstructural analysis revealed the impact of these reinforcements on grain size. Dynamic properties were assessed using a free vibration impact test, while mechanical properties were measured through a compression test. Most composites showed enhancements in damping ratio and natural frequency compared to the base alloy, with the Ti₃SiC₂ leading to a substantial increase in natural frequency. The AA5083/max phase Ti3SiC2 composite demonstrated the most significant improvements across nearly all properties, notably enhancing stiffness (+7.35% in E), strength (+25.36% in yield strength), and vibration resistance (+5.83% in fₙ), while significantly reducing damping (−62.76% in ζ). In contrast, the friction stirred AA5083 offered moderate enhancements in strength (+17.86% in yield strength) and a slight increase in natural frequency (+2.00%) but did not significantly improve stiffness and actually increased damping. The base alloy AA5083 served as the baseline for comparison, exhibiting the lowest performance in all categories. The findings highlight the potential of FSP and reinforcement, especially Ti3SiC2, for tailoring the properties of AA5083 for enhanced performance in various applications. These findings emphasize the significance of customizing the reinforcement material to attain the intended mechanical characteristics in AA5083 composites.

Investigation of structure and properties of the welded joint obtained by friction stir welding of 1580 alloy hot-rolled sheets

Investigation of structure and properties of the welded joint obtained by friction stir welding of 1580 alloy hot-rolled sheets

Process Parameters and Tool Design in Friction Stir Extrusion: A Sustainable Recycling Technique

ABSTRACTFriction stir extrusion (FSE) is a versatile technique that plays a dual role in sustainable recycling and shaping of materials. This method involves a rotating mandrel and a fixed matrix within a mold, where compressed waste metal chips or primary bulk materials are introduced. The rotating mandrel exerts continuous axial pressure, generating frictional heat that softens and bonds the materials together. As the mandrel advances, the materials are reshaped and extruded through the cavity inside the mandrel or the space between the mandrel and the matrix, resulting in the desired product, such as wires or pipes. FSE finds applications in recycling machining wastes, improving powder metallurgy products, producing wire raw materials, creating structures with fine microstructures, and developing new alloys and composites. The resulting materials exhibit refined grains, leading to enhanced mechanical and metallurgical properties. This review article compiles experimental studies exploring the mechanical and microstructural characteristics of samples manufactured using FSE for recycling, reshaping, alloying, or bilayer production. Additionally, it discusses various tool, mold, and machine designs proposed by researchers. Beyond its unique properties, FSE is highlighted as an energy‐efficient, sustainable, and eco‐friendly process.

Failure Analysis of AA 7075 Joints Processed by FSW and SFSW

This paper presents a failure analysis of AA 7075 Aluminium 7075 joints processed by Friction Stir Welding (FSW) and Submerged Friction Stir Welding (SFSW) techniques. AA 7075 is a high-strength aluminium alloy commonly used in aerospace, automotive, and other industries due to its excellent mechanical properties. Understanding the failure mechanisms in these joining processes is essential for ensuring the structural integrity and reliability of AA 7075 joints. The study investigates the failures encountered in FSW and SFSW joints of AA 7075. Macroscopic and microscopic examinations are conducted to analyse the root causes of these failures. Macroscopic observations include visual inspection, dimensional measurements, and identification of fracture locations. Microscopic investigations utilize techniques scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) to examine the microstructure, fracture surfaces, and elemental composition of the failed joints. Based on the failure analysis findings, recommendations are provided to enhance the quality and reliability of AA 7075 joints processed by FSW and SFSW. The results of this failure analysis contribute to the understanding of AA 7075 joining processes using FSW and SFSW methods. By identifying the failure mechanisms and proposing preventive measures, this research aids in improving the quality and performance of AA 7075 joints, thereby ensuring the integrity and reliability of joined structures in industries that rely on aluminium alloys for critical applications.

Failure Analysis of Al 6082 Joints Processed by FSW and SFSW

This paper presents a failure analysis of Al 6082 joints processed by Friction Stir Welding (FSW) and Self-Reacting Friction Stir Welding (SFSW) techniques. Aluminium alloy Al 6082 is commonly used in structural and automotive applications due to its excellent strength, corrosion resistance, and weldability. The study focuses on investigating the failures encountered in FSW and SFSW joints of Al 6082. Macroscopic and microscopic examinations are conducted to analyse the root causes of these failures. Macroscopic observations include visual inspection, dimensional measurements, and identification of fracture locations. Microscopic investigations utilize techniques such as optical microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) to examine the microstructure, fracture surfaces, and elemental composition of the failed joints. The results of this failure analysis contribute to the understanding of Al 6082 joining processes using FSW and SFSW methods. By identifying the failure mechanisms and proposing preventive measures, this research aids in improving the quality and performance of Al 6082 joints, thereby ensuring the integrity and reliability of joined structures in industries that rely on aluminium alloys for critical applications.

Experimental investigation and parametric optimization of FSW of mineral-reinforced AA6061 matrix composite

Abstract In this work, rutile reinforced AA 6061 matrix composites were joined using friction stir welding and the process variables were optimized using Taguchi L27 orthogonal design of experiments. The rotational speed, axia force and tool tilt angle were the parameters taken into consideration. The optimum process variables were determined with reference to tensile strength, impact strength and hardness of the joint. The predicted optimal value of output responses were confirmed by conducting the confirmation run using optimum parameters. The optimal process variables combination values that resulted in improved mechanical properties were observed at a tool rotational speed of 1400 rpm, a tool tilt angle of 2 degree, and an axial force of 3KN. Scanning electron microscopy (SEM) analysis were used to probe the microstructures.

Refill Friction Stir Spot Welding of an Al-Li Alloy: The Effects of Rotating Speed and Welding Time on Joint Microstructure and Mechanical Properties

In this work, 2060 Al-Li alloy was joined by refill friction stir spot welding (RFSSW). The effects of the tool’s rotating speed and welding time on the microstructure and mechanical properties of the welded joints were studied. The results showed that joints without defects can be obtained within a wide range of welding parameters. Tiny voids were formed when using a low rotating speed of 1600 rpm, and incomplete refilling was obtained when using a short welding time of 1 s. Increasing the rotating speed from 1600 to 2000 rpm increased the grain size of the stir zone (SZ). When using a short welding time of 1 s, the grains of the SZ were not completely broken with high orientation differences in the grains. Higher hardness was obtained in the SZ when using a lower rotating speed and shorter welding time. Increasing the rotating speed increased the joint strength, while short and long welding times decreased the joint strength.

Comparative study on microstructure characteristics and mechanical properties of dissimilar friction stir welded aluminum alloy using single and double rotating shoulder tools

Comparative study on microstructure characteristics and mechanical properties of dissimilar friction stir welded aluminum alloy using single and double rotating shoulder tools