Friction Stud Welding Research Articles

Comparative Study of Friction Stir, Stud and Seam Welding of Aluminium Alloys Using Different Grades

Friction stud welding is an innovative and efficient welding process used to create strong and reliable bonds between studs or fasteners and workpieces, particularly in applications where rapid and secure fastening is critical. This welding technique involves generating friction and heat between the stud and workpiece to forge a strong joint. The process consists of several key steps, including preparation, rotation, weld formation, and cooling. Friction stud welding offers numerous advantages, such as speed, consistency, minimal distortion, and the elimination of the need for additional filler materials. It is widely employed in various industries, including construction, automotive, and aerospace, for applications ranging from structural steel connections to automotive component assembly. However, successful friction stud welding necessitates careful selection of materials, welding parameters, and skilled operators to ensure durable and dependable welded joints. This abstract provides a concise overview of the friction stud welding process and its essential features.

Sleeve friction stud welding towards formation and property

Sleeve friction stud welding (SFSW) was proposed to improve formation integrity and welding efficiency of stud joints. 18 mm diameter 5A06 stud and 15 mm thick 7A52 high-strength aluminum alloy were successfully joined at a time of 10 s. A uniform thickening joint with a chamfer was obtained, while flash defects in conventional welding were eliminated. The sleeve avoided the overflowing of plasticized materials, which facilitated material flow in the central of the joint corresponding to the taper stud, eliminating interfacial kissing-bond defects. The maximum tensile strength of SFSW joint reached 292 MPa, while fractured at the semi-hollow stud. SFSW has the potential to excellent joints with different sizes, offering a novel approach to advance of stud welding.

INVESTIGATION OF FRICTION PRESSURE EFFECT ON WELDING QUALITY IN FRICTION STUD WELDING PROCESS

The influence of friction pressure on welding quality when friction stud welding 1017 low carbon steel with AISI 304 austenitic stainless steel is investigated in this study. friction stud welding is employed in industrial applications instead of conventional welding processes Due to the friction welding process didn't need to reach the melting point of welded metals. Welding is performed on these dissimilar metals by utilizing a lathe machine with a load cell connected to a weight indicator and a manufacturing grip to fasten the plate at a rotating speed of 1600 RPM, a friction time of 20 seconds, and a friction pressure of (15, 20, and 25) MPa. After the welding procedure is completed, the specimens are subjected to tensile, torque, and hardness tests to evaluate the welding quality. In addition, optical microscope research was carried out to determine the microstructural aspects. The effect of friction pressure on welding quality was investigated based on the information generated from the results. The increase of friction pressure during the process from 15 MPa to 25 MPa leads to an increasing ultimate tensile strength from 203 MPa to 210 MPa approximately. Also, the torque values raised from 179 N.m to 198 N.m in the same case.

Investigation on Impact Strength of Friction Stud Welded AA6061-B4C Composite/AISI 1030 Steel Joints in Inert Gas Atmosphere

A more contemporary variation of the friction welding procedure, friction stud welding, is promising for military, space, automotive and naval applications. The joining of steel/aluminium matrix composite joints has been crucial in many of these contemporary applications. In all of these applications, the strength of the dissimilar joint is a critical consideration. Heat-affected zones arise because of the heterogeneous temperature distribution and change in thermal characteristics, which weaken the strength of the joints between different materials. The presence of oxygen in the weld interfacial region of the dissimilar joint is detrimental to its strength and integrity. Hence, a new method that can strengthen the dissimilar joint is adopted in the current work. In the friction stud-welding machine, an additional set up is integrated for providing an inert atmospheric condition during the welding process. Microstructural analysis shows that an inert atmosphere is helpful to get rid of oxygen at the interface and it increases joint efficiency. The results show that the impact strength of AA6061-B4C composite/AISI 1030 steel joints tends to increase in the argon inert atmosphere from 14% to 28%.

INVESTIGATION ON THE THERMAL BEHAVIOR OF FRICTION STUD WELDING OF DISSIMILAR ALUMINUM/MILD STEEL JOINTS

Friction stud welding process is a suitable candidate in joining stud fasteners for steel structure buildings, military vehicles, automobiles, aircraft, ocean liners, bridges, ship buildings, etc., The peak temperature for welding is achieved by converting mechanical energy to thermal energy at the sample interface without the use of electric energy from other sources because it is a solid-state process. The study of the thermal behavior of different metals during friction stud welding is very important since it is a thermal energy process. However, there is no good thermal model for the friction stud welding process. In this work, the generation of heat flux at the interfacial area of two distinct metals, namely aluminum and mild steel, is calculated using a mathematical model. The temperature at the interfacial region, which plays a significant role in the quality and strength of the weld component, is particularly focused on experimentation and analytical modeling. In the experimentation, a noncontact type infrared thermometer is used to measure temperature directly. The temperature profile was determined by the finite difference method based on thermal resistance and capacitance formulation at transient conditions. The obtained mathematical results are compared with the experimental results at the distance of 5 and 10[Formula: see text]mm from the welded interface. The computed temperature profile is in good agreement with the experimental data on the heating side and with a minimum degree of deviation in the cooling part. The maximum percentage of error for the 5[Formula: see text]mm interface is 3.349 and for the 10[Formula: see text]mm interface is 2.857. This deviation is due to the zero-axial shortening assumption in the analytical model. Besides, the temperature characteristics of the welded are analyzed at various time increments by numerical simulation. As a result, the predicted temperature is more on the aluminum side compared to the mild steel due to a change in thermal properties. This proposed thermal model would be helpful to improve the design and manufacture of welding machines.

Stud shape and joint strength for low carbon steel joints fabricated by friction stud welding with low load force requirement

This paper describes the stud shape and joint strength of low carbon steel joints fabricated by friction stud welding with low load force requirement. To reduce the load force during the welding process, the stud side with the circular hole at the weld faying surface part was used. The outer diameter of a cylindrically shaped stud side had 12.0 mm and that was welded to the circular solid bar with a diameter of 24.0 mm as the work side. The joint was made with a friction speed of 27.5 rps, a friction pressure of 60 MPa, and a forge pressure of 60 MPa, which was determined as the low force condition for obtaining good joint in the previous study. When joints were made by a cylindrically shaped stud with a hole diameter of 6.0 mm and its depth of 0.5 mm, all joints at a friction time of 0.6 s, i.e. the friction torque reached to the initial peak, had the same tensile strength as that of the base metal with the base metal fracture. All joints with flash from the initial weld interface had the fracture on the base metal, the bend ductility of over 15° with no cracking at the initial weld interface through an impact shock bending test, and a high fatigue strength of the base metal. That is, the sound joint could be successfully achieved, and that could be obtained with the same friction stud welding condition of the circularly shaped solid stud. As a conclusion, the joining technique for the friction stud welding method with low load force requirement was proposed in accordance with using a cylindrically shaped stud that has the circular hole with the shallow depth at the weld faying surface part.

Probing the Anti-Corrosion Behavior of X65 Steel Underwater FSW Joint in Simulated Seawater

To detect the corrosion resistance of a friction stud welding (FSW) joint in simulated seawater (a 3.5 wt% NaCl solution), the pulse electrochemical deposition method was used for electroplating Ni coating with different duty ratios (50%, 80%, and 100%) on the surface of FSW joint. The microstructure and surface structure of the coating were observed by micro-spectroscopy and other characterization methods. The corrosion behavior of the coating was analyzed by means of macroscopic electrochemical testing. The local corrosion law of joint surface and coating surface defects were innovatively explored by using micro-zone electrochemical scanning system. The coating characterization results showed that, as the duty ratio continues to increase, the coating surface becomes denser and smoother, and the corrosion products such as Fe2O3, Fe3O4, and FeOOH are generated. The results of macroscopic electrochemical experiment indicated that the coating with 100% duty ratio has the lowest corrosion current density and the maximum polarization resistance. The scanning vibrating electrode technique results showed that the corrosion current density in the defect area is higher than that in the coating area, and the maximum corrosion current density decreases with the increase of duty ratio. The localized electrochemical impedance spectroscopy results indicated that the localized impedance at the welded zone was the largest, and with the increase of the pulse duty ratio, the impedance diffusion in the defect area was decreasing.

Methods for improving joint strength of friction stud welded AA5083 alloy joints

The joint strength and its improvement of AA5083 Al alloy joints fabricated by friction stud welding method were investigated. The diameter of the work and stud side specimens were 32.0 mm and 12.8 mm, respectively, and those were friction welded. The appropriate welding condition for obtaining high tensile strength was established as follows: a friction speed of 17.5 s−1, a friction pressure of 80 MPa, a friction time of 1.6 s, and a forge pressure of 360 MPa. However, all joints fractured between the initial weld interface and the work or stud sides, i.e. the fracture did not occur in the base metal. It could be considered that the initial oxide film on the weld faying surface of the work side was not exhausted as the flash during the welding process. To obtain the joint having the fracture in the base metal, the suitable shape at the weld faying portion of the work side specimen was suggested as the groove shape. The inner diameter of the groove corresponded to the same diameter of the stud side, and that had a groove width of 3.0 mm with a groove depth of 1.0 mm. As a conclusion, AA5083 friction stud welded joint, which had the tensile strength of the base metal and the fracture in the base metal, could make with the appropriate welding condition. Furthermore, the weld faying portion at the work side should be in the suitable shape that urges the extrusion of the flash from this side.

Stud Shape and Joint Strength for Low Carbon Steel Joints fabricated by Friction Stud Welding with Low Load Force Requirement

Stud Shape and Joint Strength for Low Carbon Steel Joints fabricated by Friction Stud Welding with Low Load Force Requirement

Numerical simulation of axial shortening distance in friction stud welding of aluminium/mild steel joints

The execution of numerical simulation in friction-stud welding technique comprises of complex steps involving the thermo-mechanical phenomena along with metallurgical modifications within the materials. It is explored that welded component’s mechanical properties mainly depend on the inter-metallic bonding between the dissimilar metals and hence axial shortening distance plays a key role in the determination of the strength of the weld. Owing to its significance, numerical model is established based on finite element to predict the actual axial shortening distance accurately. The validation of the numerical model was accomplished through comparing the numerical predicted data with actual experimental data. Through this validation, axial shortening distance can be predicted for aluminium and mild steel combination of dissimilar material at the enhanced level of accuracy. These validation inferences are essential sources for ensuring the quality level at the region of welding. In addition to S that, numerical simulation results related to stress, thermal gradient plots, strain and thermal flux are furnished in the present work.

Investigation on friction stud welded AMC/AISI 304 steel joints with ceramic intercoating

Friction stud welding, a recent variant of friction welding process, is ideally suited for naval applications, short-term emergency repairs, submarine rescue, aerospace applications and automotive applications. In all these critical applications, there is a need for joining of dissimilar materials in general and aluminium matrix composites/steel joints in particular as in the case of recent aerospace and automotive applications. The strength of the dissimilar joint is a major concern in all these applications. Due to the variation in thermal properties and inhomogeneous temperature distribution, heat-affected zones are formed that lead to deterioration in strength in the dissimilar joints. In the present work, a new procedure is disclosed that can increase the strength of the dissimilar joint. The design of the specimen is modified and ceramic slurry is introduced at the interface in order to achieve increase in joint efficiency and higher joint strength.

Process Capability & Fascinating applications of Friction Stud welding

In earlier days, welding only involves joining two metals of same kind and dissimilar metals were usually joined by fasteners. Friction Stud welding is a true engineering marvel of making welds between dissimilar metals without any melting or fillers involved. The friction stud welding doesn’t involve heat generation from electricity and it is purely based on friction. Besides these facts the friction stud welding has numerous advantage and applications. This paper focuses on the process of stud welding, application and its limitations.

Microstructure, Chemical Composition and Local Corrosion Behavior of Friction Stud Welding Joint

In this paper, X65 base metal and stud were joined by friction stud welding technology. Scanning vibrating electrode technique (SVET) and localized electrochemical impedance spectroscopy (LEIS) were performed to investigate localized corrosion behaviors of the welded joint. Scanning electron microscope (SEM), metallographic microscope and micro hardness tester were used to observe the microstructure and the hardness of the welded sample. Raman spectrometer and energy dispersive spectrometer (EDS) were used to determine the composition of the weldment before and after corrosion, respectively. The results show that the welded zone has the maximum micro-hardness and the densest microstructure. And the α-Fe2O3 and Fe3O4 were determined in the welded zone. The SVET and LEIS data indicate that the welded zone has the lowest current density and the largest impedance, this may due to the presence of iron oxides and the densest microstructure in the welded zone, showing the best corrosion resistance. The resistance between microstructure, micro-hardness, chemical composition and local electrochemical behavior were discussed. Keywords: Friction stud welding; Raman; SVET; LEIS; X65 steel

Regression Modelling of Joining Aluminium Studs to Steel with AA 1100 Interlayer

Recently, there is a steep increase in the requirement for aluminium-steel joints in several automotive and structural applications. But joining of dissimilar metals possesses unique challenges. To overcome these issues, AA 1100 interlayer has been proposed in the friction stud welding of AISI 1030/AA 1050 joints. In the present work, it is found that the use of interlayer not only enhances the joint strength but also inhibits the formation of flash and thereby reduces the consumption of base metals. Applying full factorial design, experiments were conducted to study the influence of interlayer thickness along with other parameters such as rotational speed, friction time and friction pressure on the strength of joint. SEM evaluation on the fractured surface of the specimens was carried out. Ductile mode fracture with dimples observed with 0.95 mm interlayer. Microvoids absorb a lot of energy, and the toughness is high. Hence, the dissimilar joint made using 0.95 mm interlayer have high joint strength. Microhardness measurement across the interfacial region shows increased value near the weld line due to increased plastic deformation. Finally, regression analysis is carried out and an empirical relation has been developed to predict impact strength and axial shortening length in terms of other parameters.

Optimization of friction stud welding process parameters by integrated Grey-Fuzzy logic approach

In this work, an integrated grey fuzzy logic technique is employed for solving the multi objective function of friction stud welding machine process parameters. This technique converts the multi-objectives into a grey fuzzy reasoning grade. According to the grey fuzzy reasoning grade, an optimal combination of process parameters is concluded. Here, Taguchi L9 orthogonal array is used to design the experiments. The objective of this work is to maximize impact strength and minimize metal loss during the joining of AA 6063 and AISI 1030 steel. Rotational speed, friction time, and friction pressure are considered as the input process parameters. The outcomes of the confirmation test show that good joining strength is accomplished by the optimal level of process parameters.

Effect of friction welding conditions on joint properties of austenitic stainless steel joints by friction stud welding

ABSTRACTThis study focuses on the opening mode of induction bends; this mode represents the deformation outside a bend. Bending experiments on induction bends are shown and the manner of failure of these bends was investigated. Ruptures occur at the intrados of the bends, which undergo tensile stress, and accompany the local reduction in wall thickness, i.e. necking that indicates strain localization. By implementing finite element analysis (FEA), it was shown that the rupture is dominated not by the fracture criterion of material but by the initiation of strain localization that is a deformation characteristic of the material. These ruptures are due to the rapid increase in local strain after the initiation of strain localization and suddenly reach the fracture criterion. For the evaluation of the deformability of the bends, a method based on FEA that can predict the displacement at the rupture is proposed. We show that the yield surface shape and the true stress–strain relationship after uniform elongation have to be defined on the basis of the actual properties of the bend material. The von Mises yield criterion, which is commonly used in cases of elastic–plastic FEA, could not predict the rupture and overestimated the deformability. In contrast, a yield surface obtained by performing tensile tests on a biaxial specimen could predict the rupture. The prediction of the rupture was accomplished by an inverse calibration method that determined the true stress–strain relationship after uniform elongation.

Microstructure, Chemical Composition and Local Corrosion Behavior of a Friction Stud Welding Joint

In this paper, friction stud welding technology was used to join a stud and base metal, which were composed of X65 steel. The scanning vibrating electrode technique (SVET) and localized electrochemical impedance spectroscopy (LEIS) were used to investigate the localized corrosion behaviors of the welded joint. Scanning electron microscopy, metallographic microscopy and a micro-hardness tester were used to observe the microstructure and measure the hardness of the welded sample. Raman spectrometry and energy-dispersive spectrometry were used to measure the composition of the weldment before and after corrosion, respectively. The results show that there are the maximum micro-hardness and the densest microstructure in the welded zone compared with the other zones. In addition, α-Fe2O3 and Fe3O4 are present in the welded zone. The SVET and LEIS data indicate that the welded zone has the lowest current density and the largest impedance due to the presence of iron oxides and the densest microstructure, thus showing the excellent corrosion resistance. The relationship among microstructure, micro-hardness, chemical composition and local electrochemical behavior was discussed.

Joining of hybrid AA6063-6SiC p -3Gr p composite and AISI 1030 steel by friction welding

Abstract Joining of metals and aluminium hybrid metal matrix composites has significant applications in aviation, ship building and automotive industries. In the present work, investigation is carried out on Friction Welding of AISI 1030 steel and hybrid AA6063-6SiC p -3Gr p composite, that are difficult to weld by fusion welding technique. Silicon carbide and graphite particle reinforced AA6063 matrix hybrid composite was developed successfully using stir casting method and the joining feasibility of AISI1030 steel with AA6063-6SiC p -3Gr p hybrid composite was tried out by friction stud welding technique. During friction stage of welding process, the particulates (SiC & Graphite) used for reinforcement, tend to increase the viscosity and lead to improper mixing of matrix and reinforcement. This eventually results in lower strength in dissimilar joints. To overcome this difficulty AA1100 interlayer is used while joining hybrid composite to AISI 1030 steel. Experimentation was carried out using Taguchi based design of experiments (DOE) technique. Multiple regression methods were applied to understand the relationship between process parameters of the friction stud welding process. Micro structural examination reveals three separate zones namely fully plasticized zone, partially deformed zone and unaffected base material zone. Ultra fine dynamically recrystallized grains of about 341 nm were observed at the fully plasticized zone. EDX analysis confirms the presence of intermetallic compound Fe 2 Al 5 at the joint interface. According to the experimental analysis using DOE, rotational speed and interlayer sheet thickness contribute about 39% and 36% respectively in determining the impact strength of the welded joints. It is found that joining with 0.5 mm interlayer sheet provides efficient joints. Developed regression model could be used to predict the axial shortening distance and impact strength of the welded joint with reasonable accuracy.

摩擦スタッド接合したオーステナイト系ステンレス鋼継手の継手特性に及ぼす圧接条件の影響

摩擦スタッド接合したオーステナイト系ステンレス鋼継手の継手特性に及ぼす圧接条件の影響

Underwater Friction Stud Welding Optimal Parameter Estimation: Engineering Robust Design Based Approach

Underwater friction stud welding (FRSW) without a shroud around the stud requires controlling welding parameters to achieve optimal joint strength. A hydraulic FRSW unit has been designed and fabricated to perform FRSW without a shroud via a remotely operated underwater vehicle (ROV). An experimental study has been initiated to investigate the optimal FRSW parameter combinations and corresponding values leading to optimal ultimate tensile load capacity (UTLC) values in the welded joint. The engineering robust design (ERD) approach has been deployed to run the experiment. Each weld has been made with a S355 M12 stud on S355 structural steel plate. This paper discusses the experimental approach, results and conclusions reached in the parameter evaluation, estimation, and experimentation.