Friction Welding Research Articles

Thermomechanical and microstructural simulation of rotary friction welding process of Inconel718 alloy using the finite element method

Thermomechanical and microstructural simulation of rotary friction welding process of Inconel718 alloy using the finite element method

Intelligent optimization of non-rigidly supported stationary shoulder friction stir welding parameters

During the online welding of railway aluminum alloy trucks using fixed shoulder stirring friction welding technology, defects such as flying edges, cracks, and tunnels may occasionally occur due to poor coordination of the welding process parameters. This inconsistency can compromise the success rate of the welding. To enhance the quality and efficiency of the welding repairs, an optimization of the welding process parameters of the developed equipment was undertaken. An intelligent prediction model for welding parameters was established based on the BSO-BP neural network. The model was trained with 17 sets of authentic welding data, and its accuracy was validated through a comparison of predictive outputs with actual welding outcomes. The BSO-BP neural network demonstrated a maximum error of 1.85% and a relative error of 1.27%, showing a marked improvement over traditional BP neural network predictions. Utilize the optimized welding process parameters obtained from a trained predictive model to conduct welding experiments under actual working conditions. During the experiment, the deformation of the test plates was minimal. The resulting welds were smooth, free of defects such as flash and grooves, and the overall welding quality was good. The tensile strength of the welds, at 262.95 MPa, was close to the predicted results and reached 78.49% of the base material’s tensile strength. In the microstructure of the weld, sporadically distributed dimples of varying sizes can be observed, indicating the presence of second phase particles which contribute to enhancing the tensile strength of the weld, thereby meeting the strength requirements of the aluminum alloy car body. The parameter optimization method used has certain reference value and can provide guidance for similar research.

C.P titanium/Ti–6Al–4V joint by spark plasma welding: Microstructure and mechanical properties

The welding ability of Ti–6Al–4V alloy is weak due to their two-phase microstructure. On the other hand, friction welding methods lead to significant microstructural changes. In this research, for the first time, pure titanium was successfully joined to the Ti–6Al–4V alloy, without any change in the microstructure and mechanical properties of both alloys, by applying the SPW method. Further, the effects of temperature, pressure, and time of the SPW process on the microstructure and mechanical properties of commercial pure (C.P) titanium joined to the Ti–6Al–4V alloy were investigated. The results indicated that the effect of temperature and pressure on the SPW process was greater than that of time. Further, mechanical properties investigations showed that the yield strength of the joint interface was larger than that of the substrate metal, following which necking and fracture occurred in the pure titanium substrate metal. The alloy (Ti–Ti64) bonded at 800 °C, with a time of 10 min and pressure of 20 MPa, exhibited the superior bonding of 7–9 μm interface thickness, and excellent tensile strength (534 ± 13 MPa) and Vickers micro-hardness (190 ± 5 HV0.1). Investigation of the effect of pressure (normal stress) also showed that with an increase in pressure, because of the reduction of the chemical potential of diffusing species, the joint temperature would drop, and the joint could be created at a temperature below 800 °C.

The Experimental and FEM Studies of Friction Welding Process of Tungsten Heavy Alloy with Aluminium Alloy

Experimental and finite element studies of the rotary friction welding (RFW) process of tungsten heavy alloy (THA) with aluminium alloy 5XXX series are presented. A 2.5D torsion simulation model including the circumferential effects was developed in this study. The temperature distributions, effective stress, flash dimensions and axial shortening were calculated on un-rotated friction welding aluminium parts. The peak temperatures were measured both in the axis and at the half-radius of the specimen. The maximum interface temperature of 581 °C for the friction weld was below the melting temperature of the aluminium alloy. The experimental and numerical results of the temperature and final weld geometries show good agreement between them. The results indicate very small deviations of 4.45%, 2.96%, and 2.34% on the flash width, flash height and axial shortening of friction welds.

Non-synchronous deformation under shot peening post-treatment of SUS304 bar-plate rotary friction weld generates non-monotonic evolution on material and fatigue property

Shot peening post-treatment was conducted at SUS304 austenite steel bar-plate rotary friction welding joint with fatigue property deterioration from welding flash. along the shotting intensity increasing, non-synchronous deformation of the plate and flash resulted in non-monotonically evolution of local microstructure, residual stresses, and make the fatigue life increased to flash-removed joint level.

The effect of inclusions and pores on creep crack propagation of linear friction welded joints of GH4169 superalloy

Superalloy has become the key material in components of blisks for aero-engines produced by linear friction welding. However, during the long-term service of the blisks, stress rupture occurs on the blisk under long-term creep. In this study, the linear friction welded joints of GH4169 superalloy were studied with experiments and numerical simulation. The Sin-Hyperbolic creep-damage constitutive model was established. Based on the compact tension specimen model, the numerical simulation of crack propagation was carried out, analyzing the effect of defects in linear friction welded joints such as cracks, inclusions, and pores on creep crack propagation. Results show that inclusions have an impact on the deflection and promotion of creep crack propagation. The maximum values of crack propagation rate can be observed when radius is 0.03 mm for circular inclusions and length-to-diameter ratio is 3 for elliptical inclusions, respectively. When the transverse distance between the center of the pore and the crack tip is 0.6 mm, the effect on crack propagation is the most significant, with the crack deflecting and expanding towards the direction of the pore. The effect of elliptical pores on creep crack propagation is more significant than that of circular pores. When the length-to-diameter ratio is 3, cracks have initiated firstly on both sides of elliptical pores. When the angle between the pore and the prefabricated crack is 0°, the elliptical pore has the greatest deflection effect on the creep crack. Overall, the effect of pores on creep crack propagation is stronger than that of inclusions.

Microstructural Characterization and Corrosion Behavior of Similar and Dissimilar Welded Advanced High-Strength Steels (AHSS) by Rotary Friction Welding.

Advanced high-strength steels (AHSSs) are designed for meeting strict requirements, especially in the automotive industry, as a means to directly influence the reduction in the carbon footprint. As rotary friction welding (RFW) has many important advantages over other welding technologies, it plays an important role in the automotive sector. On the above basis, in this work, combinations of the first (complex phase (CP)), second (TWIP (TW)), and third (quenched and partitioned (Q&P)) generations of similar and dissimilar high-alloyed advanced steels have been joined by the RFW process. Having a specific microstructure, rods of CP/CP, Q&P/Q&P, CP/TW, and Q&P/TW steels were welded by employing a homemade adaptation machine under fixed parameters. Microstructural characterization has allowed us to corroborate the metallic bonding of all the tested advanced steels and to identify the different zones formed after welding. Results indicate that the welding zone widens in the center of the workpiece, and under the current friction action, the intermixing region shows the redistribution of solute elements, mostly in the dissimilarly welded steels. Furthermore, because of their complex chemistry and the different mechanical properties of the used steels, dissimilarly welded steels present the most noticeable differences in hardness. The TWIP steel has the lower hardness values, whilst the CP and Q&P steels have the higher ones. As a direct effect of the viscoplastic behavior of the steels established by the thermomechanical processing, interlayers and oxidation products were identified, as well as some typical RFW defects. The electrochemical response of the welded steels has shown that the compositional and microstructural condition mostly affect the corrosion trend. This means that the dissimilarly welded steels are more susceptible to corrosion, especially at the TWIP-steel interface, which is attributed to the energy that is stored in the distorted microstructure of each steel plate as a consequence of the thermomechanical processing during RFW.

Thermal-Mechanical and Microstructural Simulation of Rotary Friction Welding Processes by Using Finite Element Method.

Rotary friction welding is one of the most crucial techniques for joining different parts in advanced industries. Experimentally measuring the history of thermomechanical and microstructural parameters of this process can be a significant challenge and incurs high costs. To address these challenges, the finite element method was used to simulate thermomechanical and microstructural aspects of the welding of identical superalloy Inconel 718 tubes. Numerical simulation results were used to compute essential mechanical and metallurgical parameters such as temperature, strain, strain rate, volume fraction of dynamic recrystallization, and grain size distribution. These parameters were subsequently verified using experimental test results. The Johnson-Avrami model was utilized in the microstructural simulation to convert thermomechanical parameters into metallurgical factors, employing a FORTRAN subroutine. The calculated thickness of the recrystallization zone in the wall was 480 and 850 μm at the tube wall's center and edge, respectively. These values were reported from experimental measurements as 500 and 800 μm, respectively. The predicted grain size changes from the center to the edge of the wall thickness, near the weld interface, ranged from 2.07 to 2.15 μm, comparable to the experimental measurements ranging from 1.9 to 2.2 μm. Various curves are also presented to explore the correlation between thermomechanical and microstructural parameters, with the experimental results revealing predictable microstructure evolutions correlated with thermomechanical changes.

The microstructural morphology of transformed α induced by β fiber texture in a dissimilar inertia friction weld between near-α and α+β titanium alloys

The microstructure and texture features of the dissimilar inertia friction welded (IFW) joint of Ti65 titanium alloy to TC25G titanium alloy were characterized. The β textures in dynamic recrystallization zone (DRZ) produced by severe hot shear deformation were dominated by the bcc D2 (11-2)[111] shear texture for both the Ti65 and the TC25G alloys. The variant selection occurred during the β α phase transformation at the final cooling stage, in which higher fraction of α variants with misorientation of [−10 5 5 3]/63.26° formed. The triangular configuration structures were frequently observed in the interior of the β grains in DRZ, which was resulted from the variant selection occurring in microregion. The formation of triangular configurations was also favored naturally by the <111>bcc β fiber texture.

An Analytical Model of Material Deformation During Friction Welding of Alloy 718

A new model of the material flow in rotary friction welding of tubes is proposed. The material flow proposed is based on 3D microcomputer tomography scans of welds performed with tungsten tracers. The tracers indicate a bifurcation of flow into two deformation paths. The material in Path 1 interacts with the weld interface and exhibits large azimuthal flow. The material in Path 2 transitions from axial to primarily radial flow with little or no azimuthal flow. The directional transition in this path is compared to orthogonal machining and equal channel angular pressing. The process to estimate the variables needed to calculate strain and strain rates using the equations from orthogonal machining and equal channel angular pressing is defined. Strain and strain rate in Path 2 are dependent upon feed rate and upset and decrease throughout the welding process. The strain rate is higher than previously reported for rotary friction welding as a result of the deformation model proposed.

Microstructure and Mechanical Properties of IN690 Ni-Based Alloy/316LN Stainless-Steel Dissimilar Ring Joint Welded by Inertia Friction Welding.

Inertia friction welding (IFW) was used to join large-diameter hollow bars made of Inconel 690 and 316LN successfully. The interfacial characteristics, microstructure, mechanical properties and fracture mechanism of welded joints under different process parameters were investigated. The results indicated that a joining mechanism with mechanical interlocking and metallurgical bonding was found in IFW joints. There was a significant mechanical mixing zone at the welding interface. The elemental diffusion layer was found in the "wrinkles" of the mechanical mixing zone. A tiny quantity of C elements accumulated on the friction and secondary friction surfaces. The tensile strength and impact toughness of the joints increased with the total welding energy input. Increasing the friction pressure could make the grain in all parts of the joint uniformly refined, thus enhancing the mechanical properties of welded joints. The maximum tensile strength and impact toughness of the welded joint were 639 MPa and 146 J/cm2, reaching 94% and 68% of that for Inconel 690, respectively, when the flywheel was initially set at 760 rpm, 200 MPa for friction pressure, and 388 kg/m2 for rotary inertia. Due to the Kirkendall effect in the welded joint, superior metallurgical bonding was at the welding interface close to the Inconel 690 side compared to the 316LN side.

APPLICATION OF FRICTION WELDING FOR PUMP DESIGN AND MANUFACTURING: A COMPREHENSIVE REVIEW

The discussion regarding the balance between economical and performance for the pump design and manufacturing has been increasing in recent years. Of many intelligent innovations, the use of less costly materials for pump shaft is an interesting solution for the pump design. This solution can also be achieved by selecting less costly materials made from metal. Then, the less costly metal connected to electrical motor is joined with a more costly metal connected to the pump. Since both metals can be difference ones, an advance welding process to join both metals is then required. The friction welding process is expected to fulfill this requirement. In the friction welding, heat is generated during friction between these two dissimilar metals. The generated heat should achieve particular temperatures so that the two dissimilar metals can be joined. There are three types of friction welding, e.g. the stir friction welding, the linear friction welding and the continuous drive friction welding, which can be selected to join these two dissimilar metals. This paper is based on the authors’ experience and literature review to discuss the application of friction welding for the pump design and manufacturing.

Quasi-equal strength and toughness matching rail steel joint obtained via friction welding below Ac1 temperature

U75V rail steel rods underwent continuous-drive friction welding (CDFW). Joint properties were evaluated through microstructural analysis and mechanical testing (tensile, impact, and microhardness). The thermo-mechanical behaviour of the CDFW process was simulated by the finite element method, while a computed continuous cooling transformation diagram was used to predict phase transformation, microstructures, and hardness variations. By reducing the spindle speed to 1000 r/min, the peak temperature in the weld centre zone (WCZ) remained below Ac1. Microstructures in WCZ exhibited a high density of geometrically necessary dislocations. The joints demonstrated comparable tensile strength, impact toughness, and microhardness to BM, with underlying mechanisms elucidated. This study showcases CDFW's potential in achieving rail steel joints with quasi-equal strength and toughness to the BM.

Preliminary study on effect of inertia and continuous friction welding on mechanical properties of SS 316-Zn alloys friction welded joint

The effect of inertial friction welding and continuous drive friction welding in joining SS 316 with Zn alloy is discussed in this article. Scanning electron microscopy was utilized to investigate the microstructure of the welding interaction. Energy-dispersive spectroscopy was utilized to identify the chemical composition of the element distribution at the interface. The findings reveal that a continuous drive friction welding process may produce SS 316 welded joints with Zn alloy. With a friction time of 35 s, the joint's tensile strength may reach 60 MPa. During the tensile test, all friction-welded samples failed at the interface. The fracture surface shows an almost flat surface and is not fibrous or brittle. Meanwhile, a new reaction layer from the intermetallic compound layer is not formed at the joint interface. The decrease in hardness in Zn alloys is due to the thermal softening effect caused by continuous heat from friction.

Rotary friction welding of X70 steel to duplex stainless steel

The objective of this research work is to present the mechanism of rotary friction welding of two dissimilar steels (X70 steel and duplex stainless steel). The selected rotational speed was maintained during the welding process. The welded sample was characterized by optical microscopy and hardness measurements. The welding sequence was presented. The duration and the mechanism of different welding stages have been determined. Optical observation revealed distinct zones in the welded joint. The Vickers hardness profile showed the difference in hardness across the welded joint.

Underwater Friction Welding of Low Carbon Steel

In this study, an attempt was made to obtain a welded joint from the underwater friction welding (UFW) process. The workpiece material used in this experiment was AISI 1018 low carbon steel. The experiment was carried out on a friction welding machine which was designed and manufactured for this purpose. The UFW process was carried out by varying the spindle rotation used to rotate one of the workpieces. The friction force was kept constant. The quality of the welded joints resulting from UFW was determined by measuring the misalignment that occurs in the weld joint, the macro and micro structures formed, as well as the mechanical properties of the welded joint. For comparison, friction welding in air (FW) was also carried out. The results obtained indicate that low spindle rotation results in high misalignment of the welded joint between the two workpieces. During the UFW process, rapid cooling occurs so that the microstructure of the weld metal, TMAZ and HAZ is dominated by a fine pearlite phase so that the hardness and strength of the weld joint are higher than those produced by FW process in air.

Value retention using remanufacturing: A case study on part and process down selection for wind turbine applications

As a key component of a circular economy, remanufacturing is gaining popularity across various sectors. This paper focuses on the wind energy sector, a major player in renewable technologies, which is gradually recognizing its increasing resource-intensive material usage. We present a case study outlining a method for selecting parts from an industrial supply chain partner’s inventory. This strategy is further employed to streamline the manufacturing processes for the chosen part. We utilized the Weighted Sum method, a multi-criteria decision-making strategy, in both instances. We discuss how expertise of process specialists and multi-criteria decision-making techniques could be synthesised for adopting a remanufacturing approach. Data from the commercial partners was collected and any identifying information was stripped. From this, we discovered that the Yaw gear pinion shaft is the top candidate for remanufacturing due to its high commercial value. After comparing various additive manufacturing technologies, Arc Directed Energy Deposition stands out as the best fit for remanufacturing this particular pinion shaft. Although our initial aim was to consider additive manufacturing technologies as solutions for remanufacturing, we show how even conventional manufacturing processes, such as friction welding, could emerge as strong contenders.

Joint Properties of Al-11%Zn-3%Mg-1.4%Cu Alloy by Friction Welding and the Effect of Heat Treatment

Joint Properties of Al-11%Zn-3%Mg-1.4%Cu Alloy by Friction Welding and the Effect of Heat Treatment

A LOCALIZED MESHLESS METHOD FOR TRANSIENT HEAT CONDUCTION WITH APPLICATIONS

The localized radial basis function (RBF) meshless approach is well suited for modeling transient heat conduction. The advantages of meshless methods, such as ease of discretization, are well known. However, there are still few examples of the method extended to three-dimensional (3D) transient heat conduction for geometries of practical engineering importance; in particular, with respect to graphics processing units (GPUs). In this study, we investigated the localized RBF meshless method in 3D transient heat conduction and explored its application for GPUs. Numerical examples are provided with an application to modeling chip cooling and friction welding.

Evaluation of efficiency of rotary friction welding in obtaining joints from corrosion and heat resistant steel

The efficiency of using rotary friction welding in obtaining joints from 20Cr13 steel has been evaluated. For this purpose, test samples with welded joint and from the base metal were made, and then microstructure studies and tensile tests were carried out. As part of the microstructure study, the structure of the welded joint metal and base metal was determined. As a result of tensile tests, the tensile strength, relative elongation after rupture, and fracture area were determined for the base metal and welded joint specimens. These tests have shown that friction welding can produce joints without the use of heating during welding.