Friction Welding Research Articles

A Study on Friction Welding by Use of an Automatic Lathe

A Study on Friction Welding by Use of an Automatic Lathe

Analysis of FSW welding parameters on mechanical welding properties in aluminum alloy AA 5083 plates using different tool geometries

Friction welding is based on a rotating tool that penetrates the line of union of the previously fixed and pressed pieces and moves along this line. It is a process of joining materials at low temperatures, in the solid state of metals, below their melting point. The heat generated by the friction of the tool at high rotation further dilutes the base material and flows towards the center of the tool, causing mechanical mixing, the shoulder of which causes the final stage of this material, already cooled. This article proposes to study the influence of the different parameters of FSW welding on the thermal characteristics of weld joints in aluminum and magnesium alloys, numerically. The simulation results confirmed that the temperature distribution is high from shoulder towards the borders of the parts and it was symmetrical with respect to the middle plane. The calculated maximum temperatures for magnesium and aluminum were 843.7 K & 702 K, respectively.

Development of equipment for carrying out torsion tests on AISI 4340 shaft

In the last 5 years, some companies in the midwest of Santa Catarina have started to apply different technologies in the manufacture of mechanical components, for example, friction welding of the shafts in the rotors of hydraulic pumps. To guarantee the quality of welded rotors, it is essential to test the mechanical assembly against the torsion test. The present study presents the development of the mechanical design of equipment to perform the torsion test, according to the specificity of local industrial applications. As results obtained, it was observed that the structure of the equipment is capable of resisting efforts during the torsion test. The secondary reducer gear shafts are robust against the torque calculated for fracture of the specimen according to ASTM A938. The gears designed for the external speed reducer also bear the stresses. The calculations carried out according to the bibliography indicated that the designed equipment has a maximum torque of 3500 Nm.

Friction welding process with SFPC consumable pin applied on stainless steel duplex SAF 2205

The objective of this work is to investigate the use of Friction Hydro Pillar Processing (FHPP), in the Duplex Stainless Steel- Sandvik Austenite Ferrite 2205 (AID SAF 2205), with low Axial Force of application and to qualify it in a similar way to repairs by conventional welding processes, through standard tests foreseen in norms. In addition, it is intended to go beyond conventional tests and bring new information about precipitated phases during processing, their consequences on microstructural evaluation and corrosion performance. Through the FHPP there are the advantages of: being able to repair the structure with the plant and/or the equipment in operation, as it does not involve melting the material, thus allowing a low structural distortion in addition to being a typically surgical type of repair where little material needs to be removed to perform the repair.

Investigation of Friction Welding Properties of Steels with Different Chemical and Mechanical Properties Used in the Oil and Gas Industry

Abstract Steels with different mechanical and chemical properties are used together in the oil and gas industry. In this case, it has brought about the necessity of joining steels with different properties by welding. Most of the time, there are problems in welding these steels with different chemical properties. Therefore, in this study, AISI 304 stainless steel, AISI 4140 tempered steel, and S235JR structural steel with different chemical and mechanical properties used in the oil and gas industry were joined by friction welding. Then, macro and microstructure studies as well as hardness measurements, tensile tests, and torsion tests were applied to the produced samples. As a result of the micro-structure studies, it was observed that the martensitic structure was formed in the full deformation region of the joint made of AISI 304 stainless and AISI 4140 tempered steel, while it was determined that the other joints were formed of recrystallized fine grains in the full deformation region with the effect of friction. When the hardness measurement results were examined, it was determined that the hardest region was the full deformation region in all welded joints produced. As a result of the tensile tests, the highest tensile strength obtained was 622.94 N/mm2 in the joint made of AISI 304 stainless steel and AISI 4140 tempered steel. As a result of the torsion tests, the highest torsion moment was measured as 250 Nm in the sample produced from AISI 304 stainless steel and AISI 4140 tempered steel.

Friction Welding of Polycarbonate Plate and Aluminum Foam Fabricated by Precursor Foaming Process

Aluminum foam is expected to be one of the candidates for lightweight materials for structural components as it is lightweight and has excellent shock absorption and sound absorption properties. However, aluminum foam has low tensile and flexural strength due to its thin cell walls. Therefore, aluminum foam is used by combining with dense materials. In particular, with the recent trend toward multi-materials, research on the combination with lightweight resins is expected. In this study, we attempted to join aluminum foam fabricated by the precursor method to a thermoplastic resin polycarbonate (PCTA) plate by friction welding. It was found that the aluminum foam and PCTA plate can be joined in about 1 min by friction welding, by rotating the aluminum foam at 2000 rpm and pressing 1 mm into the PCTA plate. In addition, in the friction welding of aluminum foam and PCTA plate, it was found that the pores of the aluminum foam were maintained without being collapsed. The anchoring effect is presumably caused by the penetration of PCTA softened by the frictional heat generated by the friction welding into the pores. Furthermore, tensile tests of the joined samples showed that fracture occurred either at the joining interface or at the base material of the aluminum foam, and that the joining strength was equivalent to the tensile strength of the aluminum foam itself.

Plastik Birleştirme Yöntemleri: Ultrasonik ve Vibrasyon Kaynağı

Plastic welding is a common method for manufacturing parts that can’t be molded and has a complex geometry such as the part that has undercuts. The process is suitable for mass production, cheap and meets automotive requirements. The process helps the zero-emission target of the automotive industry, due to the biggest obstacle of the plastic use in this sector was the moldability of the complex geometries. Most of the engine parts such as thermostat, water pump etc. can’t be molded as one piece. These engine components are manufactured by helping the plastic welding and decrease the weight of the automobile, therefore, improving fuel efficiency. Plastic welding technology has become more important especially in electrical vehicles, because metal to plastic replacement has a significant role in decreasing the weight of the vehicle. Selecting the welding method according to the polymer properties and the geometry of parts are the most important factors for the application area. All of the welding methods are basically based on the remelting of the welding surfaces of the parts and the consolidation of them under the pressure. In this paper, the vibration welding and the ultrasonic welding methods have been inspected. The most effective parameters of both processes have been discussed and shown.

Dissimilar linear friction welding of Ni-based superalloys

Linear friction welding is a solid-state, near-net shape manufacturing method for metallic alloys which is characterised by complex deformation and metallurgical actions at the weld interface. However, a lack of understanding of the welding parameter interaction and subsequent welding mechanisms is hindering the joint integrity enhancement of dissimilar linear friction welding. In this study, we investigated the influence of various process parameters on macro/micro-formation, microstructural evolution, and properties to establish optimal welding conditions for the sound linear-friction-welded joint integrity of dissimilar superalloys, IN718, and the powder metallurgy FGH96. Increased oscillation frequency or decreased applied pressure promoted continuous dynamic recrystallisation and grain refinement, although discontinuous dynamic recrystallisation remained dominant. Enhanced dissolution of the strengthening phases (γ′ phase on the FGH96 side and δ phase on the IN718 side) was observed from the thermomechanically affected zone to the interface. The subsequent correlation between the microstructure and mechanical properties indicated that solid–solution strengthening was the dominant mechanism for enhancing interfacial bonding, which was promoted by mutual material deformation on both sides. Accordingly, to achieve synergistic plastic deformation in dissimilar linear friction welding, an optimisation strategy of welding parameter combination was proposed and validated by investigating hot compressive dissimilar Ni-based superalloys. The results of simulations of sub-size workpieces showed that using linear friction welding to manufacture bimetallic bladed disks, from conception to completion, was feasible. The paper offers an integrated solution for the full-scale manufacturing of an IN718/FGH96 blisk using linear friction welding based on microstructure–property interactions and relevant simulations, which can ideally serve as the basis for future bimetallic bladed disk manufacturing.

Structure–Property Correlation between Friction-Welded Work and Hardened Al-4.9Mg Alloy Joints

Friction welding of aluminum alloys holds immense potential for replacing riveted joints in the structural sections of the aeronautical and automotive sectors. This research aims to investigate the effects on the microstructural and mechanical properties when AA5083 H116 joints are subjected to rotary friction welding. To evaluate the quality of the welds, optical and scanning electron microanalysis techniques were utilized, revealing the formation of sound welds without porosity. The microstructural examination revealed distinct weld zones within the weldment, including the dynamically recrystallized zone (DRZ), thermo-mechanically affected zone (TMAZ), heat-affected zone (HAZ), and base metal (BM). During the friction-welding process, grain refinement occurred, leading to the development of fine equiaxed grains in the DRZ/weld zone. Tensile testing revealed that the weldment exhibited higher strength (YS: 301 ± 6 MPa; UTS: 425 ± 7 MPa) in the BM region compared to the base metal (YS: 207 ± 5 MPa; UTS: 385 ± 9 MPa). However, the weldment demonstrated slightly lower elongation (%El: 13 ± 2) compared to the base metal (%El: 15 ± 3). The decrease in ductility observed in the weldment can be attributed to the presence of distinct weld zones within the welded sample. Also, the tensile graph of the BM showed serrations throughout the curve, which is a characteristic phenomenon known as the Portevin–Le Chatelier effect (serrated yielding) in Al-Mg alloys. This effect occurs due to the influence of dynamic strain aging on the material’s macroscopic plastic deformation. Fractography analysis showcased a wide range of dimple sizes, indicating a ductile fracture mode in the weldment. These findings contribute to understanding the microstructural and mechanical behavior of AA5083 H116 joints subjected to rotary friction welding.

Experimental investigations and effect of parameters on friction welded AISI 304 and Invar alloys

ABSTRACT It is challenging to achieve sound weld quality between dissimilar materials such as AISI 304 and Invar alloys with the help of the fusion welding process due to various weld defects like slag inclusion and misalignment. In current work, Invar alloys and AISI 304 material is welded with 12 mm diameter and 70 mm length on a commercial friction welding machine. Taguchi L9 orthogonal design is utilised for experiments, and an optimised parameter combination is identified. Machining parameters such as friction rotation RPM − 1100,1300,1500 rpm, frictional pressure 33,43,53 MPa, and burn-off length 4,5,6 mm are selected for the experiments. Forge pressure is not applied in experimental tests, and the tensile strength of the weld joint is evaluated for comparison. The findings revealed that the lower friction pressure up to 43 MPa resulted in higher tensile strength up to 517 MPa and refined grains in the microstructure. The higher friction pressure resulted in lower tensile strength due to non-homogeneous temperature distribution at the weld interface. The burn-off length shows significant effects on tensile strength results beyond 5 mm. The findings demonstratedthat the process could join dissimilar materials with enhanced mechanical properties.

Enhancement of microstructure, micro-texture, and mechanical properties of Al6061 friction stir welds using the developed static shoulder welding tool

Dissolution of strengthening precipitates and grain coarsening are the key factors that dictate the mechanical properties of heat-treatable aluminium alloys. In this study, a feasible method of static shoulder friction stir welding (SSFSW) is used to reduce these adverse effects. A novel static shoulder friction welding tool is developed here in this study by incorporating rotating and non-rotating shoulders in a single tool. The effectiveness of the tool was evaluated by welding Al6061 plates under various conditions, such as conventional friction stir welding (CFSW), underwater friction stir welding (UWFSW), and SSFSW. The evolution of crystallographic texture and microstructural changes during the process is studied using electron back scattered diffraction and transmission electron microscopy. The results showed that SSFSW reduced grain size by 37% compared to UWFSW at the centre of the stir zone and increased the yield strength by 22.8% compared to CFSW. In addition, SSFSW showed a strong presence of γ-fibre, indicating improved formability and a 7.2% improvement in joint efficiency in terms of ultimate tensile strength due to a higher fraction of precipitates and higher dislocation density.

Grain size and temperature evolutions during linear friction welding of Ni-base superalloy Waspaloy: Simulations and experimental validations

This research study was aimed at investigating the influence of linear friction welding parameters on grain size alteration and temperature distribution of Ni-base superalloy Waspaloy. A 3D finite element model was developed to predict average grain size and peak temperature as responses. The linear friction welding parameters consisted of oscillation amplitude, oscillation frequency, and applied pressure. Initially, the evolution of the average grain size as a function of the most influential process parameters was subsequently modeled based on the Johnson-Mehl-Avrami-Kolmogorov recrystallization model and were then validated with experimental results. Then, D-optimal design of experiments and analysis of variance were conducted to determine the most influential process parameters that affect the average grain size and peak temperature of the welded joint. Thereafter, response surface method was employed to obtain the regression models of the responses. The analysis of variance demonstrated that the P-value of the regression models was smaller than 5% and R2, Radj2, and RPred2 were between 87% and 97%, which showed that the predictive regression models of PT and AGS can be used with a high level of confidence. The regression models were then validated by selecting two extra LFW tests in the space of the DoE. The optimum values of the welding parameters were determined to minimize the responses. The multi-criteria optimization analysis showed that both average grain size and peak temperature were more dependent on pressure than oscillation amplitude and frequency. The developed finite element and regression models can be utilized as a predictive tool for the design of joining industrial components, which minimize expensive and time-consuming experimental tests and measurements.

A New Method of Predicting the Parameters of the Rotational Friction Welding Process Based on the Determination of the Frictional Heat Transfer in Ti Grade 2/AA 5005 Joints.

The article presents an original approach to determining the basic parameters of rotational friction welding (RFW) based on the analysis of friction heat transfer at the faying surfaces. Dissimilar Ti Grade 2/AA 5005 joints were used to demonstrate the method. The work established that for the analyzed joint, the optimum temperature at the faying surface that allow for a good quality weld to be obtained should be ~505 °C. On this basis, a map of optimal parameters was developed to achieve this temperature. This approach could potentially allow for more precise control of the welding process, leading to better joint quality and performance. The paper includes both a description of the technological process of friction welding and an attempt to explain the mechanism of the phenomena occurring in the welding area. The numerical calculations presented in the article were carried out using the ADINA System v. 9.8.2, which allows for the consideration of heat friction in the axial symmetric thermo-mechanical model. Frictional resistance was determined by the temperature-dependent friction coefficient. The assumed thermo-mechanical model required the determination of elastic-plastic properties versus temperature for the analyzed materials. The simulations of the friction welding were carried out for the different welding parameters and time. The different variants of friction welding were modelled.

Elucidation of interface joining mechanism of aluminum alloy/dual-phase steel friction stir riveting (FSR) joint

The mixed use of aluminum (Al) alloy and high strength steel (HSS) is an effective way to reduce the weight of vehicles, which meanwhile brings great challenges to the traditional spot joining technologies. Three-stage friction stir riveting (FSR) process using a precisely designed semi-hollow rivet was developed for Al-steel joining. By coordination control the rotation and feed movement of the rivet, a “tube-sheet” annular solid-phase welding zone is formed between the semi-hollow rivet and the lower steel sheet, realizing the reliable joining of Al-steel dissimilar sheets combination. The rivet structure was designed to accommodate the trapped Al alloy in the rivet cavity during the friction welding stage, obtaining an inclusion-free friction welding interface which was not only mechanically mixed but also fully interatomic binding. The optimal FSR joint is composed of ferrite softening zone (FSZ), carbide precipitation zone (CPZ), ultrafine martensite zone (UMZ), and fine dual-phase zone (FDPZ). Moreover, due to the circumferential flow of materials during friction welding stage, the dynamic recrystallization (DRX) microstructures of the rivet and steel sheet both have shear texture consistent with {112}<111> and {110}<001> cube texture, which brings the uniformity of microstructure and performance. With the combined contribution of inclusion-free joining interface and the microstructure with uniform cube texture, the optimal FSR joints have the maximum average tensile-sheer strength of 281.1 MPa (90.7%·σ6061-T6) and peak load of 5.29 kN, presenting pull-out fracture mode with good fracture energy absorption.

CRYSTALLOGRAPHIC CHARACTERISTICS OF PHASE TRANSFORMATIONS IN THE FIELD OF MEDIUM-CARBON STEELS JOINT OBTAINED BY ROTARY FRICTION WELDING

Orientation (EBSD) and transmission electron microscopy have been used to study the structure and orientation relationships of α' and γ-phases in medium-carbon steels during rotational friction welding. It is shown that, as a result of phase recrystallization, martensite with interlayers of the γ phase is formed in the structure of the welded joint. The formation of secondary (reverted) austenite was established by the form of the spectrum of angular deviations of interfacial boundaries. It is shown that, in this case, an orientation relation close to the Bein one is realized between the crystals of the α and γ phases.

Crystallographic Characteristics of Phase Transformations in the Field of Medium-Carbon Steels of a Joint Obtained by Rotational Friction Welding

Crystallographic Characteristics of Phase Transformations in the Field of Medium-Carbon Steels of a Joint Obtained by Rotational Friction Welding

Optimization of parameters in rotary friction welding process of dissimilar austenitic and ferritic stainless steel using finite element analysis

Solid state joining techniques are increasingly used in joining different types of materials, in this work TP347HFG austenitic stainless steel will be welded with HiPerFer ferritic stainless-steel alloy due to their similarity in their properties to some extent after making heat treatment to ferritic alloy in addition to difference in their cost which save for economic reasons. In this work, a three-dimensional finite element model was developed. The thermal analysis and profiles between process parameters were predicted by using an ANSYS software tool. Design of experiments by Anova was used to examinate the simulation results and to evaluate contribution ratio of each parameter on responses, while grey relational analysis was used to specify the optimum trial. It was observed that trial 11 give best results (A4B2C1D1) which got higher grey relational grade. It was concluded that the friction pressure and friction time have more impact on interface temperature, whereas forging pressure and friction time affect the equivalent Von-Mises stress directly. The speed and forging pressure have a more influence on total deformation. It was also concluded that the temperature was fade out by diverging toward the end of specimen and the amount of decrease in temperature is less in ferritic side. The amount of flash extruded from both steels are approximately similar due to similarity in properties as heat treatment of ferritic alloy had been achieved. The investigation results show that trial 8 achieved highest Von-Mises stress (300 MPa) while trial 7 induced lower stress (255 MPa), maximum deformation was found equivalent to 0.012 mm with trial 16 whereas, it was found (0.008 mm) with trial 11 which were both less than the allowable deformation in end application. Tensile strength of weld joint was found equivalent to 80% of softer base metal. The hardness of optimum trial was equivalent to 156 HB.

Research of the stress-strain state of the loaded assembly for friction welded device

This article presents the results of the study of methods for friction welding of dissimilar materials and the calculations to determine the structural strength of the most loaded part of a special friction welding device were made. The analysis showed that the friction welding method has wide technological capabilities and it is used in various industries. The designs of existing devices and machines for friction welding were also investigated. It was revealed that the method of friction welding in the conditions of machine-building plants of the Republic of Kazakhstan (RK) has not found application due to the little knowledge and high cost of technological equipment. The authors have developed a special device for friction welding of dissimilar materials. To optimize the parameters of the parts, in particular the bracket part, the stress-strain state calculations were performed using the ANSYS software package and the strength calculation by determining the acting external critical loads. The results of the calculation showed the applicability of the developed design of the bracket part.

Analysis of Microstructure and Mechanical Properties of AZ31B Thick Plate Magnesium Alloy Stir Friction Welded Joints

Welding of 10 mm thick AZ31B magnesium alloy by stir friction welding technique. The effects of process parameters on the microstructure, tensile strength and impact resistance of the joints were analyzed. The results showed that the joints were formed with good quality and no obvious defects, and the joints were fine-grained and accompanied by grain dislocations. The grain dislocation in the hot machine influence zone is more obvious there is a dense grain dislocation zone, and the distribution is not uniform. When the spindle speed is 800 and 1000 rpm, respectively, the best impact resistance of the welded joint impact work is 8.02 J, which is about 94.2% of the impact resistance of AZ31B magnesium alloy base material. When the spindle speed is 1000r/min and the welding speed is 150 mm/min, the tensile strength of the welded joint is the largest, reaching 85.8% of the base material and the post-break elongation is 1.9 times that of the base material. Thick plate magnesium alloy plate welded joints overall performance is not uniform, welded plate bottom mechanical properties of the worst, weld core area doped magnesium alloy oxide, joint tensile fracture crack source from the bottom of the plate to the weld surface expansion.

Lap Joint on St.37 Steel Plate with Friction Welding Clamping Method

Friction stir (FW) welding is a relatively fresh method that was created and has been continually refined and adapted to industrial applications due to its benefits. This approach for solid-state joining entails connecting the components at a temperature below their melting point and then heating them up. Clamp joint applications are widely used using external heating and hitting with high strength, but the clamped joints with the FW method are rarely done. The research studied the characteristic of clamped joints at various plate thicknesses using the FW method. In this study, 30 specimens were used in the form of a St.37 low carbon steel plate with a size of 50 mm x 100 mm and a thickness of 3 mm, 5 mm, and 9 mm, and several holes were made with a diameter of 5 mm. The plate was connected by 2 clamps, and 4 clamps then the FW method was conducted in a milling machine. The results indicate that the plates were connected well. The highest hardness value was 256.4 VHN on the FW of 9 mm plate. The microstructure is dominated by ferrite and a little pearlite phase. The largest shear force is 66.54 kN obtained at 4 clamps with a plate thickness of 9 mm, and the lowest is 13.46 kN, obtained at 2 clamps with a plate thickness of 3 mm.