Friction Welding Research Articles

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

Research Progress of Aluminum Alloy Welding/Plastic Deformation Composite Forming Technology in Achieving High-Strength Joints.

Fusion welding causes joint deterioration when joining aluminum alloys, which limits the use of aluminum alloy components in high-end equipment. This paper focuses on an overview of how to achieve high-strength aluminum alloy welded joints using welding/plastic deformation composite forming technology. The current technology is summarized into two categories: plastic deformation welding and plastic deformation strengthening. Plastic deformation welding includes friction stir welding, friction welding, diffusion welding, superplastic solid-state welding, explosive welding, and electromagnetic pulse welding. Plastic deformation strengthening refers to the application of plastic deformation to the weld seam or heat-affected zone, or even the whole joint, after welding or during welding, including physical surface modification and large-scale plastic deformation technology. Important processing parameters of plastic deformation welding and their effects on weld quality are discussed, and the microstructure is described. The effect of plastic deformation strengthening technology on the microstructure and performance evolution, including the hardness, tensile strength, fatigue property, residual stress, and hot cracking of aluminum alloy welded joints, and its evolution mechanism are systematically analyzed. Finally, this paper discusses the future development of plastic deformation strengthening technology and anticipates growing interest in this research area.

A Study of Annealing Effects on the Joints of a Rotary Friction Welds of AISI 1030 Steel

This study is concerned with the post-heat treatment of rotational friction welds. AISI 1030 carbon steel parts are welded by rotational friction welding (RFW). The welding process parameters include friction pressure (P1), friction time (T1); Forging pressure (P2), forging time (T2). During the friction phase, the rotational speed is 1450 rpm; after that, the welding parts is stopped immediately and pressed together. The weld samples will be annealed at 650 °C for 4 hours. The change in the properties of the material of a RFW weld joint such as hardness, tensile strength, bending strength as well as grain size when undergone a heat treatment process was investigated. The obtained results show that the annealing process strongly changes the mechanical properties through altering the microstructure of the weld. Particularly, the weld hardness and tensile strength decrease significantly while the bending strength and elongation increase as a result of the increase in grain size and uniformity of the phase distribution. The annealed weld has a hardness reduction of nearly 20% and a tensile strength reduction of about 24% compared to the original weld. The elongation in the tensile test increases from 1.1% for weld specimens to 2.54% for post-heat-treated welds. In the bending test, the maximum load before the appearance of cracks on the specimen increased by about 42% when comparing the post-heat and original weld specimens.

Studying the Effects of Annealing on the Mechanical Properties and Microstructure of Ultrasonic Vibration Welds

The impact of heat treatment on the mechanical characteristics and microstructure of an ultrasonic vibration metal inert gas (MIG) weld is examined in this study. The findings show that the heat treatment method has a significant influence on the mechanical characteristics and structure of the welding specimens. The annealing will increase the grains’ size, thereby reducing the hardness and increasing the ductility of the joint. Due to the impact of ultrasonic during welding, the microstructure in fusion zone of both annealed and non-annealed specimens showed small and fine grain structure (with the grain size being measured at less than 40µm). The result also demonstrates that during annealing, the carbon tended to diffuse from the area of high density to the region of low density, resulting in a reduction in hardness compared to the initial sample. Also, it was discovered that elements that lower weld strength (such as the irregularity of the grain structure and the dendritic structure produced by metal crystallization) significantly decreased.

Ultra-high pulse pressure induced particle surface thermal field assisted preparation of W–Al composite

Particle surface thermal field (PSTF) is an inhomogeneous thermal field that concentrates the heat effect on the surface of particles, and it can be utilized to fabricate composite materials with large differences in physical properties. However, it is difficult to form PSTF with large temperature gradients to meet the preparation requirement of materials with extreme differences in physical properties. In our work, a PSTF is proposed and realized by an ultra-high pulse pressure (UHPP) to prepare W–Al composite, the PSTF has a heating effect on the powder interface with a low-temperature interior of the powders. The combination of ex-situ microstructural observation and in-situ molecular dynamic simulation microstructural snapshot is used to demonstrate the densification mechanism. The PSTF is characterized as the temperature higher than 1200 °C on the W–Al powders interface but lower than 200 °C interior of the powders. The densification mechanisms are explained as interfacial jet penetration, interfacial friction welding and interfacial melting. In addition, interfacial temperature distribution creating gradient pressure on the W–Al interface illustrated the generation of gradient Al grains on the W surface, thus creating a high mechanical micro-hardness of 249.8 Hv and compressive strength of 473.2 MPa for the W–Al composite.

Investigation of joints from corrosion-resistant steels obtained by energy-saving rotary friction welding technology

In this article the possibility of application of rotary friction welding for joining parts from stainless steels is evaluated on the example of 10Cr17Ni13Mo2Ti steel. Application of rotary friction welding allows to refuse post-weld heat treatment, which is labor-intensive, energy-consuming and environmentally harmful operation. For this purpose, cylindrical samples of 20 mm in diameter were made from the above steel using friction welding without subsequent heat treatment. The microstructure, microhardness measurement, tensile and impact bending tests were carried out. The microstructure study showed that the weld width across the entire cross-section does not exceed 12 μm. It has an irregular wavy shape with a fine-grained structure. Tensile tests showed that the average value of yield strength of samples with welded joint is 1.6% higher than the same value of samples from the base metal, but the average value of time resistance is lower by 5.6%. Impact bending test results showed that the average impact toughness of welded samples is almost the same as that of base metal samples. According to the results of studies concluded that the weldability of steel 10Cr17Ni13Mo2Ti using friction welding is good, welded joints are obtained high quality.

Evaluation of the effect of welding technology on the operational characteristics of joints

The purpose of the study presented in the article is a comparative analysis of operational characteristics, namely strength and tightness, of welded samples of corrosion-resistant steel on the example of 10Cr17Ni13Mo2Ti steel. These samples were obtained by different technologies: the more environmentally friendly technology of rotary friction welding without heat treatment and the currently used technology of arc welding and post-weld heat treatment. Special tooling was developed for the tightness tests and the tests were carried out on a hydraulic test bench. For the strength tests, the tooling was also developed and the tests were performed on a tensile testing machine. Tightness testing of the samples showed that both types of samples could withstand a test pressure of 12 MPa, including 0 to 2 mm tube wall thinning (0 to 80% of the original thickness), and 35 MPa, including 0 to 1 mm tube wall thinning (0 to 40% of the original thickness). The strength tests showed that the samples obtained by friction welding, under the conditions of tests on pulling the tube from the equivalent sleeve, withstand the maximum load to failure, exceeding by 14.9% the corresponding index of the samples obtained by arc welding.

Mechanical and Microstructural Characteristics of Rotary Friction Welded SS316L and Pure Copper with Added MWCNT Nano Additives

This study explores the novel design of geometric rubbing profiles on rotary friction welding for enhanced mechanical clamping in joining dissimilar alloys such as copper and stainless steel 316L. The clamping behavior of rubbing profiles could hold the yielding of the weld joint to a maximum level. An innovative approach to effective mixing of the weldment zone could be achieved through the definition of rubbing profiles. The effective dispersion of dissimilar metallic phases could be governed by the geometrical profile in achieving the intermetallic SS-Cu phase. Variations were made in welding parameters like tool rotational speed, upset pressure, upset time, friction pressure, and friction time to find the appropriate process for the four different rubbing profiles, namely helical fluke, plus, cylindrical, and flat to achieve a reduction in micro and macro-structural defects with strong weld nugget. Results show that helical fluke rubbing profiles were seen to have explicit values like ultimate tensile strength of 217 MPa (upset pressure), elongation of 9.8 % (upset pressure), and average hardness of 125 HV (friction pressure) at the weld nugget. Microstructural characteristics prove that the formation of IMCs through grain size reduction such as cementite increases the Vickers hardness of the weldment.

The Effect of Variation of Bar Surface Chamfer Angle on Rotary Friction Welding Connections

This study aims to determine the effect of chamfer angle variations on flash, welding time, interface and hardness values at welded joints of similar materials. The method was used, with parameters of the rotational speed of 4.335 rpm, friction pressure of 0.5 MPa, forging pressure of 0.7 MPa, forging time of 10 seconds and chamfer angle variations of 0°, 15°, 30°, 45°. Then, the specimen result was tested using the projector profile, Non-Destructive Test (NDT), macro-observation, and Vicker test. The result showed that the greater the chamfer angle variation on the given bar surface, the smaller the size of the resulting flash. The smallest flash dimension was produced at a chamfer angle variation of 45°, with an average flash height of 1.03 mm, successfully reducing the flash height by 62% from variations without chamfer angles. Moreover, an average flash width of 0.26 mm reduced the flash width by 77% of the variation without a chamfer angle. Therefore, the greater the variation of the chamfer angle, the smaller the flash size and the more significant the variation of the chamfer angle, the longer the welding time. In the interface area, chamfer angle variations do not affect cracks and voids. The chamfer angle affects the average hardness value, where the more significant the chamfer angle, the more the hardness value is increased.

Structuring step dependent characteristics in joining using pin-like structures in the vibration welding process

Abstract With this study, correlations in the structuring step of pin-like joining were derived. Increased friction energy due to higher amplitude or force leads to a reduction in structuring time. Changes in thermo-mechanical properties for humid specimens result in increased process times. The theoretical geometry of the pin-like structures is well reproduced in the lower pin area, regardless of the process control. In the upper pin area, increased force and amplitude results in increased defects and air inclusions as a result of an accelerate and more inhomogeneous pin formation. Humidity does not affect the general pin geometry, but should be avoided due to increased air inclusions that can weaken the structure. For the multi-material joints, high bond strengths of up to 30 % of the base material (max. 50 % possible with the geometry used) can be achieved. Therefore, a minimum undercut is required. Once this is reached, the pin defects and the corresponding pin-foot ratio are decisive for the resulting bond quality.

Characterization of the Polyetheretherketone Weldment Fabricated via Rotary Friction Welding.

Polyether ether ketone (PEEK) is frequently employed in biomedical engineering due to its biocompatibility. Traditionally, PEEK manufacturing methods involve injection molding, compression molding, additive manufacturing, or incremental sheet forming. Few studies have focused on rotational friction welding (RFW) with PEEK plastics. Based on years of RFW practical experience, the mechanical properties of the weldment are related to the burn-off length. However, few studies have focused on this issue. Therefore, the main objective of this study is to assess the effects of burn-off length on the mechanical properties of the welded parts using PEEK polymer rods. The welding pressure can be determined by the rotational speed according to the proposed prediction equation. The burn-off length of 1.6 mm seems to be an optimal burn-off length for RFW. For the rotational speed of 1000 rpm, the average bending strength of the welded parts was increased from 108 MPa to 160 Mpa, when the burn-off length was increased from 1 mm to 1.6 mm and the cycle time of RFW was reduced from 80 s to 76 s. A saving in the cycle time of RFW of about 5% can be obtained. The bending strength of the welded part using laser welding is lower than that using RFW, because only the peripheral material of the PEEK cylinder was melted by the laser.

Life cycle assessment study on glove box assembly of Indian passenger vehicles

The automotive sector is one of the major greenhouse gas (GHG) emissions contributors and it accounts for around 17% of the total GHG emissions across the world. Most of these passenger vehicles in India are sub-4-meter vehicles hence, it becomes important to analyze the environmental impacts of these vehicles. Even though emissions are a major contributor to GHG emissions, the interiors are also one of the major contributors to GHG emissions during the life cycle of a passenger vehicle. The Glove box contributes significantly to the interior consideration. The present study focuses on analyzing the environmental impacts of a glove box with multiple option scenarios using the life cycle assessment (LCA) methodology in accordance with ISO 14040: 2006. A cradle-to-grave approach was chosen to perform LCA on various design alternatives made of different raw materials (PPTD15, PPTD20, and PPTD25), manufacturing process (hotplate welding, vibration welding, and fastening), latching concept (side and central), and storage concept (rotating bin, fixed bin part of substrate, and fixed bin not part of substrate) of the glove box. The life cycle impacts are analyzed, and it was observed that the fixed bin not part of the substrate has the least environmental impacts with PPTD15 raw material, central latching mechanism, and fastening manufacturing process combination. In addition, this study observed that the use phase is the major contributor to overall impacts, which accounts for around 72–75% of total impacts. It was recommended to use recycled and renewable energy sources during raw material manufacturing and renewable energy as a source of fuel/electricity during the use phase of the glove box to reduce the environmental burden.

The improvement of the threaded-based mechanical splice by modifying the threaded system: Study of techniques cold rolling and rotating friction welding

In this study, by modifying the method of making a threaded splice and combining it with rotary friction welding, two types of patches are introduced. The aim is to modify the failure area of the coupler with a threaded bar and use it in the plastic hinge areas of ductile members in seismic areas. The splice area in the suggested method is oversized. To enlarge the splice area, two techniques-cold rolling and rotating friction welding are used. In total, 96 samples (including three repeated samples of each type) were tested. Threaded couplers (TC), oversize-threaded couplers (OTC), rotary friction welding splices with threaded couplers (RFWTC), and non-spliced reference specimens underwent uniaxial tensile and cyclic testing with and without concrete (NS). The sensitivity to bar diameter, as well as bar strength, ductility, energy absorption, and failure mode performance, were evaluated. In terms of strength, ductility, energy absorption, and failure mode, the RFWTC and OTC performed the best and are suited for usage in high seismic zones. Additionally, the TC is appropriate for use in low-to-medium seismic zones. Also, the predicted model is sufficient to estimate the ultimate tensile strength of the threaded couplers.

Jointing Achievement and Performance Evaluation of Bogie Crossmember Ring Joint Welded via Inertia Friction Welding.

As a major load-bearing component of trains, the weld quality of the bogie beam is critical to the safety of railway operations. This study specifically investigates the inertia friction welding process of S355 bogie crosshead tubes, with the aim of improving the weld quality and achieving one-time formation of the crosshead tube and tube seat. The microstructural features and mechanical properties of S355 inertia-welded joints were also compared with the base metal. Research indicates that inertia friction welds have no visible defects, and that the microstructure of the welding seam (WS) consists of granular bainite, acicular ferrite and little pearlite. The thermo-mechanically affected zone (TMAZ) consists of granular bainite bands and ferrite + pearlite bands. The hot work strengthening mechanism of inertia friction welding results in a higher level of hardness for both WS and TMAZ. The tensile property of the welded joints can be compared to the base metal. The yield strength, tensile strength and elongation of the welded joints, respectively, reach 87.5%, 100% and 79.5% of S355. However, the impact toughness of the welds at room temperature is lower than that of the base material, particularly in the TMAZ zone. Conversely, in an environment with a temperature of -40 °C, WS's impact toughness surpasses that of the parent material.

Model development for numerical analysis of the bonding strength for friction welded lightweight structures

The rotary friction welding (RFW) is a robust, precise, productive and economical joining process that is used in many areas of mechanical engineering to produce lightweight structures consisting of combinations of ferrous and non-ferrous materials, for instance aluminium alloy and steel. Crucial for the design of such lightweight structures is the knowledge about the bonding strength. The bonding strength is the result of the bond formation depending on the present transient kinematic, kinetic and thermal states during the welding process being directly determined by the welding process parameters. Despite several years of empirical research, no reliable numerical modelling approach exists for the RFW process to analyse the bonding strength based on these transient state variables. For this reason, an improvement of the bond formation and therefore an increase in the bonding strength can only be tested experimentally. The main motivation of this paper is to develop an appropriate modelling approach for the estimation of the bonding strength for friction welded lightweight structures manufactured of an aluminium alloy and a structural steel. Therefore, a couple of aluminium alloy and steel welding experiments with different process parameters were performed and subsequently analysed concerning to the resulting bonding strength. Moreover, all the welding experiments were simulated in regard to the corresponding welding process in order to determine the present kinematic, kinetic and thermal state variables, like the strain rate, the stress and the temperature. Thus, a model for the characterization of the bond formation can be developed, which allows a correlation between the bond formation and the resulting bond strength based on the chosen welding process parameters. Finally, the model will be examined and discussed in terms of its plausibility and applicability.

Rotary Friction Welding of Dissimilar Polymer Rods Containing Metal Powder.

Three-dimensional printing is widely used for manufacturing a variety of functional components. However, the 3D printing machine substantially limits the size of the functional components. Rotary friction welding (RFW) is a possible solution to this problem. In addition, there is a notable scarcity of research directed toward the domain knowledge of RFW involving dissimilar polymer rods containing metal powder. In this study, two welding specimens fabricated by polylactic acid (PLA)-containing copper powder and PLA-containing aluminum powder were joined using a turning machine. After RFW, a bending test and a Shore A surface hardness test were performed to investigate the weld quality. It was found that the bending strength of the welded parts fabricated by RFW of PLA and PLA-containing Al powder rods can be enhanced by about 57.5% when the welded part is placed at 45 °C. Surface hardness test results showed that the surface hardness of the weld interface is better than that of the 3D printed parts, and the average surface hardness of the weld interface from RFW of PLA and PLA is the highest. The surface hardness of the weld joint is about 3% higher than that of the base material. The surface hardness of the heat-affected zone is about 3% lower than that of the base material. The average peak temperature of the welded joint is the highest in the RFW of PLA-containing Al powder and PLA-containing Al powder rods. The average peak temperature of the weld joint can be as high as 160 °C. The average peak temperature of the welded joint is the highest in the RFW of PLA-containing Cu powder and PLA-containing Cu powder rods. The average peak temperature of the welded joint can be as high as 144 °C. A technical database was built for the selection of ambient temperatures used for the RFW of dissimilar polymer rods containing metal powder and three base materials.

Critical Review on Magnetically Impelled Arc Butt Welding: Challenges, Perspectives and Industrial Applications.

Magnetically Impelled Arc Butt (MIAB) welding is a cutting-edge joining method that replaces the conventional welding procedures such as resistance, friction, flash and butt welding. It is a solid-state process that uses a rotating arc to heat up the butt ends of tubes, being followed by a forging process that completes the joining of the workpieces The magnetic flux density and the current interact to develop the Lorentz force that impels the arc along the faying surfaces. This process is found to produce high tensile strength and defect-free welds in ferrous materials and for this reason, it is predominantly employed in automobile applications for joining metallic tubes. Also, this joining procedure can be applied in the fabrication of boilers, heat exchangers, furnace piping in petrochemical industry and other safety-critical high-pressure machinery parts. The MIAB method has several advantages such as a shorter welding cycle, lower input energy requirement and lower loss of material. Compared to other solid-state welding processes, the MIAB welding has an important advantage in terms of cost-efficient welds with better control and reliability. Moreover, there are researchers who have investigated the joining of non-ferrous dissimilar materials using this welding procedure. The studies have been focused on process parametric analysis that involves optimizing and forecasting the magnetic field and thermal profile distribution. This review article provides competitive insights into various design features, computational methods, tests and material characterization, technical issues and workarounds, as well as automation aspects related to the MIAB-welding process. This work will prove to be a quick reference for researchers, useful to identify the research gaps and conflicting ideas that can be further explored for advancements in joining the similar and dissimilar materials.

Microstructure evolution and tensile strength of Al/Cu inertia friction welded joint

To save production costs and reduce the weight of structures, it is one of the common ways to replace copper (Cu) with aluminum (Al) in some industries such as the refrigeration industry. The high-quality welding of Al to Cu determines the application of the Al/Cu hybrid structure. The inertia friction welding process was used to weld Al pipe to Cu pipe and the Taguchi experiment method was used to study the effects of inertia friction welding parameters on the mechanical properties of the welded joints, and the results show that the initial speed has the greatest influence on the tensile strength of welded joints. Meanwhile, the analyses of the microstructures of the joint show that Al–Cu IMCs formed at the friction interface to realize the metallurgical bonding of the welded joints. The formation sequence of Al–Cu IMCs in the friction welding process is Al2Cu, Al4Cu9, and AlCu. Whereas the type and thickness of IMCs are closely related to the tensile strength of the joints. When the welded joint forms Al2Cu and Al4Cu9, the interfacial misfit between the IMCs layer and base materials is minimized and the tensile strength of the joint is optimized.

Development Of Dissimilar Micro Friction Stir Welding Copper With Alumniumum Plate

Friction welding as joining method has a good joining condition. The results of FSW welding have the advantage that the surface is smoother and flatter than the results of arc welding. Friction rotary welding includes several stages, namely material welding and microstructural analysis. In this study the material welding was used copper and aluminum alloy 1100 with sizes 60mm, 50mm, 0.5mm and macro structural analysis using a digital microscope. Experiments were carried out using lap joints with dimensions of 100mm, 50mm, 0.5mm with variations in loading parameters of 30kgf, 40kgf, 50kgf and variations in shoulder diameters of 4mm, 6mm, 8mm. In the experiment, the larger the diameter of the shoulder, the greater the loading required to connect the two materials, but if the loading is too large, it can cause defects in the welding results. The welding results at the welding pressure parameter of 40kgf with a shoulder diameter of 8mm show that welding with these parameters is capable of performing welding because the areas of the welding results are evenly connected and there are no holes (hooks) in the welding results. The results of welding at a welding pressure parameter of 50kgf with a shoulder diameter of 8mm show that the results of joining the copper and aluminum are mixed evenly but damage the surface of the copper. The macro structural results show that the welding pressure affects the shoulder diameter, if the welding pressure is too large and the shoulder diameter is too small it will only damage the copper and aluminum material because it only has a thickness of 0.5 mm, and vice versa if the welding pressure is too small and the shoulder diameter is too large, the two materials cannot be connected. In this study, the best results were obtained with a shoulder diameter of 4mm and a pressure of 40kgf because there were no defects or holes in the welding results.

Thermomechanical effect on the properties of stainless steels using rotative friction welding: an experimental study on 304L and 316L grades

Thermomechanical effect on the properties of stainless steels using rotative friction welding: an experimental study on 304L and 316L grades