{"title":"Linear friction welding of T-Joints in low carbon steel: Effect of welding parameters on joint quality","authors":"","doi":"10.1016/j.jajp.2024.100267","DOIUrl":"10.1016/j.jajp.2024.100267","url":null,"abstract":"<div><div>Linear friction welding (LFW) is a well-established solid-state joining technique. However, its application in T-joint configurations remains unexplored. This study investigated the effects of welding parameters, such as oscillation direction, upset, and applied pressure after oscillation, on linear friction welded (LFWed) T-joints using low-carbon steel SM490A. The flash ejection behavior, flash profiles, microhardness, microstructure at the welding interface, and tensile properties of the joints were evaluated under various welding conditions. The results indicated that flash symmetry was lower along the oscillation direction and higher perpendicular to it. Short-side oscillation produced more homogeneous flash ejection compared to long-side oscillation. No distinct softening zones were observed in the hardness profiles of the LFWed T-joints. The microstructure at the welding interface consisted of martensite, bainite, and ferrite, indicating that the weld region reached temperatures above the <em>A<sub>1</sub></em> temperature. The martensite fraction and hardness increased with higher upset and applied pressure after oscillation. Tensile tests revealed 100 % joint efficiency across all welding conditions, with ductile fracture occurring in the base metal due to the absence of welding defects and increased hardness at the interface.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of the material properties on the clinching process and the resulting load-bearing capacity of the joint","authors":"","doi":"10.1016/j.jajp.2024.100263","DOIUrl":"10.1016/j.jajp.2024.100263","url":null,"abstract":"<div><div>This study focuses on the phenomenological change in material strength caused by a specific heat treatment and the subsequent analysis of the influence on the clinching process and the resulting joint properties. For this purpose, three series of tests were performed. In the first series of tests, the influence of heat treatment up to 340 °C on the mechanical properties of an age-hardenable AlMgSi alloy was investigated. Holding time and temperature were varied and the material strength was evaluated by tensile and hardness tests. Two strength-increasing and two strength-reducing heat treatment parameters were identified. In the second series of tests, selected heat treatment parameters were applied to a larger number of specimens and the joint strength was investigated by shear and head tensile tests. In the shear tensile test, mainly the properties of the punch-side material have an influence on the resulting joint strength. A change in strength of the die-side material can be neglected. In contrast, the properties of both sheets are important in the head tensile test. The strength of the joint will only increase if the strength of both sheets is increased. In general, a strength increasing heat treatment resulted in higher joint strength. In the third series of tests, the factor of punch displacement was considered, which was demonstrated to directly influence the formation of the clinched joint geometry.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joining by forming of bi-material collector coins with rotating elements","authors":"","doi":"10.1016/j.jajp.2024.100265","DOIUrl":"10.1016/j.jajp.2024.100265","url":null,"abstract":"<div><div>This paper presents a novel manufacturing process for producing innovative bi-material collector coins with free-rotating inner elements. The inner elements are fabricated using additive manufacturing, enabling the creation of coins with complex and intricate geometric details that would be unattainable using conventional wrought materials. The outer elements (rings) are metallic, and this study addresses the challenge of securely connecting them to the inner elements through force-closed mechanisms formed during the coin minting process. Finite element modeling, combined with experimentation on bi-material (polymer-metal and metal-metal) coins, is employed to analyze material flow, assess minting forces, and evaluate contact pressures at the force-closed joints. The analysis ensures that adequate destructive forces are required to separate the inner elements from the rings and provides insights into selecting the appropriate process parameters for simultaneous coining and joining. The successful production of the first bi-material collector coin prototypes with free-rotational inner elements validates the overall development.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancement of joint quality for laser welded dissimilar material cell-to-busbar joints using meta model-based multi-objective optimization","authors":"","doi":"10.1016/j.jajp.2024.100261","DOIUrl":"10.1016/j.jajp.2024.100261","url":null,"abstract":"<div><div>In the battery pack assembly, it is essential to ensure that the cell-to-busbar joints can be produced with high quality and with minimal impact on the individual battery cells. This study examines the influence of process parameters on the joint quality for nickel-plated copper and steel plates, laser welded in an overlap configuration. Artificial neural network-based meta models, trained on numerical results from computational fluid dynamics simulations of the laser welding process, are used to predict and evaluate the joint quality. A set of optimized process parameters is identified, in order to simultaneously maximize the interface width for the joints, and minimize the formation of undercuts and in-process temperatures. In an meta model-based multi-objective optimization approach, the non-dominated sorting genetic algorithm II (NSGA-II) is used to efficiently search for trade-off solutions and the meta models are used for objective approximation. As a result, the objective evaluation time is decreased from around 9 h, when evaluated directly from numerical simulations, to only tenths of a second. From the Pareto-optimal front of trade-off solutions, three optimal solutions are selected for validation. The selected solutions are validated through laser welding experiments and numerical simulations, resulting in joints with large interface widths and low in-process temperatures without a full penetration.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterization of physical metallurgy of quenching and partitioning steel in pulsed resistance spot welding: A simulation-aided study","authors":"","doi":"10.1016/j.jajp.2024.100264","DOIUrl":"10.1016/j.jajp.2024.100264","url":null,"abstract":"<div><div>This study mainly focuses on the microstructure evolution of QP980 steel during resistance spot welding and its influence on the mechanical performance of resistance spot welds which is a critical influencing factor on the quality of body-in-white at the service condition. It is observed that the thermomechanically engineered microstructure of QP980 steel changes to form metastable phases such as martensite in the fusion zone and the heat affected zone due to rapid cooling induced by the thermal cycle of the welding. A finite element modeling of the welding process was used to predict the weldment heat distribution, thermal history and microstructure evolution in different welding zones. The modeled thermal history of the weldments shows that the peak temperature in the four-pulse resistance spot welding is delayed because of pulsed welding conditions and holding times between the welding pulses. This heat management approach in pulsed welding prevents void formation. The modeled thermal history and rapid heating, and cooling conditions are discussed here to predict the microstructure evolution and transformation in the fusion and reheated zones. The modeled results were helpful in the prediction of the microstructure at different weld zones. Then the strategic links between the microstructure and mechanical performance of the welded alloy are discussed thoroughly. The microhardness profile of the weld is discussed from a microstructural point of view to disclose the physical metallurgy of the welds. Softening phenomena were not observed in the sub-critical heat affected zone.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142550553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Improving the joint strength of thermoplastic composites joined by press joining using laser-based surface treatment","authors":"","doi":"10.1016/j.jajp.2024.100260","DOIUrl":"10.1016/j.jajp.2024.100260","url":null,"abstract":"<div><div>Fibre-reinforced thermoplastic composites (TPC) provide an automated and cost-effective solution for their use in lightweight structures in series production. The combination of different material configurations allows the design of highly stress tolerant components. Previous studies demonstrated that the combination of TPC sheets, TPC hollow profiles and injection moulding compounds is even suitable for crash-relevant automotive parts. All three components are combined during the injection moulding process. To prevent collapse, the part must remain in a consolidated state and cannot be preheated. However, this results in poor adhesion between the hollow profile, the bulk material, and the TPC sheet. Previous studies have shown that the bonding strength between the hollow profile and the injection moulding compound can be increased by surface pre-treatment using laser structuring and plasma technology. In this work, laser structuring is employed to enhance the bonding strength between the hollow profile and the TPC sheet. Microscopy analysis is used to investigate the resulting surface morphology. Subsequently, single-lap-shear (SLS) specimens are produced by pressing the TPC sheets onto the flat part. The resulting bonding strengths are then evaluated by tensile shear tests. The study analyses the impact of various pre-treatment parameters on the bonding strength. Furthermore, it investigates the effect of sheet temperature on the bonding strength, including specimens without pre-treatment. Finally, the results of the surface treatment of hollow composite profiles are discussed.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142550552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigation of the electrical quality and long-term stability of aluminum ground stud connections in automotive applications","authors":"","doi":"10.1016/j.jajp.2024.100262","DOIUrl":"10.1016/j.jajp.2024.100262","url":null,"abstract":"<div><div>The rapid advancement in the electrification of modern vehicles has led to a continuous increase in electrical consumers for various comfort and safety functions. Ground studs serve as the electrical interface between the conductive vehicle body and the onboard network. Drawn arc stud welding is an economical and established joining process for producing ground stud joints. The circuits in the onboard network are increasingly subject to greater demands regarding current-carrying capacity and long-term stability. Reliable signal and power transmission require minimal contact resistance at the electrical connection points of the ground stud system and must withstand various operating and environmental conditions over the entire service life. In this study, a ground stud made of AlMg5, with a ZnNi-coated steel cap nut was used on a 2.0 mm thick sheet of AlMg3. The electrical connection of the ground studs was made using tinned copper cable lugs and 35 mm² cables. To analyze the electrical resistance behavior in an accelerated test, the ground studs were subjected to a superimposed load with a cyclic current profile for 1008 h under changing climatic conditions. The results show that under the chosen operational and environmental conditions, accelerated aging and intermittent resistance behavior occur. A characteristic drop in resistance during the test indicates the failure point of the electrical connection. The cause of failure can be attributed to media penetration into the electrical contact zone. A failure of the electrical connection was observed after 512 h.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of triflute pin geometry on defect formation and material flow in FSW using CEL approach","authors":"","doi":"10.1016/j.jajp.2024.100259","DOIUrl":"10.1016/j.jajp.2024.100259","url":null,"abstract":"<div><div>Complicated tool pin designs in Friction Stir Welding (FSW) need to be considered in terms of material flow and defect formation. This study investigates the effects of the triflute tool's geometrical parameters on temperature, strain, void formation, and material mixing using a numerical method. The numerical model employs a coupled Eulerian-Lagrangian (CEL) formulation and successfully predicts void formation and material mixing during friction stir welding (FSW). Four tool pin designs are considered for material flow, including one cylindrical pin and three triflute pins with flute radii of 1 mm, 1.5 mm, and 2 mm. The findings indicate that the stir zone is divided into shoulder-driven and pin-driven zones, each exhibiting distinct material flow patterns. In the shoulder-driven zone, material flow toward the advancing side is dominant, while in the pin-driven zone, it flows toward the retreating side. Flutes on the FSW pin tool increase the sweeping rate, strain, and material movement in the stir zone. However, flutes with a larger radius sweep a greater amount of material and thus require more softened material to facilitate movement. Therefore, for defect-free joint formation, a higher rotational speed of the tool will be required, which may adversely affect tool lifespan and joint mechanical properties. The effectiveness of flutes with a smaller radius of 1 mm is significantly greater than that of those with a larger radius (1.5 or 2 mm) in enhancing material flow and achieving defect-free welding.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effects of water cooling of friction stir welding of magnesium alloy stiffness joint","authors":"","doi":"10.1016/j.jajp.2024.100257","DOIUrl":"10.1016/j.jajp.2024.100257","url":null,"abstract":"<div><div>This study presents a comparative analysis of friction stir welding (FSW) and underwater friction stir welding (UFSW) of AZ31 magnesium alloy in T-configuration, emphasizing the effects on heat distribution, material properties, and mechanical performance. Simulation results revealed a more uniform heat distribution in both welding techniques, with the hottest area on the advancing side. The maximum temperatures recorded at the shoulder-workpiece contact were 404 °C for FSW and 349 °C for UFSW, a 13.6 % reduction in UFSW. Material velocity at the trailing edge was 63 mm/s for FSW and 42 mm/s for UFSW, showing a 34 % decrease due to lower heat generation in UFSW. Strain rates were 450 s⁻¹ for FSW and 420 s⁻¹ for UFSW. Grain size in the stir zone was 26 micrometers for FSW and 21 micrometers for UFSW, a 19 % reduction. Ultimate tensile strength (UTS) increased by 6 % in the skin direction and 12.8 % in the flange direction for UFSW compared to FSW. SEM analysis indicated enhanced ductility in UFSW fractures. These results demonstrate UFSW's superiority in improving thermal management, microstructural properties, and mechanical performance of welded joints.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Enhancing bending strength in continuous drive friction welding of PEEK polymer cylinders through the innovative progressively increased welding area method","authors":"","doi":"10.1016/j.jajp.2024.100255","DOIUrl":"10.1016/j.jajp.2024.100255","url":null,"abstract":"<div><div>The continuous drive friction welding (CDFW) stands out for its low energy consumption within the welding realm. Polyetheretherketone (PEEK) represents a high-performance engineering thermoplastic, falling under the polyaryletherketone family. Renowned for its outstanding mechanical, thermal, and chemical attributes, PEEK finds utility across a diverse array of industries. However, the discovery of numerous voids at the weld interface has revealed limitations in the mechanical properties of PEEK welded samples. This study introduces an innovative approach named progressively increased welding area (PIWA) method, to mitigate voids within the weld interface. In general, the Taguchi method was used to optimize the process parameters of CDFW of dissimilar PEEK round rods to reduce random efforts by the trial-and-error method. It was found that the proposed PIWA method can definitely enhance the bending strength of rotational friction welded samples due to reduction of voids inside the weld interface. The optimal process parameters for the CDFW with the PIWA method involve a rotational speed of 2500 rpm, a cone angle of 120°, a cone top width of 8 mm, and a feed rate of 0.1 mm/s. The most influential factor affecting the bending strength of the PEEK welded samples is the feed rate, followed by cone angle, rotational speed, and cone top width. Specifically, the contribution ratios for feed rate, cone angle, rotational speed, and cone top width are about 71 %, 20 %, 7 %, and 2 %, respectively. The confirmation tests showed that the bending strength of the PEEK welded samples using optimal process parameters can be increased by approximately 68 % compared with the maximum bending strength of 180 MPa using the conventional method with a cone angle of 180° The proposed PIWA method has industrial applicability and practical value because this technique can enhance the mechanical properties of PEEK welded samples under low environmental pollution and energy consumption.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}