Journal of Advanced Joining Processes最新文献

{"title":"Investigation of joint shapes for friction welding between 7075-T6 Al alloy and low carbon steel with an insert metal of pure Ti","authors":"Masaaki Kimura ,&nbsp;Yuki Tamakoshi ,&nbsp;Masahiro Kusaka ,&nbsp;Koichi Kaizu","doi":"10.1016/j.jajp.2026.100373","DOIUrl":"10.1016/j.jajp.2026.100373","url":null,"abstract":"<div><div>Direct friction welding between type 7075-T6 aluminum alloy (AA7075) and low carbon steel (LCS) is particularly difficult, as cracking often form in the AA7075 flash and propagate to the weld interface during the welding process. This study investigated the simultaneous friction welding of AA7075 and LCS using commercially pure titanium (CP-Ti) as an insert metal in a single-step process, with the aim of achieving a joint free of cracks into the AA7075 flash. The joint free of cracks into the AA7075 flash was not obtained by varying of only the shape of the CP-Ti insert metal. However, flash cracking could be prevented when the weld diameter of the AA7075 side was larger than that diameter of the CP-Ti insert metal, and used with a suitable shape of CP-Ti insert metal having the groove to the AA7075 side. Furthermore, the joint having high tensile strength exceeding the yield strength of the LCS base metal was achieved; specifically, a forge pressure of 400 MPa resulted in approximately 83% of the tensile strength of the LCS base metal. Despite these improvements, the good joint such as fracture occurring within the LCS base metal could not be realized, since the adjacent region of the LCS side is not much deformed even if the joint is made with high forge pressure. Hence, further optimization of the CP-Ti insert metal shape is essential to promote greater deformation of the LCS side and enhance overall joint characteristics.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100373"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical investigation of an orbital forming process to join dissimilar materials with local material accumulation","authors":"A. Harms,&nbsp;D. Römisch,&nbsp;D. Reisacher,&nbsp;M. Lechner,&nbsp;M. Merklein","doi":"10.1016/j.jajp.2025.100372","DOIUrl":"10.1016/j.jajp.2025.100372","url":null,"abstract":"<div><div>Increasing demands for lightweight design and functional integration in modern production technology require innovative manufacturing processes. Multi-material systems offer a high potential to face these challenges by reducing weight while maintaining strength. A new approach of an orbital forming process to join dissimilar materials while simultaneously achieve a local thickening offers a reduced number of required parts since there is no need for auxiliary elements and high material efficiency due to near-net-shape design. In this context, this research provides the design and validation of a numerical simulation model for joining by orbital forming with local material accumulation in a single step. The hybrid component consists of an inner aluminum blank of EN AW-5754 and an outer steel ring made of DP600 both with an initial sheet thickness of 3.0 mm. The steel ring features cut-outs on the inside to provide a form closure in tangential direction. The primary aim of the simulation model is to predict and analyze the material flow during the forming process as well as the resulting stress states to evaluate the force closure. Furthermore, preliminary experimental investigations show a significant influence of the positioning of the steel cut-outs in relation to the locally thickened areas on the joint formation. This effect will be further analyzed using the numerical model to gain a deeper understanding of the cause-and-effect relations. Based on experimental investigations the numerical model will be validated by comparing the resulting sheet thickness distribution and the geometric and mechanical properties at the joint for several parameter combinations. The validated numerical model will then be used for an optimization of the joint positioning regarding the resulting material flow in the joint area. This approach provides a fundamental understanding on the mechanisms affecting this combined forming and joining process. In addition, this numerical tool offers an approach for designing local thickened hybrid components with various geometries and material combinations regarding the positioning of the joint in relation to the local material accumulation.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100372"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145925872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effect of stress ratio on fatigue life in a microstructure-sensitive fatigue model for ultimate grain refinement and initiation grain refinement of high-speed friction stir welding of AA6061-T6 to Cu","authors":"Esmaeil Mirmahdi ,&nbsp;Davood Afshari ,&nbsp;Masoud Mahmoodi","doi":"10.1016/j.jajp.2025.100367","DOIUrl":"10.1016/j.jajp.2025.100367","url":null,"abstract":"<div><div>The formation of an ultimate grain refinement (UGR) microstructure in high-speed friction stir welding (HSFSW) significantly improves the mechanical properties of dissimilar joints. This study shows that achieving this microstructure not only increases tensile strength by up to 177 MPa (equivalent to 80% of the base metal strength of Cu) but also substantially enhances the fatigue resistance of the samples. To investigate fatigue behavior, tests were conducted under three different stress ratios (<em>R</em> = 0.1, <em>R</em> = 0.5, and <em>R</em> = -1). A microstructure-sensitive fatigue model (MSF-FEM) was developed to simulate the fatigue life of samples in both the initial grain refinement (IGR, coarse-grained) and ultimate grain refinement (UGR, ultrafine-grained) states. Modeling and experimental results indicated that as the R increased (from -1 towards 0.1), fatigue life decreased, with the longest fatigue life observed under fully reversed loading conditions (<em>R</em> = -1). Under these conditions, the fatigue life of UGR samples reached 4.8 ☓ 10⁴ cycles, and IGR samples reached 3.5 ☓ 10⁴ cycles. The results showed that UGR samples, compared to IGR, had an average increase of over 100% in fatigue life at different R; specifically, this improvement reached 100% at <em>R</em> = 0.1, 167% at <em>R</em> = 0.5, and 37% at <em>R</em>=-1. These findings indicate the simultaneous and significant effect of optimal microstructure and loading conditions on increasing the fatigue life of HSFSW joints.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100367"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145926533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation of undercuts using cw-laser structuring as a surface pre-treatment for thermally joined metal-polymer hybrids","authors":"Benjamin Förster,&nbsp;Tobias Geis,&nbsp;Maurice Langer","doi":"10.1016/j.jajp.2026.100376","DOIUrl":"10.1016/j.jajp.2026.100376","url":null,"abstract":"<div><div>Pulsed laser systems are often used for surface pre-treatment prior to thermal direct joining, as they enable the creation of undercuts but their process speeds are too low for industrial applications. Continuous wave (cw) laser structuring is a promising alternative that can achieve high area rates of up to 200 mm²/s, representing a 10- to 100-fold increase. Although this allows high strengths to be generated in the shear direction, the strength in the normal direction is significantly lower due to the lack of undercuts. To address the latter problem, this study investigates three laser structuring strategies known as ‘oblique irradiation’, ‘hollowing bottom’ and ‘remelting top’. They aim to create defined undercuts to enhance mechanical interlocking between cold-rolled DP1000 steel and carbon fibre-reinforced PA6. The strategies were evaluated through metallographic analysis and mechanical testing in tensile shear and cross-lap tensile configurations. Among the approaches, the “Hollowing bottom” strategy demonstrated superior performance, achieving a maximum tensile shear strength of 30.3 MPa. A subsequent optimisation loop of this structuring strategy based on the principle of ‘design of experiments’ (DoE) revealed that the morphology of the undercut and reproducibility have a significant influence on the bond strength, especially under peel load. This resulted in a 40% increase in head tensile strength compared to the reference and to demonstrate the clear benefits of undercut surface structures. The findings highlight the potential of optimized cw-laser structuring to improve joint reliability in lightweight hybrid applications.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100376"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of secondary aluminum content on casting and weldability of high pressure die cast materials for sustainable automotive body concepts","authors":"Dirk Dittrich ,&nbsp;Dirk Lehmhus ,&nbsp;Marco Haesche ,&nbsp;Leonardo Fernandes Gomes ,&nbsp;Christoph Pille ,&nbsp;Axel Jahn ,&nbsp;Linda Ullmann ,&nbsp;Charlotte Graner","doi":"10.1016/j.jajp.2025.100361","DOIUrl":"10.1016/j.jajp.2025.100361","url":null,"abstract":"<div><div>Sustainability is becoming increasingly important in vehicle production. The e-mobility transition has shifted the CO₂ footprint from use to production phase, where secondary aluminum alloys in structural castings are known to offer significant CO₂ reduction potential. However, accumulation of copper, iron, manganese and zinc and the hydrogen content in the melt pose major challenges for casting and subsequent joining processes. In laser welding, dynamic modulation of intensity distributions in the weld pool can overcome the latter issue. In experimental studies covering high pressure die-cast AlSi10MnMg alloys with secondary material content levels ranging from 0 wt.-% and 58 wt.-% to 89 wt.-%, castability and weldability were investigated and the structural and mechanical properties of the joint determined. The results contribute to the optimization of sustainable car body production, providing a path towards cost-effective differential lightweight design solutions as economically, technologically and ecologically competitive alternatives to large-scale casting technologies (GigaCasting).</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100361"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145738200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Manufacturing and predicted fatigue behaviour of welds using the low-transformation-temperature (LTT) effect","authors":"M. Clemens ,&nbsp;M. Gamerdinger ,&nbsp;S. Olschok ,&nbsp;U. Reisgen ,&nbsp;T. Geers ,&nbsp;J. Voelkel ,&nbsp;H. Bartsch","doi":"10.1016/j.jajp.2026.100382","DOIUrl":"10.1016/j.jajp.2026.100382","url":null,"abstract":"<div><div>Fatigue strength often governs the design of welded steel. Conventional methods to improve fatigue performance, such as post-weld grinding or hammer peening, require additional manufacturing steps and are rarely applied in practice. An alternative approach is the Low-Transformation-Temperature (LTT) effect, which introduces compressive residual stresses via controlled martensitic phase transformations during welding. In this work, the submerged arc welding process was adapted to implement LTT welding using in situ alloying with commercially available high-alloy filler wires, enabling reproducible stress modification without additional post-treatment. Macroscopic weld inspection confirmed consistent geometry and defect-free seams, while EDS analysis revealed uniform chromium and nickel distribution. Hardness mapping showed a significant increase up to approximately 450 HV10, indicating successful martensitic transformation. Evaluation of an extended European fatigue database including LTT welds demonstrated fatigue strength improvements of 11 to 60 % for butt-welded joints and longitudinal stiffeners. Planned fatigue tests with precisely controlled cyclic loading and strain measurements will further quantify fatigue performance and scatter. These initial results confirm that LTT welding is a promising and cost-effective method to enhance fatigue strength in welded steel structures.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100382"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep learning-powered vision system for seam-tracking and gap width estimation in robotic laser welding","authors":"Matteo Moscatelli ,&nbsp;Mara Tanelli ,&nbsp;Ali Gökhan Demir","doi":"10.1016/j.jajp.2026.100377","DOIUrl":"10.1016/j.jajp.2026.100377","url":null,"abstract":"<div><div>The increasing adoption of robotic laser welding highlights the need for advanced seam-tracking systems to ensure precision, adaptability, and high-quality welds. Conventional methods struggle with fixturing errors, part-to-part variations, thermal deformation, and challenges related to material reflectivity. This work presents a deep learning-based vision system designed for real-time seam tracking and gap width estimation, addressing these limitations by leveraging state-of-the-art computer vision techniques. The system employs the YOLO (You Only Look Once) architecture for seam detection and a MobileNet-based Convolutional Neural Network (CNN) for gap width estimation, ensuring robust performance under variable lighting conditions and reflective surfaces. By processing coaxial images acquired during welding processes, the system accurately identifies the seam position and discretizes the trajectory into a sequence of key points. This information can then be used for further processing or integration with robotic motion control strategies. Experimental validation on an industrial robotic laser welding setup demonstrates the system’s capability to enhance tracking precision, minimize positioning errors, and support high-speed welding operations. The results confirm that deep learning-based vision systems play a crucial role in advancing autonomous robotic welding, increasing flexibility and efficiency in smart manufacturing.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"13 ","pages":"Article 100377"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146188468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Surface cracks repair in AA6061-T6 aluminum alloys using friction stir processing” [Journal of Advanced Joining Processes (2025) /100340]","authors":"Fadi Al-Badour ,&nbsp;Ahmad H. Bawagnih ,&nbsp;Ahmed Ali ,&nbsp;Rami K. Suleiman ,&nbsp;Necar Merah","doi":"10.1016/j.jajp.2025.100346","DOIUrl":"10.1016/j.jajp.2025.100346","url":null,"abstract":"","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"12 ","pages":"Article 100346"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissimilar TLP bonding of X-45/Hastelloy X superalloys using BNi-2 filler metal: Microstructural evolution and mechanical behaviors","authors":"A. Yarmou shamsabadi ,&nbsp;M. Farvizi ,&nbsp;L. Nikzad ,&nbsp;A. Malekan","doi":"10.1016/j.jajp.2025.100335","DOIUrl":"10.1016/j.jajp.2025.100335","url":null,"abstract":"<div><div>This article explores the dissimilar joining of two commonly utilized superalloys, X-45 and Hastelloy X (HX), through the Transient Liquid Phase (TLP) bonding technique using BNi-2 filler metal. The TLP process was performed at 1050 °C for varying durations (5–60 min). Microstructural analyses indicated that longer holding times at 1050 °C alongside the diffusion of Melting Point Depressant (MPD) elements into the base materials led to the completion of isothermal solidification and the elimination of the eutectic structure from the Athermally Solidified Zone (ASZ). The MPD elements exhibited varying diffusion rates across the joint's two sides. Increased diffusion of elements on the Hastelloy X side resulted in denser and more widespread precipitates than on the opposite side of the joint, although this region produced harder precipitates. To analyze the connection between microstructure and mechanical properties, a combination of microhardness and shear testing was utilized. Shear tests revealed two distinct types of fractures for joints formed over different durations: one type occurred when isothermal solidification was not completed, resulting in a cleavage fracture with low shear strength and weak bonding due to brittle eutectic compounds in the ASZ, while the other happened when isothermal solidification was complete, showing ductile fracture from the Diffusion Affected Zone (DAZ) that had the highest hardness following ASZ removal. The increased density of precipitates and broader precipitation zone on the HX side promote crack propagation along the boride-rich grain boundaries in this region, ultimately leading to the final fracture.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"12 ","pages":"Article 100335"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of precipitation kinetics during refill friction stir spot welding and post-weld heat treatments in AA7050 using SAXS and numerical modeling","authors":"Susanne Henninger ,&nbsp;Rupesh Chafle ,&nbsp;Niklaas Becker ,&nbsp;Camila C. de Castro ,&nbsp;Benjamin Klusemann ,&nbsp;Martin Müller ,&nbsp;Peter Staron","doi":"10.1016/j.jajp.2025.100365","DOIUrl":"10.1016/j.jajp.2025.100365","url":null,"abstract":"<div><div>The impact of the refill friction stir spot welding process (refill FSSW) on precipitates in a high-strength AA7050-T7651 alloy is studied. Cross-sections of the welded samples are analyzed via small-angle X-ray scattering (SAXS), yielding 2D maps of spatial distributions of precipitate volume fraction and mean radius. The welding plunge times are varied during refill FSSW, leading to an increase in the width of the heat-affected zone (HAZ) with increase in energy input. The mean radius of precipitates increases above 25 nm at the edges of the stir zone (SZ) and thermo-mechanically affected zone (TMAZ). Dissolution and growth of <span><math><mi>η</mi></math></span>-precipitates in the HAZ are measured in-situ and are successfully modeled with the PanPrecipitation software. Moreover, the effect of various post-weld heat treatments (PWHT) on the precipitate distribution in the weld is analyzed. Reprecipitation in the HAZ is seen already after short aging times. After 20 min, the volume fraction increases all over the HAZ and nearly reaches the volume fraction of the base material. In the SZ/TMAZ, GP zones are formed through natural aging after welding and the PWHT lead to phase transformations and an increase in volume fraction and precipitate growth. Precipitates grow to a size of 2.5 nm after PWHT at 120 ℃ and 6.5 nm at 163 ℃. Thus, the formation of <span><math><mrow><msup><mrow><mi>η</mi></mrow><mrow><mo>′</mo></mrow></msup><mo>+</mo><mi>η</mi></mrow></math></span>-phase is expected after PWHT. Hardness measurements show that the PWHT lead to a hardness increase in the SZ and outer HAZ, but a minimum remains in the TMAZ/HAZ, where precipitates coarsened during welding. No significant changes in the weld zone features and the corresponding microstructure are observed between the as-welded and PWHT joints, indicating that the time–temperature conditions do not induce transformations such as grain growth and/or static recrystallization.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"12 ","pages":"Article 100365"},"PeriodicalIF":4.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}