Journal of Advanced Joining Processes最新文献

Generation of undercuts using cw-laser structuring as a surface pre-treatment for thermally joined metal-polymer hybrids 利用激光结构作为热连接金属-聚合物杂化材料表面预处理的下切孔的产生

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-01-22 DOI: 10.1016/j.jajp.2026.100376

Benjamin Förster, Tobias Geis, Maurice Langer

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.

脉冲激光系统通常用于热直接连接之前的表面预处理，因为它们可以产生凹口，但其处理速度对于工业应用来说太低。连续波（cw）激光结构是一种很有前途的替代方案，可以实现高达200 mm²/s的高面积率，代表10到100倍的增长。虽然这允许在剪切方向上产生高强度，但由于缺乏下切槽，在法向上的强度显着降低。为了解决后一个问题，本研究探讨了三种激光结构策略，即“斜照射”，“空心底部”和“重熔顶部”。他们的目标是创造明确的切口，以加强冷轧DP1000钢和碳纤维增强PA6之间的机械联锁。通过金相分析和拉伸剪切和交叉搭接拉伸配置的力学测试来评估这些策略。其中，“挖空底部”策略表现出较好的性能，最大抗拉剪切强度达到30.3 MPa。基于“实验设计”（DoE）原则的这种结构策略的后续优化循环表明，凹边的形态和可重复性对粘结强度有重大影响，特别是在剥离载荷下。与参考材料相比，这使得封头抗拉强度提高了40%，并证明了凹边表面结构的明显优势。研究结果强调了优化的cw-激光结构在提高轻型混合应用中关节可靠性方面的潜力。

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引用次数: 0

Factory simulation of adhesive bonding processes considering pot-life-induced waste 工厂模拟胶粘剂粘合过程，考虑罐寿命引起的浪费

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-01-09 DOI: 10.1016/j.jajp.2026.100375

V Ginster , A Weigert , MK Heym , CJA Beier , A Schiebahn , S Galka

The simulation of production systems in the planning phase is an established tool for evaluating system performance under dynamic conditions (Da Silva et al., 2018). When planning a production system that includes time-critical processes such as adhesive bonding, exceeding time constraints (e.g., excessive lead times relative to the adhesive pot-life) can lead to product rejection and scrap. These risks should be analyzed by means of simulation, as it enables the consideration of stochastic effects such as random machine breakdowns, which significantly influence product lead times.

This study focuses on the production of adhesively bonded electrolyzer-cells. Due to the cell design, several handling and stacking operations must be carried out between adhesive application and final joining, so that immediate joining is not feasible and pot-life-induced scrap becomes a critical risk factor. We therefore conducted an exploratory investigation that combines experimental pot-life characterization with discrete-event simulation of a planned electrolyzer-cell production system.

A two-component epoxy adhesive was characterized using differential scanning calorimetry with kinetic analysis, rotational rheometry, and 90° peel tests on application-representative joints. Based on these tests, an application-specific pot-life was derived and implemented as a time-dependent quality criterion in the discrete-event simulation model. A full-factorial simulation study with varied buffer size and mean time to repair at a station availability of 98 % was carried out. The results demonstrated a pronounced trade-off between throughput and pot-life-induced waste and identified a buffer capacity of one and short repair times as the most favorable configuration. Extending pot-life due to different processing temperatures substantially reduced scrap, highlighting the benefit of integrating curing kinetics and dynamic simulation in early-stage production system design for time-critical adhesive processes.

计划阶段的生产系统模拟是动态条件下评估系统性能的既定工具（Da Silva等人，2018）。当规划一个生产系统，包括时间关键的过程，如粘合剂粘合，超过时间限制（例如，相对于粘合剂罐寿命的过多的交货时间）可能导致产品报废和报废。这些风险应该通过模拟来分析，因为它可以考虑随机效应，如随机机器故障，这对产品的交货时间有很大的影响。本研究的重点是粘接电解槽的生产。由于电池的设计，在粘合剂应用和最终连接之间必须进行多次处理和堆叠操作，因此立即连接是不可实现的，并且罐寿命引起的废料成为一个关键的风险因素。因此，我们进行了一项探索性研究，将实验罐寿命特征与计划的电解槽生产系统的离散事件模拟相结合。采用差示扫描量热法、动力学分析、旋转流变学和90°剥离试验对一种双组分环氧胶粘剂进行了表征。在这些测试的基础上，导出了特定应用的油罐寿命，并在离散事件仿真模型中实现了与时间相关的质量准则。一个全因子模拟研究，在不同的缓冲大小和平均修理时间，站的可用性为98%。结果表明，在吞吐量和罐寿命引起的浪费之间存在明显的权衡，并确定缓冲容量为1，修复时间短是最有利的配置。由于不同的处理温度延长了锅的寿命，大大减少了废料，突出了在时间关键的粘合过程的早期生产系统设计中集成固化动力学和动态模拟的好处。

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引用次数: 0

Butt-joint welding process of PVC Profiles: Numerical modelling, experimental validation and insights into material behaviour and flow dynamics PVC型材的对接焊接过程：数值模拟、实验验证以及对材料行为和流动动力学的见解

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-01-06 DOI: 10.1016/j.jajp.2026.100374

Riccardo Panciroli , Daniele Chiappini , Roberto Palazzetti

Polyvinyl chloride (PVC) forming operations are typified by large deformations, free-surface condition, complex conjugate heat transfer, and intricate contact phenomena. This study focuses on numerical modelling of the forming process that occurs beneath the butt-joint welding of polymeric profiles to offer a comprehensive understanding of how process parameters and boundary conditions influence the final weld. Numerical simulations are based on arbitrary and coupled Lagrangian and Eulerian models, which incorporate viscoelasticity, heat transfer, external forces, and free-surface flow. Due to the extensive temperature range encountered during the process, during heating the material transitions from a linear elastic state to a low-viscosity fluid. Consequently, the model has been developed to simultaneously solve for both solid and free-surface fluid conditions, and PVC has been modelled as a temperature-dependent viscoelastic solid, exhibiting Newtonian-like fluid characteristics under high temperatures. The proposed numerical solution methodology is employed to offer insights into the physics of the butt-welding process, widely utilised within industry. Two distinct configurations have been modelled to study material flow during the process: with and without a rigid constrain that prevents the material from moving freely upwards. These simulations aim to illuminate the impact of boundary conditions and physical constraints on the welding process and material behaviour.

聚氯乙烯（PVC）成型操作具有大变形、自由表面条件、复杂的共轭传热和复杂的接触现象等特点。本研究的重点是对聚合物型材对接焊接下的成形过程进行数值模拟，以全面了解工艺参数和边界条件如何影响最终焊缝。数值模拟是基于任意和耦合拉格朗日和欧拉模型，其中包括粘弹性，传热，外力和自由表面流动。由于在加热过程中遇到的温度范围很广，在加热过程中材料从线性弹性状态转变为低粘度流体。因此，该模型可以同时求解固体和自由表面流体条件，并且PVC已被建模为温度依赖的粘弹性固体，在高温下表现出类似牛顿的流体特性。所提出的数值解决方法被用来提供对焊接过程的物理学的见解，广泛应用于工业中。模拟了两种不同的结构来研究过程中的材料流动：有和没有阻止材料自由向上移动的刚性约束。这些模拟旨在阐明边界条件和物理约束对焊接过程和材料行为的影响。

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引用次数: 0

Investigation of joint shapes for friction welding between 7075-T6 Al alloy and low carbon steel with an insert metal of pure Ti 7075-T6铝合金与插入纯钛低碳钢摩擦焊接接头形状的研究

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-01-01 DOI: 10.1016/j.jajp.2026.100373

Masaaki Kimura , Yuki Tamakoshi , Masahiro Kusaka , Koichi Kaizu

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.

7075-T6型铝合金（AA7075）与低碳钢（LCS）之间的直接摩擦焊接尤其困难，因为在焊接过程中，裂纹往往在AA7075闪光中形成并传播到焊缝界面。本研究采用商业纯钛（CP-Ti）作为插入金属，在单步工艺中对AA7075和LCS的同时摩擦焊接进行了研究，目的是实现AA7075闪光处无裂纹的连接。仅通过改变CP-Ti插入金属的形状不能获得无裂纹的AA7075闪光接头。然而，当AA7075侧的焊缝直径大于CP-Ti插入金属的直径时，并使用合适形状的CP-Ti插入金属，并在AA7075侧有凹槽时，可以防止闪裂。接头的抗拉强度高于LCS母材的屈服强度；具体来说，锻造压力为400mpa时，LCS母材的抗拉强度约为83%。尽管有这些改进，但由于即使在高锻造压力下制造接头，LCS侧的邻近区域也没有太大变形，因此无法实现LCS母材内部发生断裂等良好连接。因此，进一步优化CP-Ti镶块金属形状对于促进LCS侧的更大变形和提高整体接头特性至关重要。

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引用次数: 0

Numerical investigation of an orbital forming process to join dissimilar materials with local material accumulation 不同材料与局部物质堆积连接轨道成形过程的数值研究

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-29 DOI: 10.1016/j.jajp.2025.100372

A. Harms, D. Römisch, D. Reisacher, M. Lechner, M. Merklein

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.

现代生产技术对轻量化设计和功能集成的要求越来越高，这就要求创新的制造工艺。多材料系统通过在保持强度的同时减轻重量，为应对这些挑战提供了很大的潜力。一种轨道成形工艺的新方法，在连接不同材料的同时实现局部增厚，减少了所需零件的数量，因为不需要辅助元件，并且由于近净形状设计，材料效率高。在此背景下，本研究提供了一个单步轨道成形与局部材料积累连接的数值模拟模型的设计和验证。混合组件由EN AW-5754的内铝毛坯和DP600的外钢圈组成，初始板材厚度均为3.0 mm。钢环的内部有切口，在切向上形成封闭。仿真模型的主要目的是预测和分析成形过程中的材料流动以及由此产生的应力状态，以评估力闭合。此外，初步的实验研究表明，与局部加厚区域相关的钢切口位置对节理形成有显著影响。我们将使用数值模型进一步分析这种影响，以更深入地了解因果关系。在实验研究的基础上，通过比较不同参数组合下得到的板料厚度分布和接头处的几何力学性能，对数值模型进行验证。验证后的数值模型将用于优化连接区域内材料流的连接定位。这种方法提供了对影响这种组合成形和连接过程的机制的基本理解。此外，该数值工具还为设计具有各种几何形状和材料组合的局部加厚混合部件提供了一种方法，该方法涉及到与局部材料积累相关的接头定位。

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引用次数: 0

AI-based monitoring system for real-time defect detection in wire arc additive manufacturing 基于人工智能的电弧增材制造缺陷实时检测系统

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-26 DOI: 10.1016/j.jajp.2025.100371

J.E. Tapia Cabrera, F. Groschupp, F. Riegger, M.F. Zaeh

The high flexibility of additive manufacturing (AM) enables the repair of components with complex geometries, contributing to the sustainability of the economy by reducing waste and increasing product lifetime. Wire arc additive manufacturing (WAAM) is well-suited for repair due to the high deposition rates compared to other AM technologies. Moreover, the automation potential of WAAM offers a promising opportunity for increasing productivity. However, the automated repair presents new challenges for quality assurance. During the deposition of successive layers, defects, such as a lack of fusion between adjacent weld beads, may be concealed within the parts. Due to their impact on the mechanical properties, such discontinuities constitute non-conformities and require part rejection. Therefore, a real-time monitoring system is required to detect lack of fusion defects and to ensure the reliable performance of the repaired components. Weld pool imaging provides detailed insights into process anomalies. Nonetheless, the harsh welding environment degrades the data quality and requires advanced imaging algorithms to extract features for a reliable analysis. The artificial intelligence (AI) architecture “You Only Look Once” (YOLO) allows for a robust detection performance and real-time capability with its one-stage approach for object detection. In this work, a monitoring system using two sequentially coupled YOLO-based models was developed. First, a detection model identifies the lack of fusion defects within the weld pool images, producing bounding boxes around the detected areas. These bounding boxes are then used as an input for a segmentation model, which provides a more precise delineation of the defects within the identified regions. The models were evaluated on unseen data, achieving a recall of over 90 % while maintaining real-time capability. This result showed the high potential of AI-based monitoring systems for real-time defect detection in WAAM to ensure the quality of the repaired components.

增材制造（AM）的高灵活性使具有复杂几何形状的部件得以修复，通过减少浪费和延长产品寿命，为经济的可持续性做出贡献。由于与其他增材制造技术相比，电弧增材制造（WAAM）具有较高的沉积速率，因此非常适合修复。此外，WAAM的自动化潜力为提高生产力提供了一个有希望的机会。然而，自动化维修对质量保证提出了新的挑战。在连续层的沉积过程中，缺陷，如相邻焊珠之间缺乏熔合，可能隐藏在零件内部。由于它们对机械性能的影响，这种不连续性构成不合格，需要零件报废。因此，需要一个实时监测系统来检测融合缺陷的缺失，并保证被修复部件的可靠性能。焊接池成像提供了对工艺异常的详细见解。然而，恶劣的焊接环境会降低数据质量，需要先进的成像算法来提取特征以进行可靠的分析。人工智能（AI）架构“You Only Look Once”（YOLO）采用单阶段对象检测方法，具有强大的检测性能和实时能力。在这项工作中，开发了一个使用两个顺序耦合的基于yolo的模型的监测系统。首先，检测模型识别焊池图像中缺乏融合缺陷，在检测区域周围产生边界框。然后将这些边界框用作分割模型的输入，该模型提供了对已识别区域内缺陷的更精确的描述。这些模型在未见过的数据上进行了评估，在保持实时能力的同时，实现了超过90%的召回。这一结果显示了基于人工智能的监测系统在WAAM中用于实时缺陷检测以确保被修复部件的质量的巨大潜力。

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引用次数: 0

Use of expandable graphite as debonding on demand technology between glass fibre reinforced polyamide 6 and aluminium 使用可膨胀石墨作为玻璃纤维增强聚酰胺6与铝之间的按需剥离技术

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-23 DOI: 10.1016/j.jajp.2025.100369

Abdelghani Laachachi , Oussema Kachouri , Julian Berndt , Gregor Zucker , Camilo Zopp , Jens Bartelt , Ahmed Makradi

A heat triggered debonding-on-demand thermoset-based adhesive is developed to join the glass fiber reinforced thermoplastic polyamide-6 to aluminium alloy sheet. The hybrid composite interface debonding mechanism is heat triggered at the end-of-life of the hybrid composite toward recycling of its components. The debonding-on-demand adhesive joint consist of an ARALDITE® brittle thermoset variant functionalized with 10% Expandable Graphite. TGA analysis and shear lab test are conducted to evaluate the effect of the Expandable Graphite on the degradation and mechanical performances of the ARALDITE® resin. Once validated the developed debonding-on-demand solution is up-scaled to a U-shape part made on inverse hybrid laminates.

研制了一种热触发脱粘热固性粘接剂，用于玻璃纤维增强热塑性聚酰胺-6与铝合金板的粘接。杂化复合材料界面剥离机制是在杂化复合材料寿命结束时热触发的，以回收其组分。按需脱粘粘合剂接头由ARALDITE®脆性热固性变体组成，该变体具有10%可膨胀石墨的功能化。通过TGA分析和剪切实验，评价了可膨胀石墨对ARALDITE®树脂降解和力学性能的影响。一旦验证，开发的按需脱粘解决方案将扩展到在反向混合层压板上制造的u形部件。

引用次数: 0

Quality assurance of clinched joints using explainable machine learning 使用可解释的机器学习来保证固定关节的质量

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-17 DOI: 10.1016/j.jajp.2025.100368

Johannes Gerritzen , Kunal Chopra , Gregor Reschke , Andreas Hornig , Alexander Brosius , Maik Gude

Quality assurance (QA) of clinched joints is predominantly performed by destructive testing. Recently, non-destructive evaluation (NDE) methods received increasing attention as a potential alternative. However, the inherently indirect measurement of underlying effects poses a significant challenge to its broader application. To tackle this, two experimental data sets, containing a total of 43 potential process deviations and defects are established using transient dynamic analysis (TDA). On these, several machine learning (ML) models are trained to detect the underlying deviations. The best-in-class model is used to identify a frequency band at which a classification accuracy of 88.58% across all 43 classes is achieved. Further analysis of the most discriminative model features reveals the importance of measuring both excitation as well as specimen response. This lays the foundation for further research towards defect specific in-line measurements of mechanical joints, further improving joint reliability.

紧固接头的质量保证（QA）主要是通过破坏性检测来完成的。近年来，无损评价（NDE）方法作为一种潜在的替代方法受到越来越多的关注。然而，对潜在影响的固有间接测量对其更广泛的应用构成了重大挑战。为了解决这个问题，使用瞬态动态分析（TDA）建立了两个实验数据集，其中包含总共43个潜在的工艺偏差和缺陷。在这些基础上，训练几个机器学习（ML）模型来检测潜在的偏差。使用同类最佳模型来确定一个频带，在该频带上，所有43个类别的分类准确率达到88.58%。进一步分析最具判别性的模型特征，揭示了同时测量激励和试样响应的重要性。这为进一步研究针对机械接头缺陷的在线测量奠定了基础，进一步提高了接头的可靠性。

引用次数: 0

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 AA6061-T6 - Cu高速搅拌摩擦焊极限细化和起始细化细观疲劳模型中应力比对疲劳寿命的影响

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-17 DOI: 10.1016/j.jajp.2025.100367

Esmaeil Mirmahdi , Davood Afshari , Masoud Mahmoodi

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 (R = 0.1, R = 0.5, and R = -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 (R = -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 R = 0.1, 167% at R = 0.5, and 37% at R=-1. These findings indicate the simultaneous and significant effect of optimal microstructure and loading conditions on increasing the fatigue life of HSFSW joints.

高速搅拌摩擦焊接（HSFSW）中形成的终极晶粒细化（UGR）组织显著改善了异种接头的力学性能。研究表明，实现这种微观结构不仅使试样的抗拉强度提高了177 MPa（相当于铜母材强度的80%），而且大大提高了试样的抗疲劳性能。为了研究疲劳行为，在三种不同的应力比（R = 0.1, R = 0.5和R = -1）下进行了试验。建立了微结构敏感疲劳模型（MSF-FEM），模拟试样在初始晶粒细化（粗晶态）和最终晶粒细化（超细晶态）状态下的疲劳寿命。模型和实验结果表明，随着R的增大（从-1到0.1），疲劳寿命减小，在完全反向加载条件下疲劳寿命最长（R = -1）。在此条件下，UGR试样的疲劳寿命达到4.8 104次，IGR试样的疲劳寿命达到3.5 104次。结果表明：不同R值下，UGR试样的疲劳寿命比IGR试样平均提高100%以上；具体来说，在R= 0.1时，这种改善达到100%，在R= 0.5时达到167%，在R=-1时达到37%。这些结果表明，优化组织和加载条件对提高HSFSW接头疲劳寿命有同步且显著的影响。

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引用次数: 0

Analysis of precipitation kinetics during refill friction stir spot welding and post-weld heat treatments in AA7050 using SAXS and numerical modeling 利用SAXS和数值模拟分析AA7050填充搅拌摩擦点焊和焊后热处理过程中析出动力学

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-01 DOI: 10.1016/j.jajp.2025.100365

Susanne Henninger , Rupesh Chafle , Niklaas Becker , Camila C. de Castro , Benjamin Klusemann , Martin Müller , Peter Staron

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

η

-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

η^{'} + η

-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.

研究了再填充搅拌摩擦点焊工艺（FSSW）对高强AA7050-T7651合金析出相的影响。通过小角x射线散射（SAXS）对焊接试样的横截面进行分析，得到析出相体积分数和平均半径的二维空间分布图。随着能量输入的增加，热影响区宽度也随之增大。在搅拌区（SZ）和热机械影响区（TMAZ）边缘，沉淀的平均半径增加到25 nm以上。在原位测量了热影响区内η相的溶解和生长，并成功地用PanPrecipitation软件进行了模拟。此外，还分析了不同焊后热处理对焊缝中析出相分布的影响。在短时效时间后，HAZ内的再沉淀已经出现。20 min后，热影响区内的体积分数逐渐增大，接近基材的体积分数。在SZ/TMAZ中，焊接后自然时效形成GP区，PWHT导致相变、体积分数增加和析出相生长。120℃PWHT后析出相尺寸为2.5 nm， 163℃PWHT后析出相尺寸为6.5 nm。因此，PWHT后η′+η相的形成是预期的。硬度测量表明，PWHT导致SZ和外HAZ的硬度增加，但在TMAZ/HAZ中硬度最小，在焊接过程中析出物变粗。焊态和PWHT接头之间的焊缝区特征和相应的组织没有明显变化，表明时间-温度条件不会诱导晶粒长大和/或静态再结晶等转变。

{"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 , Rupesh Chafle , Niklaas Becker , Camila C. de Castro , Benjamin Klusemann , Martin Müller , 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}

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