Journal of Advanced Joining Processes最新文献_第2页

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 : 2026-06-01 Epub 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 : 2026-06-01 Epub 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

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 : 2026-06-01 Epub 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

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 : 2026-06-01 Epub 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

Influence of secondary aluminum content on casting and weldability of high pressure die cast materials for sustainable automotive body concepts 二次铝含量对可持续汽车车身概念高压压铸材料铸造和可焊性的影响

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-06-01 Epub Date: 2025-11-28 DOI: 10.1016/j.jajp.2025.100361

Dirk Dittrich , Dirk Lehmhus , Marco Haesche , Leonardo Fernandes Gomes , Christoph Pille , Axel Jahn , Linda Ullmann , Charlotte Graner

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).

可持续性在汽车生产中变得越来越重要。电动汽车的转型已经将二氧化碳足迹从使用阶段转移到生产阶段，而结构铸件中的二次铝合金被认为具有显著的二氧化碳减排潜力。然而，铜、铁、锰和锌的积累以及熔体中的氢含量对铸造和随后的连接工艺构成了重大挑战。在激光焊接中，动态调制熔池的强度分布可以克服后一个问题。在高压压铸AlSi10MnMg合金的实验研究中，二次材料含量从0 wt.-%到58 wt.-%到89 wt.-%，研究了浇注性和可焊性，并确定了接头的结构和机械性能。研究结果有助于优化可持续的车身生产，为实现具有成本效益的差异化轻量化设计解决方案提供了一条道路，作为大规模铸造技术（GigaCasting）在经济、技术和生态方面具有竞争力的替代品。

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引用次数: 0

Manufacturing and predicted fatigue behaviour of welds using the low-transformation-temperature (LTT) effect 利用低变形温度效应制造和预测焊缝的疲劳行为

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-06-01 Epub Date: 2026-02-11 DOI: 10.1016/j.jajp.2026.100382

M. Clemens , M. Gamerdinger , S. Olschok , U. Reisgen , T. Geers , J. Voelkel , H. Bartsch

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.

焊接钢的疲劳强度往往决定着焊接钢的设计。提高疲劳性能的传统方法，如焊后磨削或锤击强化，需要额外的制造步骤，很少在实践中应用。另一种方法是低转变温度（LTT）效应，它在焊接过程中通过控制马氏体相变引入压缩残余应力。在这项工作中，采用埋弧焊工艺实现LTT焊接，使用市售的高合金填充焊丝进行原位合金化，无需额外的后处理即可实现可重复的应力修改。宏观焊缝检查证实焊缝几何形状一致且无缺陷，EDS分析显示铬和镍分布均匀。硬度图显示，在大约450 HV10时，硬度显著增加，表明马氏体相变成功。包括LTT焊接在内的扩展欧洲疲劳数据库的评估表明，对接焊接接头和纵向加强筋的疲劳强度提高了11%至60%。计划的疲劳试验与精确控制的循环加载和应变测量将进一步量化疲劳性能和分散。这些初步结果证实了LTT焊接是提高焊接钢结构疲劳强度的一种有前途和经济效益的方法。

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引用次数: 0

Deep learning-powered vision system for seam-tracking and gap width estimation in robotic laser welding 基于深度学习的机器人激光焊接焊缝跟踪与间隙宽度估计视觉系统

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2026-06-01 Epub Date: 2026-01-30 DOI: 10.1016/j.jajp.2026.100377

Matteo Moscatelli , Mara Tanelli , Ali Gökhan Demir

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.

越来越多地采用机器人激光焊接突出了对先进的焊缝跟踪系统的需求，以确保精度、适应性和高质量的焊接。传统的方法与夹具误差、零件之间的变化、热变形以及与材料反射率相关的挑战作斗争。这项工作提出了一个基于深度学习的视觉系统，设计用于实时接缝跟踪和间隙宽度估计，通过利用最先进的计算机视觉技术解决这些限制。该系统采用YOLO （You Only Look Once）架构进行接缝检测，并采用基于mobilenet的卷积神经网络（CNN）进行间隙宽度估计，确保在可变光照条件和反射表面下的稳健性能。该系统通过对焊接过程中获取的同轴图像进行处理，准确识别焊缝位置，并将轨迹离散为一系列关键点。然后，这些信息可以用于进一步处理或与机器人运动控制策略集成。工业机器人激光焊接装置的实验验证表明，该系统能够提高跟踪精度，最大限度地减少定位误差，并支持高速焊接操作。研究结果证实，基于深度学习的视觉系统在推进自主机器人焊接、提高智能制造的灵活性和效率方面发挥着至关重要的作用。

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引用次数: 0

Corrigendum to “Surface cracks repair in AA6061-T6 aluminum alloys using friction stir processing” [Journal of Advanced Joining Processes (2025) /100340] “用搅拌摩擦法修复AA6061-T6铝合金表面裂纹”的勘误表[高级连接工艺杂志(2025)/100340]

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-01 Epub Date: 2025-09-17 DOI: 10.1016/j.jajp.2025.100346

Fadi Al-Badour , Ahmad H. Bawagnih , Ahmed Ali , Rami K. Suleiman , Necar Merah

引用次数: 0

IF 4 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Advanced Joining Processes

Pub Date : 2025-12-01 Epub Date: 2025-07-26 DOI: 10.1016/j.jajp.2025.100335

A. Yarmou shamsabadi , M. Farvizi , L. Nikzad , A. Malekan

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.

本文利用BNi-2填充金属，通过瞬态液相（TLP）连接技术，研究了两种常用的高温合金X-45和哈氏合金X （HX）的异种连接。TLP过程在1050°C下进行，持续时间不同（5-60分钟）。显微组织分析表明，随着熔点抑制剂（MPD）元素向基材的扩散，在1050℃下保温时间延长，完成了等温凝固，消除了热固化区（ASZ）的共晶组织。MPD元素在关节两侧表现出不同的扩散速率。元素在哈氏合金X侧的扩散增加导致了比在接头另一侧更密集和更广泛的析出物，尽管该区域产生了更硬的析出物。为了分析微观组织与力学性能之间的关系，采用显微硬度和剪切试验相结合的方法。剪切试验显示，在不同时间形成的节理有两种不同类型的断裂：一种类型发生在等温凝固未完成时，由于ASZ中脆性共晶化合物的存在，导致剪切强度低、结合弱的解理断裂；另一种类型发生在等温凝固完成时，显示扩散影响区（DAZ）的韧性断裂，该区域在ASZ去除后具有最高的硬度。HX侧析出相密度增大，析出带变宽，促使裂纹沿该区域富含硼化物的晶界扩展，最终导致断裂。

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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 Epub Date: 2025-11-28 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。

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引用次数: 0