International Journal of Machine Tools & Manufacture最新文献

{"title":"How does ultrasonic cutting affect the macroscopic deformation and microstructure evolution of fibre-reinforced titanium matrix composites?","authors":"Liyu Wang ,&nbsp;Xiaoxing Gao ,&nbsp;Qiaosheng Feng ,&nbsp;Xinlong Guo ,&nbsp;Zhen Li ,&nbsp;Wenzhao An ,&nbsp;Weiwei Xu ,&nbsp;Qilin Li ,&nbsp;Songmei Yuan","doi":"10.1016/j.ijmachtools.2024.104245","DOIUrl":"10.1016/j.ijmachtools.2024.104245","url":null,"abstract":"<div><div>Continuous silicon carbide (SiC) fibre-reinforced titanium (Ti) matrix composites (SiC_f/Ti) possess exceptional properties, making them promising for aerospace applications. Continuous SiC fibres significantly enhance the axial tensile strength of SiC_f/Ti compared to traditional Ti alloys. To utilise this material fully, its axial dimensions are fixed during manufacturing, but the outer Ti matrix layer must be thinned to meet structural accuracy requirements. Thinning often leads to interfacial cracking and fibre breakage owing to machining stress, which presents a major challenge in manufacturing. The deformation mechanism during thinning is unclear and the lack of low-stress thinning methods significantly limits the potential applications of SiC_f/Ti. This study investigates the macroscopic deformation and microstructural evolution of SiC_f/Ti under ultrasonic cutting (UC) through orthogonal experiments. Compared with conventional cutting (CC), UC reduces cutting force by 20 % and surface residual stress by 60 %, while increasing subsurface residual stress and nano-hardness. The acoustic softening effect in UC reduces cutting force and surface stress, while high-frequency stress waves elevate subsurface stress. Digital image correlation (DIC) analysis reveals that the combined effects of loading and unloading cycles during UC produce an elastic recovery strain, reducing the overall deformation in SiC_f/Ti during machining. Additionally, UC promotes grain refinement in the outer Ti layer of SiC_f/Ti and induces a stress concentration at the α-Ti and β-Ti interface, facilitating the transformation of α-Ti to β-Ti. The presence of SiC fibres amplifies the effects of the ultrasonic energy, accelerating dislocation diffusion and annihilation, promoting dynamic recrystallisation, and reducing the dislocation density between the fibres. Moreover, UC homogenises and realigns the stress field at the SiC_f/Ti interface, making the composition and structure of the interface more uniform and reducing interfacial damage. This study provides theoretical and practical insights into low-stress thinning, paving the way for broader applications of SiC_f/Ti in advanced structural components.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"205 ","pages":"Article 104245"},"PeriodicalIF":14.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142929193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Super-resolution laser machining","authors":"Jiaxu Huang,&nbsp;Kang Xu,&nbsp;Shaolin Xu","doi":"10.1016/j.ijmachtools.2025.104246","DOIUrl":"10.1016/j.ijmachtools.2025.104246","url":null,"abstract":"<div><div>Super-resolution laser machining represents a cutting-edge advancement in precision manufacturing, striving to approach or even exceed the optical diffraction limit to produce structures with exceptionally fine feature sizes, minimal heat-affected zones, and intricate freeform patterns. The present paper provides an overview of two principal approaches developed to achieve super-resolution: one is reducing the diffraction limit through the adoption of shorter laser wavelengths or advanced focusing techniques, and the other is surpassing the diffraction limit by advanced manipulation of the laser and its interactions with materials. With a deep investigation of the principles of these super-resolution laser machining methods, the review mainly explores the recent advancements in laser characteristics manipulation, materials innovation, and the integration of adaptive optics, high-speed laser scanning equipment, and feedback systems, all of which aim at enhancing machining resolution and broadening its applicability. Focusing on research frontiers and industrial applications, we also critically discussed future directions, potential problems, and possible solutions to smaller structure manufacturing regarding the light source, optical system, laser-matter interactions, and the surface evaluation methods. It also highlights the prospects for super-resolution laser machining, emphasizing its potential to transform precision manufacturing across industries.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"205 ","pages":"Article 104246"},"PeriodicalIF":14.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143136846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic-level insight into sequential evolution of nanocomposite carbon structures in femtosecond laser processing of diamond","authors":"Huili Han,&nbsp;Hao Liu,&nbsp;Jiaxu Huang,&nbsp;Pei Qiu,&nbsp;Jun Li,&nbsp;Bi Zhang,&nbsp;Shaolin Xu","doi":"10.1016/j.ijmachtools.2025.104247","DOIUrl":"10.1016/j.ijmachtools.2025.104247","url":null,"abstract":"<div><div>Diamond is an exceptional wide-bandgap semiconductor for electronics and quantum technologies. While femtosecond laser processing enables micro/nano fabrication of diamond, the dynamic atomic-level structural evolution during this process remains poorly understood, despite its critical impact on advanced applications. In this work, we investigate the multi-stage structural evolution of diamond under femtosecond laser irradiation, uncovering new scientific findings under laser-induced extreme conditions. The continuous input of pulse energy facilitates the rearrangement of local carbon atoms in the modified layer and partial phase transition layer, transitioning them from thermodynamically unstable to stable states. We introduce a sequential evolution pathway of nanocomposite carbon structures, and reinterpret the phenomenon previously broadly defined as “graphitization”. Specifically, the evolution of diaphite, diamond-OLC (onion-like carbon), and the transition from amorphous carbon to planar-oriented graphite are reported under femtosecond laser surface processing. These phase transitions are initiated by the rapid lattice heating, with their distribution influenced by near-field enhancement effects arisen from surface nanostructures. This work provides atomic-scale insights into diamond's response in femtosecond laser processing, offering a theoretical foundation for ultra-precision micro/nano fabrication of diamond and the development of functional carbon materials.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"206 ","pages":"Article 104247"},"PeriodicalIF":14.0,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143157268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding thermal-mechanical variations and resulting joint integrity of pressure-controlled linear friction welding of thin-steel sheets","authors":"Rishabh Shotri ,&nbsp;Takuya Miura ,&nbsp;Peihao Geng ,&nbsp;Yoshiaki Morisada ,&nbsp;Kohsaku Ushioda ,&nbsp;Hidetoshi Fujii","doi":"10.1016/j.ijmachtools.2024.104235","DOIUrl":"10.1016/j.ijmachtools.2024.104235","url":null,"abstract":"<div><div>Linear friction welding is a solid-state joining technology that bonds materials via friction heating and plastic deformation. This process is being extensively researched for welding metallic sheets with different dimensions; however, it involves difficulties in joining thin cross-sections due to extensive misalignment and unsteady plastic extrusion of softened materials at interfaces. This study introduces novel efforts for joining thin cross-sections through pressure-controlled oscillations and displacements, facilitating localized plastic flow essential for high-strength solid-state bond formation. This method is rare, and the results reveal base metal fractures in tensile-tested welded joints of 2 mm thick S45C steel sheets. The interfacial yielding at specific temperatures is obtained by applying pressure corresponding to the temperature-dependent strength of the material. Accordingly, the welding is attempted using a hydraulic-based clamping system designed to accommodate large sheet lengths while allowing precise control of the interface pressure and temperature to facilitate controlled material plastic discharge. However, the requisite joint evolution tracking remains infeasible due to the intricate weld designs and is instead uncovered through novel numerical investigations. Modeling simultaneous oscillations and forging displacement while maintaining pressure depicted the kinetics of continual interfacial deformation. The transient fluctuations in plastic stress and temperature increments distinguish the stages of forging under different conditions. The computed temperature vs. plastic strain and the measured change in interfacial microstructures from martensite to dynamically recrystallized very fine ferrite with fragmented small cementite explain the lower temperature welding for an increase in applied pressure, enhancing the understanding of linear friction welding of thin steel sections for industrial applications.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"204 ","pages":"Article 104235"},"PeriodicalIF":14.0,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of three-dimensional forces during additive friction stir deposition — How could force signals reveal the deposition quality?","authors":"Yiming Huang ,&nbsp;Qi Liu ,&nbsp;Kaiyue Zhang ,&nbsp;Mingyu Li ,&nbsp;Tianhao Yang ,&nbsp;Lijun Yang ,&nbsp;Lei Cui","doi":"10.1016/j.ijmachtools.2024.104234","DOIUrl":"10.1016/j.ijmachtools.2024.104234","url":null,"abstract":"<div><div>Additive friction stir deposition (AFSD) is a solid-phase forming technology based on microzone forging, which is essentially a force-driven additive manufacturing process. This work focuses on the effects of the AFSD parameters on the force signals and forming quality, which is highly important for optimizing the process parameters and controlling the forming quality. By analyzing the force features in the time‒frequency domain, the evolution mechanism of three-dimensional forces during AFSD was explored. A 3D scanner, scanning electron microscope (SEM) and electron backscatter diffraction (EBSD) were used to clarify the surface morphology and microstructures of the deposition layers. It was found that deposition defects were accompanied by a lack of plasticization or nonuniform deformation between the advancing side (AS) and the retreating side (RS). Moreover, the relationships among the process parameters, three-dimensional forces and deposition quality were investigated. It is proved that force signal can effectively reflect the deposition quality. A comprehensive prediction model based on three-dimensional force features was developed, achieving an accurate prediction of deposition quality. Furthermore, this work demonstrated the feasibility of AFSD quality control on the basis of force signals. The currently employed control strategies can be further extended to address the AFSD of large components in the future.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"204 ","pages":"Article 104234"},"PeriodicalIF":14.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards a differentiated understanding of process damping and the introduction of process stiffening effects","authors":"Florian Wöste ,&nbsp;Timo Platt ,&nbsp;Jonas Baumann ,&nbsp;Dirk Biermann ,&nbsp;Petra Wiederkehr","doi":"10.1016/j.ijmachtools.2024.104233","DOIUrl":"10.1016/j.ijmachtools.2024.104233","url":null,"abstract":"<div><div>The effect of process damping is an effective means to favorably influence the stability of machining processes. Its occurrence depends on the dynamic contact between the flank face of the tool and the workpiece surface. To specifically investigate the fundamentals of process damping effects in the context of process stabilization, different configurations of modified cutting tools were prepared and applied for this contribution. These modifications consisted of tools with conventional and functionally structured flank face chamfers and were expected to cause distinctly different interaction characteristics. While the use of conventional flank face chamfers was expected to cause a rather significant share of elastic deformation of workpiece material, the application of surface structures was intended to provoke an increased degree of dissipative, i.e., process damping effects due to plastic deformation of workpiece material. By conducting orthogonal cutting experiments using a sensor-integrated analogy setup, milling tests as well as representative simulation approaches, the fundamental interrelations of the dynamic interaction between the workpiece surface and tools with both conventional and structured chamfers were characterized. It was observed that a conventional flank face chamfer in contact with the workpiece surface causes predominantly elastic deformations of the workpiece material due to a relatively large contact area, resulting in distributed, low local contact stresses below the yield stress. These elastic deformations led to a temporary stiffening effect on the dynamic system significantly affecting its dynamic behavior, e.g., in form of increased vibration frequencies. In contrast, surface structures led to an increased share of plastic deformation due to concentrated contact stresses at the structure tips and, thus, to dissipative, i.e., damping effects. Based on the experimental and simulation-based results presented as part of this contribution, which are consistent with observations made in previous studies, a differentiated consideration of process damping as one of five methods for process stabilization is discussed. In this context, the introduction of process stiffening in addition to process damping as a stabilizing process inherent contact phenomenon is proposed for future consideration.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"204 ","pages":"Article 104233"},"PeriodicalIF":14.0,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing mechanisms of processing defect mitigation in laser powder bed fusion via shaped beams using high-speed X-ray imaging","authors":"Jiandong Yuan ,&nbsp;Qilin Guo ,&nbsp;Samuel J. Clark ,&nbsp;Luis I. Escano ,&nbsp;Ali Nabaa ,&nbsp;Minglei Qu ,&nbsp;Junye Huang ,&nbsp;Qingyuan Li ,&nbsp;Allen Jonathan Román ,&nbsp;Tim A. Osswald ,&nbsp;Kamel Fezzaa ,&nbsp;Lianyi Chen","doi":"10.1016/j.ijmachtools.2024.104232","DOIUrl":"10.1016/j.ijmachtools.2024.104232","url":null,"abstract":"<div><div>The laser powder bed fusion (LPBF) process utilizing a focused Gaussian-shaped beam faces challenges, including pore formation, melt pool fluctuation and liquid spattering. While beam shaping technology has been explored as a potential approach for defect mitigation, the beam-matter interaction dynamics during melting with shaped beams remain unclear. Here, we report the direct observation of ring-shaped beam-matter interaction dynamics, including pore formation, melt pool fluctuation and liquid spattering, and unveil defect mitigation mechanisms in ring-shaped beam laser powder bed fusion process. We find that, by spatially manipulating incident laser rays, the ring-shaped beam controls keyhole morphology, thereby managing the distribution of the reflected rays. This manipulation can effectively eliminate the formation of an unstable cavity at the keyhole tip, stabilizing the keyhole and mitigating keyhole pores. This enhanced keyhole stability effectively reduces the melt pool fluctuation, the formation of liquid breakup induced spatters and liquid droplet colliding induced large spatters in the laser powder bed fusion process. Additionally, the high-energy forefront of the ring-shaped beam effectively melts the powder bed, reducing agglomeration liquid spatter in the laser powder bed fusion process. The discovered defect mitigation mechanisms may guide the design of beam shaping strategies for simultaneously increasing the quality and productivity of metal additive manufacturing.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"204 ","pages":"Article 104232"},"PeriodicalIF":14.0,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining in situ synchrotron X-ray imaging and multiphysics simulation to reveal pore formation dynamics in laser welding of copper","authors":"T. Florian ,&nbsp;K. Schricker ,&nbsp;C. Zenz ,&nbsp;A. Otto ,&nbsp;L. Schmidt ,&nbsp;C. Diegel ,&nbsp;H. Friedmann ,&nbsp;M. Seibold ,&nbsp;P. Hellwig ,&nbsp;F. Fröhlich ,&nbsp;F. Nagel ,&nbsp;P. Kallage ,&nbsp;M. Buttazzoni ,&nbsp;A. Rack ,&nbsp;H. Requardt ,&nbsp;Y. Chen ,&nbsp;J.P. Bergmann","doi":"10.1016/j.ijmachtools.2024.104224","DOIUrl":"10.1016/j.ijmachtools.2024.104224","url":null,"abstract":"<div><div>Laser beam welding has emerged as a powerful tool for manufacturing copper components in electrical vehicles, electronic devices or energy storage, owing to its rapid processing capabilities. Nonetheless, the material’s high thermal conductivity and low absorption of infrared light can introduce process instabilities, resulting in defects such as pores. This study employs a hybrid approach that combines in situ synchrotron X-ray imaging with compressible multiphysics process simulation to elucidate pore-forming mechanisms during laser beam welding of copper. High-speed synchrotron X-ray imaging with an acquisition rate of 20,000 images/second facilitates the identification of relevant process regimes concerning pore formation during laser beam welding of copper with a wavelength of 1070 nm. Furthermore, in situ observations with high temporal and spatial resolution present a unique database for extensive validation of a multi-physics process simulation based on welding processes using different concentric intensity distributions. These validated simulation results enable thorough comprehension of process-related pore formation based on the interaction between keyhole, melt pool and resulting flow field. The findings show that pore formation is driven by four different mechanisms: bulging, spiking, upwelling waves at the keyhole rear wall and melt pool ejections. The synergy of high-speed synchrotron X-ray imaging and multi-physics modeling provides a fundamental understanding of the chronological sequence of events leading to process-related pore formation during laser beam welding of copper.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"204 ","pages":"Article 104224"},"PeriodicalIF":14.0,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142663709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A distinctive material removal mechanism in the diamond grinding of (0001)-oriented single crystal gallium nitride and its implications in substrate manufacturing of brittle materials","authors":"Yueqin Wu ,&nbsp;Qijian Rao ,&nbsp;Zhiyuan Qin ,&nbsp;Shuiping Tan ,&nbsp;Guoqin Huang ,&nbsp;Hui Huang ,&nbsp;Xipeng Xu ,&nbsp;Han Huang","doi":"10.1016/j.ijmachtools.2024.104222","DOIUrl":"10.1016/j.ijmachtools.2024.104222","url":null,"abstract":"<div><div>Single crystal gallium nitride (GaN) substrates are highly demanded for fabricating advanced optoelectronic devices. It is thus essential to develop high efficiency machining technologies for this difficult-to-machine material, which in turn necessitates a thorough understanding of its deformation mechanism. In this study, the deformation and removal characteristics of (0001)-oriented single crystal GaN involved in diamond grinding were systematically investigated. The material removal exhibited a brittle mode when using relatively coarse diamond abrasives of 2000 in mesh size, while ductile removal was achieved when diamond abrasives of 6000 in mesh size were utilized. A novel peeling phenomenon was observed along (0001) lattice plane (c-plane) in the coarse grinding, as the crystal has a hexagonal crystal structure with c-planes serving as the preferable slip/cracking planes. Peeling observed in material removal agrees well with the findings that lateral planar defects were prone to initiate in nanoscratching in comparison to nanoindentation in the ductile regime, indicating that the effect of tangential grinding force is significant. The application of Molecular dynamics (MD) simulations, employing smaller indentation/scratching models, provided additional confirmation of the crucial role played by lateral force in initiating planar defects on c-planes. Furthermore, larger-scale MD scratching models substantiated the occurrence of peeling in the deformation process on c-plane, a finding corroborated by scratching experiments conducted in the brittle regime. Conversely, such peeling is absent on m- and a-planes. Complementary to the simulations, specifically designed grinding experiments were conducted to empirically demonstrate that peeling phenomena were intensified with elevated rotational wheel speeds. This enhancement was attributed to the increased tangential grinding force associated with higher speeds. These findings contribute to a comprehensive understanding of the intricate relationship between rotational wheel speed, tangential grinding force, and the observed peeling mechanisms in the context of single crystal GaN machining.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"203 ","pages":"Article 104222"},"PeriodicalIF":14.0,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening flat-die friction self-pierce riveting joints via manipulating stir zone geometry by tailored rivet structures","authors":"Bowen Zhang ,&nbsp;Yunwu Ma ,&nbsp;Feilong Yu ,&nbsp;Yunpeng Liu ,&nbsp;Entao Zhou ,&nbsp;Zhilei Fan ,&nbsp;Ende Ge ,&nbsp;Yongbing Li ,&nbsp;Zhongqin Lin","doi":"10.1016/j.ijmachtools.2024.104223","DOIUrl":"10.1016/j.ijmachtools.2024.104223","url":null,"abstract":"<div><div>Achieving high-strength joints with flat surfaces is of significant importance for reducing wind resistance and enhancing aesthetic appeal. In this study, a novel flat-die friction self-piercing riveting (flat-die F-SPR) process is proposed. The rivet flaring without die guidance was achieved through the sophisticated design of rivet structures. Three types of rivets with different internal structures were designed to manipulate the material flow and microstructure evolution during the joining process. Based on the method of emergency stop, the load-stroke curves, evolutions of macroscopic morphology, and microstructure of the joints made with different rivets were investigated. A novel mechanism for solid-state bonding of joints was proposed to elucidate the generation and evolution of fine grain regions. The results indicate when downward pressure is applied to the material inside the rivet cavity, a central stirring zone appears. By using a rivet with an annular boss structure, the base material flows continuously into the stirring zone and piled up in the rivet cavity, forming a unique conical-shaped fine grain zone. Finally, a comprehensive assessment of the strength of different types of joints and the transition of the fracture modes were conducted based on different lower sheet thicknesses. The joints of Rivet_B and Rivet_C demonstrate 11.1 % and 6.9 % strength enhancement compared with the joint of Rivet_A, respectively. Two strategies for enhancing the strength of solid-state bonding are proposed, which offers insights for the optimizations of rivet structures.</div></div>","PeriodicalId":14011,"journal":{"name":"International Journal of Machine Tools & Manufacture","volume":"203 ","pages":"Article 104223"},"PeriodicalIF":14.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}