International Journal of Fatigue最新文献

{"title":"Near-threshold fatigue resistance of micrometer-grained steel welds: mechanisms and modeling","authors":"Quan-Heng Yao,&nbsp;Rong Chen,&nbsp;Wen-Qing Lu,&nbsp;Xu-Yang Mo,&nbsp;Ming-Liang Zhu,&nbsp;Fu-Zhen Xuan","doi":"10.1016/j.ijfatigue.2026.109494","DOIUrl":"10.1016/j.ijfatigue.2026.109494","url":null,"abstract":"<div><div>Materials with coarse grains are believed to have higher fatigue threshold with respect to damage tolerance design, in such a context, the mechanisms for fine grains governing fatigue crack propagation are not clear. In this study, the near-threshold fatigue crack propagation behavior of L907A steel welded joints with micrometer-size grains (∼2.5 μm) was investigated, and the associated damage mechanisms near crack-tip were analyzed. It was found that fine grains tended to have lower transition rate down to the near-threshold regime due to the interaction of cyclic plasticity and microstructures, which promoted the formation of nanovoids, nanograins, and amorphization near crack-tip. A modified Zhu-Xuan model was established by taking into account the local microhardness and stress ratios. These findings underscore the importance of grain size engineering in enhancing fatigue resistance and show promise for streamlining the fatigue threshold testing process, thereby reducing associated time and costs.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109494"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure, texture and fatigue performance of friction stir welded dissimilar magnesium alloy joints","authors":"M. Niewczas ,&nbsp;F.G. Basmaji ,&nbsp;A. Kula","doi":"10.1016/j.ijfatigue.2025.109450","DOIUrl":"10.1016/j.ijfatigue.2025.109450","url":null,"abstract":"<div><div>The stress-controlled fatigue of dissimilar friction stir welded AZ80/AZ61 and AZ80/AZ31 magnesium alloy joints was studied. Fatigue testing targeting the critical stir zone — base metal interface revealed endurance limits of 90 MPa for AZ80/AZ61 welds and 70 MPa for AZ80/AZ31 welds. Within the range 60–90 mm/min, welding speed did not affect the endurance limits, though lower speeds produced more homogeneous microstructures and reduced data scatter in AZ80/AZ61 joints. The superior fatigue resistance of AZ80/AZ61 welds is attributed to their stronger and more plastically uniform microstructure, which supports higher stress levels and sustains more cycles before crack nucleation. Cyclic stress–strain analysis shows that AZ80/AZ31 joints exhibit higher hardening rates under cyclic loading compared to AZ80/AZ61 joints, however, both joint types demonstrate significantly reduced hardening compared to monotonic tensile deformation. This behaviour is attributed to low plastic strains during cycling, texture effects inhibiting basal slip, and reversible twinning–detwinning mechanisms. Electron backscatter diffraction analysis revealed substantial texture evolution in the stir zone (SZ), thermomechanically affected (TMAZ) and heat-affected zones (HAZ), with mechanical twinning contributing to grain refinement and mechanical anisotropy. Transmission electron microscopy revealed a complex fatigue dislocation microstructure characterized by networks of basal and non-basal dislocations, with fine dislocation loops and debris present at all stress amplitudes. The density of these defects increased systematically with stress amplitude, providing insight into the cyclic deformation mechanisms governing fatigue life.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"207 ","pages":"Article 109450"},"PeriodicalIF":6.8,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data driven topology optimization of AM parts accounting for process-affected fatigue performance: Application to automotive and aerospace components","authors":"Alessio Centola ,&nbsp;Alberto Ciampaglia ,&nbsp;Carlo Boursier Niutta ,&nbsp;Filippo Berto ,&nbsp;Davide Salvatore Paolino ,&nbsp;Andrea Tridello","doi":"10.1016/j.ijfatigue.2026.109481","DOIUrl":"10.1016/j.ijfatigue.2026.109481","url":null,"abstract":"<div><div>The present paper presents two novel data-driven topology optimization (TO) procedures to design lighter additively manufactured (AM) fatigue resistant components. The first TO method is driven by a probabilistic machine learning (ML) algorithm based on a Bayesian Neural Network (BNN), trained on fatigue data from the literature to assess probabilistic stress-life (PSN) curves. These curves are used to predict the allowable design stress for TO and are predicted directly from AM process parameters, the risk volume, and thermal and surface treatments. The second TO design procedure is instead driven by another BNN, trained to predict the maximum critical defect size from the process parameters. The TO limit stress is computed from the predicted critical defect and the threshold stress intensity factor <em>K_th</em>. After the TO, the critical stress intensity factor <em>K_I</em> in the component is computed and compared against <em>K_th</em>, to assess the effectiveness of this design procedure. These two frameworks are applied to the design of an SS316L automotive suspension lower control arm and a Ti6Al4V aerospace bracket, respectively. With the following framework, the limit stress calculation does not require specifically designed experimental campaigns and prototyping, as previously sparse experimental knowledge can be embedded in a powerful design tool, which allows for preventing fatigue failures, while accounting directly for the influence of the AM process parameters.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109481"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fully-lamellar equiaxed structure mediated excellent high-temperature fatigue crack growth resistance of Ti-48Al-2Cr-2Nb alloy fabricated via twin-wire directed energy deposition-arc process","authors":"Danqi Zhang ,&nbsp;Chen Shen ,&nbsp;Lin Wang ,&nbsp;Wenlu Zhou ,&nbsp;Ting Zhang ,&nbsp;Ying Li ,&nbsp;Yuelong Zhang ,&nbsp;Fang Li ,&nbsp;Jianwen Xin ,&nbsp;Kanglong Wu ,&nbsp;Gang Ruan ,&nbsp;Xueming Hua","doi":"10.1016/j.ijfatigue.2026.109488","DOIUrl":"10.1016/j.ijfatigue.2026.109488","url":null,"abstract":"<div><div>As a critical milestone of twin-wire directed energy deposition-arc (TW-DED-arc) technology, we present the first report on the excellent fatigue crack growth (FCG) performance of a Ti–48Al–2Cr–2Nb (TiAl-4822) alloy with a refined fully-lamellar microstructure. FCG tests conducted on standard compact tension specimens from two orthogonal directions under cyclic loading at 650 °C (R = 0.1) demonstrated a high fatigue threshold (∼8.0 MPa·m^1/2) and low crack propagation rates compared to conventionally manufactured counterparts. The isotropic microstructure rendered crack resistance insensitive to deposition direction. In-situ tensile analysis under electron back scattered diffraction revealed that the enhanced performance originates from refined lamellar spacing, which promoted super-dislocation (SD) activity. Tortuous crack paths formed by mortise–tenon interlocks in inter-lamellar crack and zigzag <em>trans</em>-lamellar cracking, which effectively deflected cracks and dissipate energy. Furthermore, high volume fraction of γ-phase (89.4%) with low stacking fault energy facilitated dislocation dissociation and deformation twinning (DT). These mechanisms collectively enhanced stress relaxation through twin interactions and SD immobilization, significantly improving crack resistance. This study not only reports a previously undocumented property profile but also underscores the technological potential of TW-DED-arc for manufacturing high-performance titanium aluminide components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109488"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Slow fatigue crack growth induced microstructure evolution far beyond the crack tip plastic zone in nickle-based superalloy","authors":"Jiafen Cao ,&nbsp;Mengqi Gu ,&nbsp;Wanlin Guo","doi":"10.1016/j.ijfatigue.2025.109430","DOIUrl":"10.1016/j.ijfatigue.2025.109430","url":null,"abstract":"<div><div>It is widely recognized that the near-threshold slow fatigue crack growth (FCG) in metals is sensitive to their microstructures and the damage zone well within the crack tip plastic zone is the root form FCG. Here we find that near-threshold slow FCG can induce evolution of cyclic microplastic deformation which can significantly change the microstructures in a much larger region than the macroscopic crack tip plastic zone evaluated by classic continuum fracture mechanics theory in compact tension specimens of a Ni-based superalloy at both low and high stress ratios under ambient conditions. Detailed analyses utilizing electron backscatter diffraction and scanning electron microscopy examination reveal that, at low stress ratio of 0.05, near-threshold FCG induces evolution in microstructures through twinning and exhibited hysteresis. While microstructure evolution at high stress ratio of 0.7 is dominated by lattice torsion resulting from dislocation pile-up, without hysteresis. This shows that irreversible cyclic microplastic deformation can induce microstructure changes far outside the macroscopic crack tip plastic zone where the cyclic stress is far below the yield strength of material. The results fundamentally challenge the conventional conception that damage accumulation only occurs within the macroscopic plastic zone, deepen our understanding of why fatigue can occur well below the traditional fatigue limit and FCG continues below the “threshold value”, guiding our design for long life structures.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109430"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145731768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Process gas influence on Very-High-Cycle fatigue response of Inconel 718 fabricated by laser powder bed fusion","authors":"Ali Rauf ,&nbsp;Indrajit Nandi ,&nbsp;Kim Vanmeensel ,&nbsp;Reza Talemi","doi":"10.1016/j.ijfatigue.2025.109460","DOIUrl":"10.1016/j.ijfatigue.2025.109460","url":null,"abstract":"<div><div>Inconel 718 (IN-718) is a precipitation-strengthened nickel-based superalloy that is widely explored for its applicability in fatigue-critical applications when fabricated using additive manufacturing (AM) at an industrial scale. Among the various factors influencing its performance, the choice of shielding gas during laser powder bed fusion (L-PBF) plays a crucial yet often overlooked role in determining the material’s microstructure and mechanical behaviour. This study investigates the critical influence of shielding gases like argon and nitrogen on the microstructure, defect distribution and the very high cycle fatigue (VHCF) durability of heat-treated L-PBF fabricated IN-718. Defect quantification was undertaken using a combination of optical microscopy, Archimedes density measurements, X-ray computed tomography (XCT), revealing higher defect contents in samples processed under nitrogen shielding. Microstructural analysis through scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and energy-dispersive X-ray spectroscopy (EDS) revealed pronounced variations in grain morphology and inclusion content between the two gas environments. VHCF tests were performed under fully reversed, uniaxial, stress-controlled loading at 20 kHz using dog-bone specimens with larger risk volumes to capture a conservative fatigue life assessment. Fatigue life distributions were analysed using a Weibull accelerated failure time model, revealing similar median lives but narrower scatter for argon-shielded specimens. Fractographic analysis revealed distinct crack-initiation mechanisms, microstructure driven initiation in argon-shielded specimens leaving facets at initiation sites versus defect-assisted initiation often involving inclusions along with pores and lack-of-fusion (LOF) defects in nitrogen-shielded counterparts. Although nitrogen shielding produced a refined microstructure, the elevated porosity and inclusion density-controlled crack initiation and degraded fatigue performance.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109460"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting the whole-life stress amplitude evolution of high-Mn TWIP steel under complex loading conditions using fatigue failure criteria and machine learning","authors":"Di Song ,&nbsp;Jinze Pei ,&nbsp;Ye Xiao ,&nbsp;Ronghai Wu ,&nbsp;Heng Li","doi":"10.1016/j.ijfatigue.2025.109449","DOIUrl":"10.1016/j.ijfatigue.2025.109449","url":null,"abstract":"<div><div>Previous research on fatigue performance has primarily focused on fatigue life, with limited emphasis on the evolution of stress amplitude. However, stress amplitude is a critical parameter in strain-controlled fatigue failure analysis. The interaction of deformation mechanisms during cyclic loading complicates the evolution of stress amplitude, and this challenge is further amplified when considering the applicability of models across diverse loading conditions. This study employs both failure criteria-based and machine learning approaches to develop predictive models for the entire fatigue life stress amplitude evolution under varying loading orientations, pre-strains, temperatures, and strain amplitudes. The failure criteria-based model introduces a novel combined prediction framework of fatigue life and stress amplitude, enabling the prediction of four representative stress amplitudes: initial, maximum, half-life, and failure. The fatigue life prediction achieves an accuracy of 96.1 % within a 2 × error band, while stress amplitude predictions attain 96.4 % within a 1.2 × error band. The machine learning model, based on symbolic regression, utilizes these four amplitudes as training data to derive an interpretable formula for the entire evolution curve, achieving 99.7 % data within the 1.2 × error band. The overall curve exhibits a high <em>R</em>² of 0.95 and a mean absolute percentage error (MAPE) of 1.87 %, demonstrating robust predictive capability across diverse conditions.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109449"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on fatigue crack growth characteristics and microscopic damage evolution of ER8 wheel steel with different microstructures","authors":"Yuqi Qiao ,&nbsp;Xiaohui Shi ,&nbsp;Fengfeng Huo ,&nbsp;Minhao Li ,&nbsp;Junwei Qiao","doi":"10.1016/j.ijfatigue.2025.109444","DOIUrl":"10.1016/j.ijfatigue.2025.109444","url":null,"abstract":"<div><div>In the present study, the fatigue crack growth characteristics of ER8 wheel steel were examined. Five billets with different microstructures were prepared by the hot working process. The correlation between fatigue crack growth rate (d<em>a</em>/d<em>N</em>) and stress intensity factor range (Δ<em>K</em>) was derived based on stress-controlled fatigue experiments. Fatigue crack growth paths were analyzed with the assistance of electron backscatter diffraction (EBSD) technology. EBSD analysis revealed that cracks were deflected when encountering high-angle grain boundaries and tend to propagate along low-energy paths, with low-angle grain boundaries being such paths. Finally, based on the tensile property parameters of the materials, two prediction models were established to assess the effect of microstructural morphologies on the fatigue crack growth rate.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109444"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145796194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical defect-driven fatigue evolution mechanism and life prediction of Ti6Al4V part built by laser powder bed fusion","authors":"Jiasen Gu ,&nbsp;Deqiao Xie ,&nbsp;Xuwen Gu ,&nbsp;Shuang Liu ,&nbsp;Kai Zhou ,&nbsp;Chen Jiao ,&nbsp;Rong Jiang ,&nbsp;Xinfeng Lv ,&nbsp;Juan Hu ,&nbsp;Zongjun Tian ,&nbsp;Dongsheng Wang ,&nbsp;Lida Shen","doi":"10.1016/j.ijfatigue.2025.109476","DOIUrl":"10.1016/j.ijfatigue.2025.109476","url":null,"abstract":"<div><div>Fatigue life prediction of laser powder bed fusion (LPBF) components remains challenging because critical defects cannot be reliably identified before service, resulting in large scatter and limited applicability of existing methods. In this study, an integrated framework combining quasi <em>in-situ</em> X-ray computed tomography (XCT), finite element method (FEM), and machine learning (ML) was developed to rapidly screen critical defects and predict fatigue life prior to loading. The results revealed the early-stage evolution of critical defects during crack initiation, and a Murakami-Basquin model was established to quantitatively link defect features with fatigue life. Moreover, the FEM-driven ML approach achieved high-accuracy life prediction within a 1.5× error band, with <span><math><msub><mi>σ</mi><mrow><mi>FEM</mi></mrow></msub></math></span> identified as the dominant factor, followed by defect depth (<span><math><mi>h</mi></math></span>) and <span><math><msqrt><mrow><mi>area</mi></mrow></msqrt></math></span>, in agreement with classical fatigue criteria. Demonstrated with Ti6Al4V, this work establishes a critical-defect-driven pathway for fatigue life prediction, providing a broadly applicable methodology for defect-sensitive design and life assessment of LPBF components.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109476"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase boundary and defect dependent high cycle fatigue behavior in AlCoCrFeNi2.1 eutectic high-entropy alloy","authors":"Xiaochuan Yang ,&nbsp;Tianxin Li ,&nbsp;Jiang Yang ,&nbsp;Mingpan Wan ,&nbsp;Zhong Zhang ,&nbsp;Chaowen Huang","doi":"10.1016/j.ijfatigue.2025.109462","DOIUrl":"10.1016/j.ijfatigue.2025.109462","url":null,"abstract":"<div><div>The AlCoCrFeNi_2.1 (Ni21) eutectic high-entropy alloy (EHEA) exhibits a dual-phase heterogeneous microstructure that contributes to its high strength and ductility. However, its high cycle fatigue (HCF) damage mechanisms remain insufficiently understood and restrict its practical application. In this study, the HCF behavior of the as-cast Ni21 alloy was systematically investigated. The alloy exhibits a fatigue strength of approximately 297 MPa (<em>σ_-1</em> (10⁷)), corresponding to a fatigue ratio (<em>σ_-1</em> (10⁷)/<em>YS</em>) of 0.512. Under cyclic loading, dislocations are preferentially activated in the face-centered cubic (FCC) phase and accumulate at phase boundaries (PBs), where they induce stress concentration and trigger fatigue microcrack initiation. Meanwhile, nano-precipitates within the ordered body-centered cubic (B2) phase effectively hinder dislocations transmission across PBs, thereby enhancing resistance to fatigue crack initiation. The combined contribution of the dual-phase microstructure and nano- precipitates plays a critical role in extending fatigue life. Furthermore, fatigue crack propagation is most effectively suppressed when the crack growth direction intersects PBs at angles between 40° and 70°. Considerable scatter in the HCF data is observed, primarily resulting from casting defects such as blowholes. Overall, these findings highlight that further improvements in the HCF performance of Ni21 alloy will require improved casting quality or appropriate thermo-mechanical treatments.</div></div>","PeriodicalId":14112,"journal":{"name":"International Journal of Fatigue","volume":"206 ","pages":"Article 109462"},"PeriodicalIF":6.8,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145845099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}