{"title":"Anomalous anisotropy in an additively manufactured solid-solution-strengthened superalloy from room to elevated temperatures","authors":"Zhenhua Zhang, Zixu Guo, Quanquan Han, Daijun Hu, Shiwei Wu, Haiyang Fan, Erlei Li, Ming Li, Yilun Xu, Shoufeng Yang, Chuanzhen Huang, Wentao Yan","doi":"10.1016/j.ijplas.2025.104409","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104409","url":null,"abstract":"Metal additive manufacturing (AM) produces unique grain morphologies owing to the high cooling rates and large temperature gradients, which potentially lead to unexpected mechanical anisotropy. In this study, we unveil an anomalous anisotropic behaviour in a solid-solution-strengthened superalloy with periodic columnar-to-crescent grains fabricated by laser powder bed fusion (LPBF). Specifically, as-built (AB) specimens show higher strength perpendicular to the build direction (BD) than that parallel to the BD at room temperature (RT), while the opposite trend occurs at the elevated temperature (ET, 900°C). Besides, the heat treatment eliminates the anisotropy of strength at both RT and ET. A dislocation-based damage-coupled crystal plasticity finite element (CPFE) model with strain gradients is utilized to understand the origin of the above anomalous anisotropy. It is found that the transition of anisotropy from RT to ET is attributed to the temperature-dependent dislocation annihilation combined with initial dislocations in AB state. In contrast to the heat-treated specimens without anisotropy, the LPBF-induced residual deformation primarily contributes to the anisotropy at RT, whereas the initial dislocations dominate the anomalous anisotropy at ETs for AB specimens. The CPFE model reveals the threshold temperature to be 600°C for the occurrence of anomalous anisotropy, which is experimentally validated. This study presents a comprehensive understanding into temperature-dependent anisotropy of AM superalloys, and in turn guides the regulation of anisotropy by tuning microstructures.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"17 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144547527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hydrogen-induced twin boundary passivation in multi-principal element alloy: a micropillar compression study","authors":"Qi Zhu, Siyuan Wei, Qian Zhang, Yakai Zhao, Upadrasta Ramamurty, Yang Lu, Huajian Gao","doi":"10.1016/j.ijplas.2025.104411","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104411","url":null,"abstract":"The ingress of nascent hydrogen into alloys can significantly alter their mechanical behaviors, leading to the well-known phenomenon of hydrogen embrittlement (HE) and catastrophic failure of structural components in service. As an emerging class of materials, some face-centered cubic multi-principal element alloys (MPEAs) exhibit unique resistance to HE, with the frequent presence of coherent twin boundaries (TBs) widely acknowledged as a contributing factor. However, the underlying mechanisms of TB-enhanced HE resistance remain under debate. Here, we selectively activate orientation-dependent TB-dislocation interactions by compressing [<span><math><mrow is=\"true\"><mover accent=\"true\" is=\"true\"><mn is=\"true\">1</mn><mo is=\"true\">¯</mo></mover><mover accent=\"true\" is=\"true\"><mn is=\"true\">1</mn><mo is=\"true\">¯</mo></mover></mrow></math></span>2]- and [0<span><math><mover accent=\"true\" is=\"true\"><mn is=\"true\">1</mn><mo is=\"true\">¯</mo></mover></math></span>1]-oriented CoCrFeNi MPEA micropillars containing an individual TB. This approach provides a benchmark for elucidating the hydrogen-induced deformation behaviors. An enhanced yield strength and orientation-dependent strain hardening are observed, attributed to hydrogen-induced TB passivation against slip transmission, with minimal impact on intragranular dislocation activities. Microstructural analysis reveals dislocation impediments at TBs and dislocation entanglements within the grains, confirming the hydrogen-induced TB passivation mechanism. These findings provide critical insights into the role of hydrogen in TB-facilitated plastic deformation and offer guidance for future studies aiming to comprehensively understand the HE resistance of MPEAs.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"12 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiahao Li, Xinkai Ma, Jun Zhou, Chuanlong Xu, Peidong Li, Xiaobao Tian, Qingyuan Wang, Haidong Fan
{"title":"Strain-bearing capacity and strain hardening awakened by inter-zone constraint in twin-structured Al0.1CoCrFeNi alloy","authors":"Jiahao Li, Xinkai Ma, Jun Zhou, Chuanlong Xu, Peidong Li, Xiaobao Tian, Qingyuan Wang, Haidong Fan","doi":"10.1016/j.ijplas.2025.104410","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104410","url":null,"abstract":"Twin networks endow structural metallic materials with unprecedented mechanical properties. However, the understanding of how to utilize the maximum mechanical potential of twin structures remains limited, thus hindering the full performance of twin networks. In this work, the twin networks are embedded within fine grains (FGs) in Al<sub>0.1</sub>CoCrFeNi alloy to awaken the strain-bearing capacity and strain hardening of twin networks. The experimental results show that the inter‑zone deformation incompatibility generates strong FG constraints that suppress early strain localization in the twin networks, raising the uniform elongation from 3 ± 0.5% to 27 ± 3%. Molecular dynamics simulations further verify that the intrinsic deformation mechanism of twin networks changes from necklace-like dislocations to hairpin-like dislocations under inter‑zone constraints. The strain hardening originates not only from the hetero-deformation induced strengthening and hardening, but also from the awakened strain-bearing capacity of twin networks, where the twin networks contribute ∼15% hardening. These findings highlight the potential for enhancing the strengthening and hardening effects of twin networks by introducing extra constraint effect.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"45 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144533677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Creep deformation of unidirectional metal matrix composites: modeling and experimental observations","authors":"Xu Kong, Yumin Wang, Rui Yang","doi":"10.1016/j.ijplas.2025.104407","DOIUrl":"10.1016/j.ijplas.2025.104407","url":null,"abstract":"<div><div>The creep response of elastic fiber-reinforced metal matrix composites is modeled by establishing governing equations that link the composite's behavior under creep tests to that of the unreinforced creeping matrix in the stress relaxation test. These findings diverge from widely accepted models, which are well-acknowledged on the <em>priori</em> assumption of extending the steady-state creep method from constant stress to decreasing stress conditions. The unreachability of the steady-state creep of the creeping matrix with elastic reinforcements is demonstrated, as continuous stress transfer occurs from the creeping matrix to the elastic fibers. Experimental validation through stress relaxation tests reveals significant discrepancies, including underestimation in the short term and overestimation in the long term, driven by altered stress evolution paths for the creeping matrix. In this work, the relationships of governing equations among stress relaxation tests of unreinforced matrices, creep tests of composites and stress relaxation tests of composites are established, emphasizing the condition of the creeping matrix under decreasing stress. The difference in the effect of broken fibers on the strain increase between localized strain within the stress recovery distance and averaged strain over the extensometer gauge length is discussed. An experimental validation method is proposed and conducted by examining the elastic modulus variation of the composite in the loading and unloading stages during repeated creep tests.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"192 ","pages":"Article 104407"},"PeriodicalIF":9.4,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144520948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanism and modelling of the electroplastic effect in titanium alloy: From the perspective of dislocation slip","authors":"H.T. Niu , P.F. Gao , H.W. Li , M. Zhan","doi":"10.1016/j.ijplas.2025.104405","DOIUrl":"10.1016/j.ijplas.2025.104405","url":null,"abstract":"<div><div>Electrically assisted (EA) forming technology has gained attention for manufacturing the difficult-to-form components of titanium alloy. However, the mechanism of the electroplastic (EP) effect on deformation behaviors remains unclear and the EP effect-coupled constitutive models are scarce, which hinders application of electrical current. In this study, the mechanism of the EP effect on deformation behavior was investigated from pinning, depinning, drag and release stages of dislocation slip. It is found that the thermal EP effect presented in pinning, depinning and release stages, whose mechanism was the same as that in thermally-assisted deformation. In contrast, the athermal EP effect enhanced dislocation pinning and depinning behaviors through promoting solute diffusion to dislocation line and generation of the electrical free energy at pinning points, respectively. While, the athermal EP effect didn’t influence the release stage. Then, a physically based EA constitutive model was established. The thermal effect was modelled using thermal activation theory for pinning and depinning stages and Seeger’s relation for release stage. The athermal effect on pinning stage was modelled by evaluating solute concentration near mobile dislocations based on electromigration theory and metallic bond dissolution theory. Besides, the athermal effect on depinning stage was modelled by calculating the electrical free energy generated at pinning points based on electrical free energy theory. The model provided good predictive ability and wide application range. Based on the model, the contributions of the thermal and athermal EP effects to flow stress were quantified under various EA deformation conditions.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"192 ","pages":"Article 104405"},"PeriodicalIF":9.4,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peibo Li , Guoqiang Luo , Jianian Hu , Ruizhi Zhang , Di Ouyang , Yu Yang , Yi Sun , Qiang Shen
{"title":"Microstructure evolution and spall behavior of 2024Al alloy under ramp wave loading","authors":"Peibo Li , Guoqiang Luo , Jianian Hu , Ruizhi Zhang , Di Ouyang , Yu Yang , Yi Sun , Qiang Shen","doi":"10.1016/j.ijplas.2025.104399","DOIUrl":"10.1016/j.ijplas.2025.104399","url":null,"abstract":"<div><div>Understanding the strain rate-dependent response of materials is essential for optimizing their design and predicting service life. In this study, both ramp wave loading (10<sup>4</sup>–10<sup>5</sup> s⁻¹) and square wave loading (10<sup>6</sup> s⁻¹) were achieved by controlling the projectile structure in plate impact experiments. This work particularly focuses on spall strength, precipitation behavior and damage evolution in 2024Al alloy under ramp wave loading. The results reveal that ramp loading mitigates thermal softening through gradual stress variation and reduces dislocation–atomic interactions due to its extended rise time. Compared with square wave loading, the continuous strain under ramp loading promotes vacancy generation, facilitating abnormal precipitation. These factors collectively contribute to enhanced spall strength. The spallation mechanism is dominated by dislocation–grain boundary interactions, with void nucleation and growth primarily occurring at grain boundaries. The formation of double spall surfaces is attributed to tensile stress concentrations generated by shock wave reflections at the initial spall surface. This study emphasizes the influence of shock waves on the structure and damage behavior of the 2024Al alloy.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"191 ","pages":"Article 104399"},"PeriodicalIF":9.4,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144488438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xu Yang, Gang Qin, Li Feng, Hao Ren, Yao Chen, Qi Wang, Ruirun Chen
{"title":"Development of high-strength and high-ductility high-entropy alloys via directional solidification: A multifaceted strengthening approach","authors":"Xu Yang, Gang Qin, Li Feng, Hao Ren, Yao Chen, Qi Wang, Ruirun Chen","doi":"10.1016/j.ijplas.2025.104403","DOIUrl":"10.1016/j.ijplas.2025.104403","url":null,"abstract":"<div><div>High-strength and high-ductility alloys are crucial for advanced engineering applications; however, achieving a balanced combination of these two properties remains a significant challenge. Here, we successfully developed an alloy with exceptional mechanical properties through microstructural design and processing optimization. By employing directional solidification, we fabricated an Al<sub>1.25</sub>CoCrFeNi<sub>2.8</sub>Mo<sub>0.2</sub> dual-phase high-entropy alloy (HEA) that exhibits a distinctive microstructure, which significantly enhances both strength and ductility. The alloy demonstrates superior mechanical performance, with a yield strength of 505 MPa, ultimate tensile strength of 1166 MPa, and uniform elongation of 19 %. Compared with the conventional as-cast HEA, the elongation is increased by 46 %, and the tensile strength is increased by 5 %. The enhanced properties are attributed to a synergistic combination of solid solution strengthening, phase interface strengthening, and precipitation hardening mechanisms. Detailed microstructural analysis reveals that hierarchical stacking fault networks in the face-centered cubic phase facilitate enhanced work hardening. Concurrently, B2-ordered nanoparticles acted as potent obstacles to dislocation motion, resulting in a significant enhancement of the strength. Additionally, the unidirectional lamellar microstructure improves fracture toughness by inhibiting crack propagation. This study underscores the potential of combining advanced metallurgical design with processing techniques to produce high-strength, ductile metallic materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"191 ","pages":"Article 104403"},"PeriodicalIF":9.4,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144479575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H.Y. Li , Z.L. Ma , Z.Q. Xu , S.K. Guo , X.Y. Li , G.D. Zhang , X.W. Cheng
{"title":"Achieving synergistic strength-ductility in a novel refractory high-entropy alloy from room to high temperatures through nano-silicide precipitation-mediated dislocation dynamics","authors":"H.Y. Li , Z.L. Ma , Z.Q. Xu , S.K. Guo , X.Y. Li , G.D. Zhang , X.W. Cheng","doi":"10.1016/j.ijplas.2025.104402","DOIUrl":"10.1016/j.ijplas.2025.104402","url":null,"abstract":"<div><div>Refractory high-entropy alloys (RHEAs) face critical challenges in reconciling room-temperature ductility with high-temperature strength retention and microstructural stability for extreme-condition applications. Here, we develop a novel non-equimolar and low-density (V<sub>30</sub>Nb<sub>40</sub>Ti<sub>20</sub>Ta<sub>10</sub>)<sub>99</sub>Si<sub>1</sub> RHEA (7.91 g/cm<sup>3</sup>) that achieves unprecedented synergy of ambient deformability and elevated-temperature performance via nano-silicide precipitation engineering and dislocation dynamics optimization. The alloy achieves an exceptional strength-ductility synergy at room temperature (yield strength: 958 MPa, fracture strain: 33.1 %, uniform tensile elongation: 15.7 %) via nano-silicide-mediated cross-slip, multi-planar slip, and hierarchical dislocation substructure evolution. At 1000 °C, the alloy retains 258 MPa yield strength with 76 % elongation, outperforming conventional wrought superalloys. Multiscale analysis reveals that the combined effects of precipitation strengthening and DRX-driven microstructure evolution allow (V<sub>30</sub>Nb<sub>40</sub>Ti<sub>20</sub>Ta<sub>10</sub>)<sub>99</sub>Si<sub>1</sub> to preserve its mechanical integrity under severe thermomechanical environments. Long-term heat exposure (120 h at 1000 °C) proves the alloy's high stability, exhibiting negligible microstructural evolution and >99 % strength retention. The balance of mechanical properties and microstructural stability enables the novel RHEA to stand out among RHEAs. This study offers critical insights into designing RHEAs that achieve a balance of ambient deformability, high-temperature strength, and microstructural stability, thereby enhancing their potential for aerospace and turbine material applications.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"191 ","pages":"Article 104402"},"PeriodicalIF":9.4,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144371050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S.Y. Peng , W. Gong , Y.Z. Tian , Z.J. Gu , Z.Y. Ni , S. Harjo , S. Lu , G.W. Qin , S. Li
{"title":"Strengthening characteristics of CoCrNi alloys with different stacking fault energies","authors":"S.Y. Peng , W. Gong , Y.Z. Tian , Z.J. Gu , Z.Y. Ni , S. Harjo , S. Lu , G.W. Qin , S. Li","doi":"10.1016/j.ijplas.2025.104401","DOIUrl":"10.1016/j.ijplas.2025.104401","url":null,"abstract":"<div><div>Quantifying the contributions of various strengthening mechanisms is essential for manipulating these mechanisms and designing novel alloys. Although CoCrNi alloys demonstrate exceptional mechanical properties, their strengthening characteristics remain to be investigated. In this work, we conducted <em>in situ</em> neutron diffraction tensile tests and characterized deformation microstructures for CoCrNi alloys with different stacking fault energies (SFEs). The dislocation strengthening characteristics and the role of planar faults were systematically investigated. A reduction in SFE restricts cross slip, thereby increasing the dislocation multiplication rate while decreasing the dislocation strengthening coefficient <em>α</em>. Additionally, a lower SFE facilitates the simultaneous activation of dislocations and planar faults, with dislocation strengthening consistently playing a dominant role. This work quantifies reasonable <em>α</em> values for CoCrNi alloys and identifies cross slip as a critical factor potentially influencing <em>α</em> value in face-centered cubic (FCC) alloys.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"191 ","pages":"Article 104401"},"PeriodicalIF":9.4,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144341431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wee King Law , Haoliang Wang , Chenghao Song , Kok-Cheong Wong , Chin Seong Lim , Zhenzhong Sun
{"title":"Influence of microstructural heterogeneity on the plastic strain localisation in selective laser melted 18Ni-300 maraging steel","authors":"Wee King Law , Haoliang Wang , Chenghao Song , Kok-Cheong Wong , Chin Seong Lim , Zhenzhong Sun","doi":"10.1016/j.ijplas.2025.104400","DOIUrl":"10.1016/j.ijplas.2025.104400","url":null,"abstract":"<div><div>Plastic strain localisation in selective laser melted (SLM) 18Ni-300 maraging steel under uniaxial tensile loading was characterised via electron backscatter diffraction (EBSD), in-situ tensile experiments, and digital image correlation under the scanning electron microscope (a methodology known as SEM-DIC). Two sample conditions were investigated, namely the as-built (AB) and solution-aging treatment (SAT) conditions. During plastic deformation, the large quantity of equiaxed grains in the AB sample led to grain boundary strengthening, while the presence of densely distributed Ni-based intermetallics in the SAT sample led to strain hardening. SEM-DIC analysis revealed that plastic strain localisation in AB and SAT samples exhibited significant heterogeneity and was highly localised. Slip was identified as the main deformation mechanism for both AB and SAT samples, and preferentially occurred in grains with increased internal misorientation. Five or more independent slip systems were active in the investigated grains of AB and SAT samples during plastic deformation. The combined kinematics of the active slip systems were reflected in the in-plane deformation behaviour for the investigated grains (i.e. G2 in AB sample and G8 in SAT sample). The findings of the present work would provide fundamental insights into tailoring the material’s microstructure for optimised performance in industrial applications.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"191 ","pages":"Article 104400"},"PeriodicalIF":9.4,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144337565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}