Pub Date : 2025-02-26DOI: 10.1016/j.ijplas.2025.104291
Minghao Hu , Chong Li , Shengyu Zhou , Qianying Guo , Zongqing Ma , Huijun Li , Xingchuan Xia , Yongchang Liu
The intra-granular γ′ phase and inter-granular M23C6 in a polycrystalline Ni3Al-based superalloy are cooperatively controlled through a two-stage-cooling solution treatment. The rapid cooling stage suppresses the coarsening of the γ′ phase, while the subsequent slow cooling stage promotes the precipitation of M23C6. The co-strengthening of intra- and inter-granular particles leads to a longer creep life. Intra-granularly, topologically inverse microstructures are formed, the deformation is dominated by the motion of antiphase boundary coupled superpartials. Inter-granularly, the movement of superdislocations towards the grain boundary is obstructed by the M23C6. Based on these observations, theoretical models are employed to construct the relationship between the creep properties and the micro/sub-structures. The threshold stress against dislocation movement contributed by γ′ phase, the boundary obstacle stress induced by M23C6 and the energy barrier for inter-granular cavity nucleation are calculated for discussion.
{"title":"Cooperatively controlling γ′ phase and M23C6 of a polycrystalline Ni3Al-based superalloy: Microstructure and creep resistance","authors":"Minghao Hu , Chong Li , Shengyu Zhou , Qianying Guo , Zongqing Ma , Huijun Li , Xingchuan Xia , Yongchang Liu","doi":"10.1016/j.ijplas.2025.104291","DOIUrl":"10.1016/j.ijplas.2025.104291","url":null,"abstract":"<div><div>The intra-granular γ′ phase and inter-granular M<sub>23</sub>C<sub>6</sub> in a polycrystalline Ni<sub>3</sub>Al-based superalloy are cooperatively controlled through a two-stage-cooling solution treatment. The rapid cooling stage suppresses the coarsening of the γ′ phase, while the subsequent slow cooling stage promotes the precipitation of M<sub>23</sub>C<sub>6</sub>. The co-strengthening of intra- and inter-granular particles leads to a longer creep life. Intra-granularly, topologically inverse microstructures are formed, the deformation is dominated by the motion of antiphase boundary coupled superpartials. Inter-granularly, the movement of superdislocations towards the grain boundary is obstructed by the M<sub>23</sub>C<sub>6</sub>. Based on these observations, theoretical models are employed to construct the relationship between the creep properties and the micro/sub-structures. The threshold stress against dislocation movement contributed by γ′ phase, the boundary obstacle stress induced by M<sub>23</sub>C<sub>6</sub> and the energy barrier for inter-granular cavity nucleation are calculated for discussion.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104291"},"PeriodicalIF":9.4,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496029","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}
Pub Date : 2025-02-24DOI: 10.1016/j.ijplas.2025.104284
Damien Texier , Julien Genée , Vincent Velay , Antonio Castro Moreno , Daniel Monceau , Eric Andrieu
Surface effects were investigated using ultrathin specimens with thicknesses in the order of the grain size of the material. The candidate material was a polycrystalline Ni-based superalloy (Alloy 718) purposely heat treated to document both the effects of the grain size and the metallurgical state, , solid solution and precipitation hardened state, on the polycrystalline-to-multicrystalline behavior. Ultrathin tensile specimens were prepared with a dedicated technique to obtain specimens with thicknesses ranging between 20 and 550 , then tensile tested at room temperature. The polycrystalline-to-multicrystalline transition (PMT) was found to depend on the material grain size relative to the specimen thickness and to impair severely the tensile strength of the material. The yield strength, ultimate tensile strength (maximal stress on the stress–strain curve) and strain-to-failure severely dropped for specimens thinner than approximately two times the grain size of the material regardless of the metallurgical state. Such a decrease in tensile properties is mainly attributed to free-surface effects acting as an escape sink of dislocations, thus leading to a significant decrease of the primary dislocations density within the surface grains in comparison with the core grains. Interestingly, difference in work-hardening behavior with size reduction was found between both precipitation states, the solid solution state being more sensitive with the size reduction. The decrease in tensile properties was not found as expected from the commonly reported “thickness/grain size ()” ratio. Therefore, a numerical approach using a modified Berveiller–Zaoui self-consistent model based on a continuum crystal plasticity approach was conducted in the present paper to distinguish microstructural features acting as strengthening (dislocation accumulation) and softening (dislocation escape at the free-surface) features. 3D numerical materials were produced using Voronoi tessellation methods to represent the fraction of “core grains” versus “surface grains”. These fractions were then used as microstructural parameters for the identification of a crystal plasticity model using mean-field homogenization with different populations of grains, , core versus surface features. The present work aimed at distinguishing the mechanical behavior of surface grains from core grains in Alloy 718 Ni-based superalloys using various thicknesses of specimens and different microstructure and metallurgical state variants.
{"title":"Size effects on the plastic behavior of polycrystalline materials: Grain size, precipitation state and free-surface effects","authors":"Damien Texier , Julien Genée , Vincent Velay , Antonio Castro Moreno , Daniel Monceau , Eric Andrieu","doi":"10.1016/j.ijplas.2025.104284","DOIUrl":"10.1016/j.ijplas.2025.104284","url":null,"abstract":"<div><div>Surface effects were investigated using ultrathin specimens with thicknesses in the order of the grain size of the material. The candidate material was a polycrystalline Ni-based superalloy (Alloy 718) purposely heat treated to document both the effects of the grain size and the metallurgical state, <span><math><mrow><mi>i</mi><mo>.</mo><mi>e</mi><mo>.</mo></mrow></math></span>, solid solution and precipitation hardened state, on the polycrystalline-to-multicrystalline behavior. Ultrathin tensile specimens were prepared with a dedicated technique to obtain specimens with thicknesses ranging between 20 and 550 <span><math><mrow><mi>μ</mi><mtext>m</mtext></mrow></math></span>, then tensile tested at room temperature. The polycrystalline-to-multicrystalline transition (PMT) was found to depend on the material grain size relative to the specimen thickness and to impair severely the tensile strength of the material. The yield strength, ultimate tensile strength (maximal stress on the stress–strain curve) and strain-to-failure severely dropped for specimens thinner than approximately two times the grain size of the material regardless of the metallurgical state. Such a decrease in tensile properties is mainly attributed to free-surface effects acting as an escape sink of dislocations, thus leading to a significant decrease of the primary dislocations density within the surface grains in comparison with the core grains. Interestingly, difference in work-hardening behavior with size reduction was found between both precipitation states, the solid solution state being more sensitive with the size reduction. The decrease in tensile properties was not found as expected from the commonly reported “thickness/grain size (<span><math><mrow><mi>t</mi><mo>/</mo><mi>D</mi></mrow></math></span>)” ratio. Therefore, a numerical approach using a modified Berveiller–Zaoui self-consistent model based on a continuum crystal plasticity approach was conducted in the present paper to distinguish microstructural features acting as strengthening (dislocation accumulation) and softening (dislocation escape at the free-surface) features. 3D numerical materials were produced using Voronoi tessellation methods to represent the fraction of “core grains” versus “surface grains”. These fractions were then used as microstructural parameters for the identification of a crystal plasticity model using mean-field homogenization with different populations of grains, <span><math><mrow><mi>i</mi><mo>.</mo><mi>e</mi><mo>.</mo></mrow></math></span>, core versus surface features. The present work aimed at distinguishing the mechanical behavior of surface grains from core grains in Alloy 718 Ni-based superalloys using various thicknesses of specimens and different microstructure and metallurgical state variants.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"188 ","pages":"Article 104284"},"PeriodicalIF":9.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143477593","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}
Pub Date : 2025-02-24DOI: 10.1016/j.ijplas.2025.104289
X.P. Zhang , C.F. Fang , R. Wang , C.J. Li , Y. Zhao , J.T. Feng , W.Y. Li , S.B. Mi , Y.M. Wang
Texture weakening by dynamic recrystallization (DRX) control has been a challenging issue on improving the mechanical performance of wrought Mg alloys. Here we report the attainment of bi-directional DRX in an AZ31-0.9Nd-0.3Y alloy, which accelerated DRX and weakened the basal texture. The nature and content of secondary phase particles in the solidification microstructures were modified by the mixed-addition of rare-earth elements, and a dispersive distribution of Al11RE3 particles located at grain boundaries (GBs) and grain-interior Al2RE particles was achieved in the AZ31-0.9Nd-0.3Y alloy. Compared with the AZ31 and the alloys with sole-element addition, DRX in AZ31-0.9Nd-0.3Y occurred at a smaller critical strain at the same strain rate and extrusion temperature. Upon extrusion, GB bulging, continuous DRX, twin-induced nucleation and particle-stimulated nucleation (PSN) were operative but play a different part in the different stages of deformation. The Al11RE3 and Al2RE particles induced respectively inward and outward growth of DRXed grains at large strains, representing a bi-directional DRX behavior. The twin-induced DRX ceased to occur while the PSN carried by grain-interior particles caused substantial orientation randomness of the DRXed grains. Multiple dislocation slip systems were activated in the particle deformation zones to form dislocation cells, nucleating DRXed grains with a rich variety of orientations in the neighborhood of the particles. The extruded AZ31-0.9Nd-0.3Y alloy exhibited simultaneous improvement of strength and ductility performance.
{"title":"Bi-directional dynamic recrystallization behavior of AZ31 alloy by Al-RE precipitation control","authors":"X.P. Zhang , C.F. Fang , R. Wang , C.J. Li , Y. Zhao , J.T. Feng , W.Y. Li , S.B. Mi , Y.M. Wang","doi":"10.1016/j.ijplas.2025.104289","DOIUrl":"10.1016/j.ijplas.2025.104289","url":null,"abstract":"<div><div>Texture weakening by dynamic recrystallization (DRX) control has been a challenging issue on improving the mechanical performance of wrought Mg alloys. Here we report the attainment of bi-directional DRX in an AZ31-0.9Nd-0.3Y alloy, which accelerated DRX and weakened the basal texture. The nature and content of secondary phase particles in the solidification microstructures were modified by the mixed-addition of rare-earth elements, and a dispersive distribution of Al<sub>11</sub>RE<sub>3</sub> particles located at grain boundaries (GBs) and grain-interior Al<sub>2</sub>RE particles was achieved in the AZ31-0.9Nd-0.3Y alloy. Compared with the AZ31 and the alloys with sole-element addition, DRX in AZ31-0.9Nd-0.3Y occurred at a smaller critical strain at the same strain rate and extrusion temperature. Upon extrusion, GB bulging, continuous DRX, twin-induced nucleation and particle-stimulated nucleation (PSN) were operative but play a different part in the different stages of deformation. The Al<sub>11</sub>RE<sub>3</sub> and Al<sub>2</sub>RE particles induced respectively inward and outward growth of DRXed grains at large strains, representing a bi-directional DRX behavior. The twin-induced DRX ceased to occur while the PSN carried by grain-interior particles caused substantial orientation randomness of the DRXed grains. Multiple dislocation slip systems were activated in the particle deformation zones to form dislocation cells, nucleating DRXed grains with a rich variety of orientations in the neighborhood of the particles. The extruded AZ31-0.9Nd-0.3Y alloy exhibited simultaneous improvement of strength and ductility performance.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104289"},"PeriodicalIF":9.4,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143485530","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}
Pub Date : 2025-02-23DOI: 10.1016/j.ijplas.2025.104288
Hang Zhang, Xuanzhe Li, Jinyu Zhang, Suzhi Li, Shaohua Gao, Gang Liu, Jun Sun
Design structural characteristics of interfaces is the key for ultra-strong titanium (Ti) alloys by tuning polymorphic α-precipitates. However, the conventional tri-modal structure, characterized by various interfaces, usually shows large ductility but low yield strength caused by numerous soft α-precipitates. This work focuses on manipulating multiple interfacial structures to endow a newly designed tri-modal Ti-4.9Al-4.4Cr-2.45Mo-1.6Zr alloys with the superior strength-ductility synergy assisted by interstitial solutes, beyond conventional high-strength Ti alloys. Here, an interstitial solute alloying strategy is utilized not only to form hard-yet-deformable α-precipitates, but also to achieve the controllably stepwise α-precipitation sequence to manipulate interfacial structures and thus slip transmission modes in Ti alloys. In particular, the coherent twin boundaries (CTBs) between secondary α-nanolamellae formed via dislocation-interstitial atom interactions can efficiently hinder dislocation motion but promote dislocation transmission in the soft transformed β-matrix. This strategy provides new insights into designing high-performance interstitial solute-tolerant alloys for cost-effective and lightweight applications.
{"title":"Manipulating the interfacial structures in titanium alloys containing interstitial solutes delivers ultra-high strength and ductility","authors":"Hang Zhang, Xuanzhe Li, Jinyu Zhang, Suzhi Li, Shaohua Gao, Gang Liu, Jun Sun","doi":"10.1016/j.ijplas.2025.104288","DOIUrl":"10.1016/j.ijplas.2025.104288","url":null,"abstract":"<div><div>Design structural characteristics of interfaces is the key for ultra-strong titanium (Ti) alloys by tuning polymorphic α-precipitates. However, the conventional tri-modal structure, characterized by various interfaces, usually shows large ductility but low yield strength caused by numerous soft α-precipitates. This work focuses on manipulating multiple interfacial structures to endow a newly designed tri-modal Ti-4.9Al-4.4Cr-2.45Mo-1.6Zr alloys with the superior strength-ductility synergy assisted by interstitial solutes, beyond conventional high-strength Ti alloys. Here, an interstitial solute alloying strategy is utilized not only to form hard-yet-deformable α-precipitates, but also to achieve the controllably stepwise α-precipitation sequence to manipulate interfacial structures and thus slip transmission modes in Ti alloys. In particular, the coherent twin boundaries (CTBs) between secondary α-nanolamellae formed via dislocation-interstitial atom interactions can efficiently hinder dislocation motion but promote dislocation transmission in the soft transformed β-matrix. This strategy provides new insights into designing high-performance interstitial solute-tolerant alloys for cost-effective and lightweight applications.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104288"},"PeriodicalIF":9.4,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473530","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}
Pub Date : 2025-02-22DOI: 10.1016/j.ijplas.2025.104286
Guanghao Guo , Wenqiang Zhang , Bin Zhang , Jiachen Xu , Shuang Chen , Xianjue Ye , Yuefei Zhang , Ze Zhang
In this study, in-situ tensile experiments were conducted on three samples containing different precipitate phases (δ, γ″ and γ′) to investigate the effects of these precipitates on the tensile deformation mechanisms of Alloy 718. Local plastic deformation was characterized by digital image correlation (DIC) and electron back-scatter diffraction (EBSD). The plasticity was analyzed in terms of slip, lattice rotation, slip transfer, and intergranular cooperative deformation. The dislocation accumulation is slower in the γ matrix, promoting uniform plastic deformation within grains via single slip, resulting in excellent intragranular deformation capability for the sample without any precipitates. In contrast, the γ″ and γ′ phases facilitate dislocation multiplication and impede dislocation motion, causing rapid dislocation pile-up within grains, leading to local stress concentrations. These stress concentrations can activate secondary slip systems early, resulting in uneven intragranular deformation and limiting the grains’ plastic deformation capacity for the sample with γ′′ and γ′. At grain boundaries, the δ phase hinders slip transfer, restricting the capacity for intergranular coordinated deformation, resulting in the formation of microcracks along the grain boundaries. These microcracks, along both the δ phase and the grain boundaries, contribute to the reduction in plasticity of the sample with δ phase. The effects of γ″ and γ′ phases are similar, as they limit grain deformation by influencing dislocation accumulation within grains, while the δ phase at grain boundaries reduces the tensile plasticity of Alloy 718 by impeding intergranular deformation coordination.
{"title":"Effect of precipitate phase on the plastic deformation behavior of Alloy 718: In-situ tensile experiment and crystal plasticity simulation","authors":"Guanghao Guo , Wenqiang Zhang , Bin Zhang , Jiachen Xu , Shuang Chen , Xianjue Ye , Yuefei Zhang , Ze Zhang","doi":"10.1016/j.ijplas.2025.104286","DOIUrl":"10.1016/j.ijplas.2025.104286","url":null,"abstract":"<div><div>In this study, in-situ tensile experiments were conducted on three samples containing different precipitate phases (δ, γ″ and γ′) to investigate the effects of these precipitates on the tensile deformation mechanisms of Alloy 718. Local plastic deformation was characterized by digital image correlation (DIC) and electron back-scatter diffraction (EBSD). The plasticity was analyzed in terms of slip, lattice rotation, slip transfer, and intergranular cooperative deformation. The dislocation accumulation is slower in the γ matrix, promoting uniform plastic deformation within grains via single slip, resulting in excellent intragranular deformation capability for the sample without any precipitates. In contrast, the γ″ and γ′ phases facilitate dislocation multiplication and impede dislocation motion, causing rapid dislocation pile-up within grains, leading to local stress concentrations. These stress concentrations can activate secondary slip systems early, resulting in uneven intragranular deformation and limiting the grains’ plastic deformation capacity for the sample with γ′′ and γ′. At grain boundaries, the δ phase hinders slip transfer, restricting the capacity for intergranular coordinated deformation, resulting in the formation of microcracks along the grain boundaries. These microcracks, along both the δ phase and the grain boundaries, contribute to the reduction in plasticity of the sample with δ phase. The effects of γ″ and γ′ phases are similar, as they limit grain deformation by influencing dislocation accumulation within grains, while the δ phase at grain boundaries reduces the tensile plasticity of Alloy 718 by impeding intergranular deformation coordination.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104286"},"PeriodicalIF":9.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471080","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}
Pub Date : 2025-02-22DOI: 10.1016/j.ijplas.2025.104287
Xiaocong Yang , Yuezhang Ju , Chengning Li , Chang Gao , Lingzhi Ba , Shipin Wu , Ce Wang , Taihao Ding , Ying Wang , Xinjie Di
In this study, the low-carbon ultra-high-strength steels with precipitation-free were prepared using quenching processes, and the co-precipitation strengthening of multi-scale Cu-rich and NiAl were designed to enhance fatigue performance through quenching-tempering (QT) and quenching-partitioning-tempering (QPT) processes respectively. The microstructure of quenched steel shows a typical mixed microstructure of lath martensite (LM) and granular bainite (GB). After aging at 550 °C for 1 h, the high density (1.945 × 1023 m-3) of B2-NiAl and B2 core-9R shell nanoparticles were uniformly co-precipitated and greatly increased the yield strength and high-cycle fatigue strength from 965 MPa and 384.6 MPa to 1548 MPa and 510.7 MPa, respectively. The substantial improvement in fatigue performance is attributed to the large number of small-sized nanoparticles that hinder the movement of dislocations to form high-density dislocation tangles (HDDTs) and cell structures, reducing the stress concentration at grain boundaries. Furthermore, geometric phase analysis (GPA) revealed the existence of micro-strain around small-sized multi-component precipitates, which is less likely to cause micro-crack initiation, thereby enhancing the fatigue performance. After QPT treatment, the co-precipitated nanoparticles exhibited multi-scale distribution with a significantly reduced number density of 1.005 × 1023 m-3, and the typical large-sized FCC-Cu particles are identified, which weakens the precipitation strengthening and leads to the yield strength and fatigue strength reached 1396 MPa and 424.5 MPa respectively. Furthermore, the GNDs obviously accumulate at the interface between reversed austenite (RA) and matrix by the movement of dislocations and bypassed nanoparticles, which increases the tendency of microcrack initiation at the interface. In addition, the high strain accumulated at the interface of FCC-Cu particles increases the risk of fatigue damage and limits the improvement of fatigue performance.
{"title":"Enhancing fatigue life of low-carbon ultra-high strength steel by inducing multi-component precipitates","authors":"Xiaocong Yang , Yuezhang Ju , Chengning Li , Chang Gao , Lingzhi Ba , Shipin Wu , Ce Wang , Taihao Ding , Ying Wang , Xinjie Di","doi":"10.1016/j.ijplas.2025.104287","DOIUrl":"10.1016/j.ijplas.2025.104287","url":null,"abstract":"<div><div>In this study, the low-carbon ultra-high-strength steels with precipitation-free were prepared using quenching processes, and the co-precipitation strengthening of multi-scale Cu-rich and NiAl were designed to enhance fatigue performance through quenching-tempering (QT) and quenching-partitioning-tempering (QPT) processes respectively. The microstructure of quenched steel shows a typical mixed microstructure of lath martensite (LM) and granular bainite (GB). After aging at 550 °C for 1 h, the high density (1.945 × 10<sup>23</sup> m<sup>-3</sup>) of B2-NiAl and B2 core-9R shell nanoparticles were uniformly co-precipitated and greatly increased the yield strength and high-cycle fatigue strength from 965 MPa and 384.6 MPa to 1548 MPa and 510.7 MPa, respectively. The substantial improvement in fatigue performance is attributed to the large number of small-sized nanoparticles that hinder the movement of dislocations to form high-density dislocation tangles (HDDTs) and cell structures, reducing the stress concentration at grain boundaries. Furthermore, geometric phase analysis (GPA) revealed the existence of micro-strain around small-sized multi-component precipitates, which is less likely to cause micro-crack initiation, thereby enhancing the fatigue performance. After QPT treatment, the co-precipitated nanoparticles exhibited multi-scale distribution with a significantly reduced number density of 1.005 × 10<sup>23</sup> m<sup>-3</sup>, and the typical large-sized FCC-Cu particles are identified, which weakens the precipitation strengthening and leads to the yield strength and fatigue strength reached 1396 MPa and 424.5 MPa respectively. Furthermore, the GNDs obviously accumulate at the interface between reversed austenite (RA) and matrix by the movement of dislocations and bypassed nanoparticles, which increases the tendency of microcrack initiation at the interface. In addition, the high strain accumulated at the interface of FCC-Cu particles increases the risk of fatigue damage and limits the improvement of fatigue performance.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104287"},"PeriodicalIF":9.4,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143471082","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}
Pub Date : 2025-02-19DOI: 10.1016/j.ijplas.2025.104285
David D.S. Silva , Gustavo Bertoli , Paul Mason , Nelson D. Campos Neto , Norbert Schell , Michael J. Kaufman , Amy J. Clarke , Francisco G. Coury , Claudemiro Bolfarini
Novel face-centered cubic (FCC) phase CoCrFeMnNi-based medium- and high-entropy alloys (M/HEAs) with the following nominal compositions Co15Cr15Fe50Mn10Ni10 (Co15Cr15), Co20Cr20Fe40Mn10Ni10 (Co20Cr20), and Co25Cr25Fe30Mn10Ni10 (Co25Cr25) in at.%, were designed via metastability-engineering strategy to trigger different deformation mechanisms, such as twinning-induced plasticity (TWIP) and/or transformation-induced plasticity (TRIP). Both mechanisms are governed by the stacking fault energy (SFE), which depends on composition. Fully recrystallized samples with different grain sizes ranging from 2.7 to 102.5 µm were obtained. Tensile tests were conducted at room temperature (298 K), and Hall-Petch relationships were established. The annealed and deformed samples were characterized by a combination of electron backscatter diffraction (EBSD), high-energy synchrotron X-ray diffraction (HE-SXRD), and transmission electron microscopy (TEM) to correlate deformation microstructures with phase stability. It was revealed that grain refinement was more effective in the Co25Cr25 alloy, given by the high Hall-Petch coefficients ( = 516 MPa.µm1/2 and = 198 MPa). For a grain size of 2.7 µm, the product of yield strength (∼500 MPa) and uniform elongation (∼45 %) in the Co25Cr25 alloy reaches its maximum (∼23 GPa%), achieving the optimal strength-ductility synergy. Due to the decrease in the effective SFE (from 26.6 to 3.5 mJ m-2), a transition in the dominant deformation behavior occurred from TWIP (Co15Cr15) to TWIP/TRIP (Co20Cr20) and finally to TRIP (Co25Cr25). The calculations further showed that and the total dislocation density exhibit an inverse relationship with the effective SFE. Such findings highlight the potential of compositional tuning for developing high-performance M/HEAs with designed deformation mechanisms.
{"title":"Metastability-engineering strategy in CoCrFeMnNi-based medium- and high-entropy alloys: Unraveling the interplay with recrystallization, grain growth, and mechanical properties","authors":"David D.S. Silva , Gustavo Bertoli , Paul Mason , Nelson D. Campos Neto , Norbert Schell , Michael J. Kaufman , Amy J. Clarke , Francisco G. Coury , Claudemiro Bolfarini","doi":"10.1016/j.ijplas.2025.104285","DOIUrl":"10.1016/j.ijplas.2025.104285","url":null,"abstract":"<div><div>Novel face-centered cubic (FCC) phase CoCrFeMnNi-based medium- and high-entropy alloys (M/HEAs) with the following nominal compositions Co<sub>15</sub>Cr<sub>15</sub>Fe<sub>50</sub>Mn<sub>10</sub>Ni<sub>10</sub> (Co15Cr15), Co<sub>20</sub>Cr<sub>20</sub>Fe<sub>40</sub>Mn<sub>10</sub>Ni<sub>10</sub> (Co20Cr20), and Co<sub>25</sub>Cr<sub>25</sub>Fe<sub>30</sub>Mn<sub>10</sub>Ni<sub>10</sub> (Co25Cr25) in at.%, were designed via metastability-engineering strategy to trigger different deformation mechanisms, such as twinning-induced plasticity (TWIP) and/or transformation-induced plasticity (TRIP). Both mechanisms are governed by the stacking fault energy (SFE), which depends on composition. Fully recrystallized samples with different grain sizes ranging from 2.7 to 102.5 µm were obtained. Tensile tests were conducted at room temperature (298 K), and Hall-Petch relationships were established. The annealed and deformed samples were characterized by a combination of electron backscatter diffraction (EBSD), high-energy synchrotron X-ray diffraction (HE-SXRD), and transmission electron microscopy (TEM) to correlate deformation microstructures with phase stability. It was revealed that grain refinement was more effective in the Co25Cr25 alloy, given by the high Hall-Petch coefficients (<span><math><msub><mi>k</mi><mrow><mi>H</mi><mi>P</mi></mrow></msub></math></span> = 516 MPa.µm<sup>1/2</sup> and <span><math><msub><mi>σ</mi><mn>0</mn></msub></math></span> = 198 MPa). For a grain size of 2.7 µm, the product of yield strength (∼500 MPa) and uniform elongation (∼45 %) in the Co25Cr25 alloy reaches its maximum (∼23 GPa%), achieving the optimal strength-ductility synergy. Due to the decrease in the effective SFE (from 26.6 to 3.5 mJ m<sup>-2</sup>), a transition in the dominant deformation behavior occurred from TWIP (Co15Cr15) to TWIP/TRIP (Co20Cr20) and finally to TRIP (Co25Cr25). The calculations further showed that <span><math><msub><mi>k</mi><mrow><mi>H</mi><mi>P</mi></mrow></msub></math></span> and the total dislocation density exhibit an inverse relationship with the effective SFE. Such findings highlight the potential of compositional tuning for developing high-performance M/HEAs with designed deformation mechanisms.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104285"},"PeriodicalIF":9.4,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143451446","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}
Pub Date : 2025-02-16DOI: 10.1016/j.ijplas.2025.104275
Zhen Yu , Xingyue Sun , Ruisi Xing , Xu Chen
The ratcheting behavior of plastic deformation accumulation under asymmetric loading poses significant risks to the safe service of engineering structures. For accurate prediction of the ratcheting behavior of the material, a physics-informed multimodal network named Dual Stream GRU (DSGRU) model is proposed with training and validation of 316LN stainless steel samples. By incorporating the unrecoverable characteristic of ratcheting behavior into the loss function, there is a significant improvement in the prediction and generalization performance of the DSGRU model. Meanwhile, the multimodal network enables the model to consider material properties at different temperatures. Through sufficient constitutive simulation samples, the DSGRU model with optimal architecture is well-trained and transferred to small sample experimental samples with fine-tuning method. Whether in pre-training or transfer learning processes, the physics-informed loss function ensures the physical consistency of predicted results.
{"title":"Unified prediction of uniaxial ratcheting deformation at elevated temperatures with physics-informed multimodal network","authors":"Zhen Yu , Xingyue Sun , Ruisi Xing , Xu Chen","doi":"10.1016/j.ijplas.2025.104275","DOIUrl":"10.1016/j.ijplas.2025.104275","url":null,"abstract":"<div><div>The ratcheting behavior of plastic deformation accumulation under asymmetric loading poses significant risks to the safe service of engineering structures. For accurate prediction of the ratcheting behavior of the material, a physics-informed multimodal network named Dual Stream GRU (DSGRU) model is proposed with training and validation of 316LN stainless steel samples. By incorporating the unrecoverable characteristic of ratcheting behavior into the loss function, there is a significant improvement in the prediction and generalization performance of the DSGRU model. Meanwhile, the multimodal network enables the model to consider material properties at different temperatures. Through sufficient constitutive simulation samples, the DSGRU model with optimal architecture is well-trained and transferred to small sample experimental samples with fine-tuning method. Whether in pre-training or transfer learning processes, the physics-informed loss function ensures the physical consistency of predicted results.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104275"},"PeriodicalIF":9.4,"publicationDate":"2025-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417283","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}
Pub Date : 2025-02-15DOI: 10.1016/j.ijplas.2025.104270
Shaorong Liu , Yukai Xiong , Jianfeng Zhao , Baoxi Liu , Wenwang Wu , Xu Zhang
Ultrafine elongated grain (UFEG) steel, characterized by its unique multi-level and multi-scale laminated heterogeneous structure, shows considerable promise in addressing the challenge of balancing high strength and toughness in metallic materials. In this work, we develop a coupled nonlocal crystal plasticity and damage phase field model. We derived the dislocation flux term from this model to introduce geometrically necessary dislocation (GND) and back stress to reflect the heterogeneous deformation of the material, and corrected the critical plastic work density term based on the relationship between grain boundary misorientation and grain boundary energy to investigate the strengthening and softening mechanisms of medium carbon steel with UFEG structure under uniaxial tensile deformation. Simulation results indicate that the strengthening effects of GNDs and back stress are closely linked to the material's initial dislocation density and grain size. Higher initial dislocation densities and larger grain sizes limit these effects. Moreover, a higher grain aspect ratio enhances the strengthening effect of GNDs. Different textures significantly affect the tensile properties of the material. The experimentally obtained <110>//RD fiber texture provides some strengthening effect, but there remains a gap compared to the ideal fiber texture. Damage initiates in the elongated grains, but the equiaxed grains help slow its progression. High-angle grain boundaries promote intergranular damage, which restricts the spread of intragranular damage. These boundaries are also critical in the formation of delamination cracks within the BCC material. These insights provide a foundation for understanding the role of grain morphology and GND density in the deformation and failure mechanisms of dual-heterostructured medium carbon steels, offering potential guidance for optimizing microstructure design in these specific material systems.
{"title":"Nonlocal crystal plasticity and damage modeling of dual-heterostructured steel for strengthening and failure analysis","authors":"Shaorong Liu , Yukai Xiong , Jianfeng Zhao , Baoxi Liu , Wenwang Wu , Xu Zhang","doi":"10.1016/j.ijplas.2025.104270","DOIUrl":"10.1016/j.ijplas.2025.104270","url":null,"abstract":"<div><div>Ultrafine elongated grain (UFEG) steel, characterized by its unique multi-level and multi-scale laminated heterogeneous structure, shows considerable promise in addressing the challenge of balancing high strength and toughness in metallic materials. In this work, we develop a coupled nonlocal crystal plasticity and damage phase field model. We derived the dislocation flux term from this model to introduce geometrically necessary dislocation (GND) and back stress to reflect the heterogeneous deformation of the material, and corrected the critical plastic work density term based on the relationship between grain boundary misorientation and grain boundary energy to investigate the strengthening and softening mechanisms of medium carbon steel with UFEG structure under uniaxial tensile deformation. Simulation results indicate that the strengthening effects of GNDs and back stress are closely linked to the material's initial dislocation density and grain size. Higher initial dislocation densities and larger grain sizes limit these effects. Moreover, a higher grain aspect ratio enhances the strengthening effect of GNDs. Different textures significantly affect the tensile properties of the material. The experimentally obtained <110>//RD fiber texture provides some strengthening effect, but there remains a gap compared to the ideal fiber texture. Damage initiates in the elongated grains, but the equiaxed grains help slow its progression. High-angle grain boundaries promote intergranular damage, which restricts the spread of intragranular damage. These boundaries are also critical in the formation of delamination cracks within the BCC material. These insights provide a foundation for understanding the role of grain morphology and GND density in the deformation and failure mechanisms of dual-heterostructured medium carbon steels, offering potential guidance for optimizing microstructure design in these specific material systems.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104270"},"PeriodicalIF":9.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417323","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}
Pub Date : 2025-02-15DOI: 10.1016/j.ijplas.2025.104283
Yuanyuan Zhang , Xiping Cui , Lingfei Chen , Naonao Gao , Xuanchang Zhang , Zhiqi Wang , Guanghui Cong , Xiangxin Zhai , Jiawei Luo , Yifan Zhang , Junfeng Chen , Lin Geng , Lujun Huang
To meeting the double demands of structural weight reduction and performance improvement of aerospace vehicle, conventional high-temperature titanium alloys or titanium matrix composites (TMCs) are encountering a huge challenge that the room-temperature ductility will be inevitably deteriorated in pursuit of enhancing the elevated high-temperature strength. The present work proposes a feasible strategy for resolving this contradiction by constructing a novel bimodal architecture and introducing the multiscale reinforcements of microsized TiB whiskers and micro/nanosized Y2O3 particles. The unique bimodal microstructure consists of primary microsized αp/β lath clusters and micro/nano basketweave-like structure composing of αp, secondary nanosized αs and β laths. It is noteworthy that the bimodal (TiB+Y2O3)/Ti composite exhibits excellent mechanical properties with the ultimate tensile strength (UTS) of 1318 MPa with the total elongation to failure (EL) of 10.5 % at room temperature, and UTS of 934 MPa with EL of 23 % at 600 °C, far higher that of the reported 600 °C high temperature titanium alloys or TMCs. In-situ investigations indicate the postponed strain localization, the activated extra 〈c + a〉 dislocations within αp laths, and the heterogeneous deformation induced (HDI) hardening caused by the unique bimodal microstructure, synergistically promoted the ductility of bimodal (TiB+Y2O3)/Ti composite. While the strength enhancement at room temperature and 600 °C is attributed to the synergistic strengthening effect of nanosized αs, microsized TiB whiskers and micro/nanosized Y2O3 particles and HDI strengthening. These findings provide a new insight for improving mechanical properties of metal matrix composites.
{"title":"Simultaneously enhancing room-temperature strength-ductility synergy and high-temperature performance of titanium matrix composites via building a unique bimodal architecture with multi-scale reinforcements","authors":"Yuanyuan Zhang , Xiping Cui , Lingfei Chen , Naonao Gao , Xuanchang Zhang , Zhiqi Wang , Guanghui Cong , Xiangxin Zhai , Jiawei Luo , Yifan Zhang , Junfeng Chen , Lin Geng , Lujun Huang","doi":"10.1016/j.ijplas.2025.104283","DOIUrl":"10.1016/j.ijplas.2025.104283","url":null,"abstract":"<div><div>To meeting the double demands of structural weight reduction and performance improvement of aerospace vehicle, conventional high-temperature titanium alloys or titanium matrix composites (TMCs) are encountering a huge challenge that the room-temperature ductility will be inevitably deteriorated in pursuit of enhancing the elevated high-temperature strength. The present work proposes a feasible strategy for resolving this contradiction by constructing a novel bimodal architecture and introducing the multiscale reinforcements of microsized TiB whiskers and micro/nanosized Y<sub>2</sub>O<sub>3</sub> particles. The unique bimodal microstructure consists of primary microsized α<sub>p</sub>/β lath clusters and micro/nano basketweave-like structure composing of α<sub>p</sub>, secondary nanosized α<sub>s</sub> and β laths. It is noteworthy that the bimodal (TiB+Y<sub>2</sub>O<sub>3</sub>)/Ti composite exhibits excellent mechanical properties with the ultimate tensile strength (UTS) of 1318 MPa with the total elongation to failure (EL) of 10.5 % at room temperature, and UTS of 934 MPa with EL of 23 % at 600 °C, far higher that of the reported 600 °C high temperature titanium alloys or TMCs. In-situ investigations indicate the postponed strain localization, the activated extra 〈c + a〉 dislocations within α<sub>p</sub> laths, and the heterogeneous deformation induced (HDI) hardening caused by the unique bimodal microstructure, synergistically promoted the ductility of bimodal (TiB+Y<sub>2</sub>O<sub>3</sub>)/Ti composite. While the strength enhancement at room temperature and 600 °C is attributed to the synergistic strengthening effect of nanosized α<sub>s</sub>, microsized TiB whiskers and micro/nanosized Y<sub>2</sub>O<sub>3</sub> particles and HDI strengthening. These findings provide a new insight for improving mechanical properties of metal matrix composites.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"187 ","pages":"Article 104283"},"PeriodicalIF":9.4,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143417281","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}
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