Pub Date : 2025-04-12DOI: 10.1016/j.ijplas.2025.104339
Wen An, Jiang-Peng Yang, Chuan-Zhi Liu, Qi-Lin Xiong
As one of the most important plastic deformation mechanisms of high-entropy alloys, deformation twinning can increase the strength without losing plasticity. Nevertheless, recent studies have shown that high-density twins can form "soft spots" and promote the occurrence of shear localization failure at high strain rates. The extent to which deformation twins contribute to the formation of shear localization remains unclear. In this study, a series of dynamic uniaxial compression experiments have been performed with Al0.1CoCrFeNi HEAs under different conditions to disclose the dynamic recrystallization mechanism. Corresponding to the dynamic recrystallization and plastic dissipation mechanisms at high strain rates, a dislocation entanglement model has been established in conjunction with deformation twinning and physically based heat dissipation to capture the process of shear localization formation. The dislocation entanglement model has been integrated into the theoretical framework of crystal plasticity to perform finite element simulations of high-strain rate deformations. The results predicted by the crystal plasticity simulations are in good agreement with the experimental data, confirming the rationality of the new constitutive model. Deformation twinning can significantly improve strain hardening ability and resistance to shear localization. Interestingly, when the volume fraction of twins reaches a certain level, the mechanism of twin-assisted continuous dynamic recrystallization is triggered due to the interaction between dislocations and twins, resulting in the formation of many “soft spots” (corresponding to the twin region with high density). Upon further deformation, these “soft spots” continue to evolve and aggregate to eventually form the bands of shear localization. Our results can be used for the microstructure design of dynamic high-performance metals with high strength and plasticity to artificially control shear localization.
{"title":"Effect of Twinning on Shear Localization of Al0.1CoCrFeNi High Entropy Alloy at High Strain Rates: Experiment and Crystal Plasticity Modeling","authors":"Wen An, Jiang-Peng Yang, Chuan-Zhi Liu, Qi-Lin Xiong","doi":"10.1016/j.ijplas.2025.104339","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104339","url":null,"abstract":"As one of the most important plastic deformation mechanisms of high-entropy alloys, deformation twinning can increase the strength without losing plasticity. Nevertheless, recent studies have shown that high-density twins can form \"soft spots\" and promote the occurrence of shear localization failure at high strain rates. The extent to which deformation twins contribute to the formation of shear localization remains unclear. In this study, a series of dynamic uniaxial compression experiments have been performed with Al<sub>0.1</sub>CoCrFeNi HEAs under different conditions to disclose the dynamic recrystallization mechanism. Corresponding to the dynamic recrystallization and plastic dissipation mechanisms at high strain rates, a dislocation entanglement model has been established in conjunction with deformation twinning and physically based heat dissipation to capture the process of shear localization formation. The dislocation entanglement model has been integrated into the theoretical framework of crystal plasticity to perform finite element simulations of high-strain rate deformations. The results predicted by the crystal plasticity simulations are in good agreement with the experimental data, confirming the rationality of the new constitutive model. Deformation twinning can significantly improve strain hardening ability and resistance to shear localization. Interestingly, when the volume fraction of twins reaches a certain level, the mechanism of twin-assisted continuous dynamic recrystallization is triggered due to the interaction between dislocations and twins, resulting in the formation of many “soft spots” (corresponding to the twin region with high density). Upon further deformation, these “soft spots” continue to evolve and aggregate to eventually form the bands of shear localization. Our results can be used for the microstructure design of dynamic high-performance metals with high strength and plasticity to artificially control shear localization.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"183 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822646","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}
The microstructure and tensile behavior of laser powder bed fusion (LPBF) processed 316L austenitic stainless steel (316L) and Inconel 718 Ni-based superalloy (IN718) coupons with compositionally graded joints (CGJ), spanning lengths of 0, 10 and 20 mm, in the as built and heat-treated conditions, are investigated. In the as built condition, the microstructure of pure 316L and IN718 ligaments consist of micron-sized sub-grains present within <001> textured columnar grains, whereas CGJs contain a mixture of randomly textured columnar and equiaxed grains. Heat treatment, involving solutionizing above 1040 °C with subsequent ageing at 720 and 620 °C, leads to the recrystallization of portions with > 85 wt.% IN718 of the CGJ coupons. Higher composition gradient span, in both the as built and heat-treated states, improves the yield and tensile strengths of the specimens, but compromises ductility. Tension-compression asymmetry, which also progressively increases with increasing strain and the CGJ span, is observed in all the specimens. Simulations indicate that CGJs with shallower composition gradients have lower fluctuations in the stress triaxiality, von mises equivalent stress, and the maximum shear stress compared to those with sharper gradients. These mechanical property variations and the deformation characteristics of the CGJ specimens are analyzed in detail by considering the varying degrees of plastic constraint on the 100 wt.% 316L and the degree of interactions between strain-generated dislocations and geometrically necessary dislocations. Finally, the effectiveness of CGJ in enhancing the tensile properties of the 316L/IN718 joints and the geometrical considerations for designing such joints for different alloy combinations is discussed.
{"title":"Tensile Behavior of Additively Manufactured Inconel 718 and Stainless Steel 316L with Compositionally Graded Joints","authors":"Yaojie Wen, Yang Gao, Ramasubramanian Lakshmi Narayan, Wei Cai, Pei Wang, Xiaoding Wei, Baicheng Zhang, Upadrasta Ramamurty, Xuanhui Qu","doi":"10.1016/j.ijplas.2025.104342","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104342","url":null,"abstract":"The microstructure and tensile behavior of laser powder bed fusion (LPBF) processed 316L austenitic stainless steel (316L) and Inconel 718 Ni-based superalloy (IN718) coupons with compositionally graded joints (CGJ), spanning lengths of 0, 10 and 20 mm, in the as built and heat-treated conditions, are investigated. In the as built condition, the microstructure of pure 316L and IN718 ligaments consist of micron-sized sub-grains present within <001> textured columnar grains, whereas CGJs contain a mixture of randomly textured columnar and equiaxed grains. Heat treatment, involving solutionizing above 1040 °C with subsequent ageing at 720 and 620 °C, leads to the recrystallization of portions with > 85 wt.% IN718 of the CGJ coupons. Higher composition gradient span, in both the as built and heat-treated states, improves the yield and tensile strengths of the specimens, but compromises ductility. Tension-compression asymmetry, which also progressively increases with increasing strain and the CGJ span, is observed in all the specimens. Simulations indicate that CGJs with shallower composition gradients have lower fluctuations in the stress triaxiality, von mises equivalent stress, and the maximum shear stress compared to those with sharper gradients. These mechanical property variations and the deformation characteristics of the CGJ specimens are analyzed in detail by considering the varying degrees of plastic constraint on the 100 wt.% 316L and the degree of interactions between strain-generated dislocations and geometrically necessary dislocations. Finally, the effectiveness of CGJ in enhancing the tensile properties of the 316L/IN718 joints and the geometrical considerations for designing such joints for different alloy combinations is discussed.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"59 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822647","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 : 2025-04-11DOI: 10.1016/j.ijplas.2025.104340
Jie Li, Yaxin Zhu, Lv Zhao, Shuang Liang, Minsheng Huang, Zhenhuan Li
Refractory high-entropy alloys (RHEAs) exhibit excellent anti-irradiation properties, making them promising candidates for application in advanced nuclear reactors. In this study, molecular statics (MS) and molecular dynamics (MD) simulations are conducted to investigate the local unstable stacking fault energies (USFE) in RHEAs induced by primary knock-on atoms (PKAs) of displacement cascades. Based on these atomistic simulations, a phase-field dislocation dynamics (PFDD) model is developed, incorporating the effects of chemical composition fluctuations and displacement cascades on local USFE in RHEAs using a random statistical approach. Using this PFDD model, the planar motion of edge and screw dislocations, as well as the cross-slip behavior of screw dislocations, in WTaCrV are examined. The results indicate that the cascade region can effectively pin edge dislocations and hinder the nucleation of kink pairs in screw dislocations, leading to irradiation hardening. However, the low local USFE caused by chemical composition fluctuations in WTaCrV allows edge dislocation segments near pinning sites to bow out, dragging pinned dislocation segments and reducing the pinning effect. Additionally, the low local USFE promotes the nucleation and migration of kink pairs in screw dislocations. Furthermore, for the case of screw dislocation cross-slip, the irradiation hardening is alleviated as nonplanar kink pairs recede to the habit plane. These simulation results reveal the mesoscale internal mechanisms underlying anti-irradiation hardening in RHEAs. Based on these findings, mesoscale theoretical models describing dislocation motion and irradiation hardening are proposed, and they are verified experimentally. With these models, the irradiation hardening behavior of other RHEAs can be predicted. These findings can guide the design and preparation of advanced anti-irradiation RHEAs and contribute to the development of upscaled theoretical models and simulation methods.
{"title":"Investigate irradiation hardening behavior in BCC refractory high-entropy alloys using phase-field modeling informed by atomistic simulations of displacement cascades","authors":"Jie Li, Yaxin Zhu, Lv Zhao, Shuang Liang, Minsheng Huang, Zhenhuan Li","doi":"10.1016/j.ijplas.2025.104340","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104340","url":null,"abstract":"Refractory high-entropy alloys (RHEAs) exhibit excellent anti-irradiation properties, making them promising candidates for application in advanced nuclear reactors. In this study, molecular statics (MS) and molecular dynamics (MD) simulations are conducted to investigate the local unstable stacking fault energies (USFE) in RHEAs induced by primary knock-on atoms (PKAs) of displacement cascades. Based on these atomistic simulations, a phase-field dislocation dynamics (PFDD) model is developed, incorporating the effects of chemical composition fluctuations and displacement cascades on local USFE in RHEAs using a random statistical approach. Using this PFDD model, the planar motion of edge and screw dislocations, as well as the cross-slip behavior of screw dislocations, in WTaCrV are examined. The results indicate that the cascade region can effectively pin edge dislocations and hinder the nucleation of kink pairs in screw dislocations, leading to irradiation hardening. However, the low local USFE caused by chemical composition fluctuations in WTaCrV allows edge dislocation segments near pinning sites to bow out, dragging pinned dislocation segments and reducing the pinning effect. Additionally, the low local USFE promotes the nucleation and migration of kink pairs in screw dislocations. Furthermore, for the case of screw dislocation cross-slip, the irradiation hardening is alleviated as nonplanar kink pairs recede to the habit plane. These simulation results reveal the mesoscale internal mechanisms underlying anti-irradiation hardening in RHEAs. Based on these findings, mesoscale theoretical models describing dislocation motion and irradiation hardening are proposed, and they are verified experimentally. With these models, the irradiation hardening behavior of other RHEAs can be predicted. These findings can guide the design and preparation of advanced anti-irradiation RHEAs and contribute to the development of upscaled theoretical models and simulation methods.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"102 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820082","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}
A new plasticity-induced internal length mean field model (ILMF) is developed, based on statistical analyses of geometrically necessary dislocation (GND) densities and total dislocation densities estimated from EBSD and nanoindentation data, respectively. It is applied to a single phase ferritic Al-killed steel, which plastically deforms with the occurrence of heterogeneous intra-granular fields. During tensile tests up to 18% of overall plastic strain, the deformation maps of GND densities due to intra-granular plastic strain gradients are obtained together with nano-hardness maps. The Nye tensor (or dislocation density tensor) is calculated from the 2D EBSD orientations to estimate the intragranular GND density, while a mechanistic model is used to estimate the intragranular total dislocation density from nano-hardness measurements. These data are quantified as a function of the distance to grain boundaries (GBs) to study the development of such plastic strain gradients in the vicinity of GBs. The novel methodology lies in extracting the evolution law of a single plasticity-induced internal length, denoted <span><span style=""></span><span data-mathml='<math xmlns="http://www.w3.org/1998/Math/MathML"><mi is="true">λ</mi></math>' role="presentation" style="font-size: 90%; display: inline-block; position: relative;" tabindex="0"><svg aria-hidden="true" focusable="false" height="1.971ex" role="img" style="vertical-align: -0.235ex;" viewbox="0 -747.2 583.5 848.5" width="1.355ex" xmlns:xlink="http://www.w3.org/1999/xlink"><g fill="currentColor" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)"><g is="true"><use xlink:href="#MJMATHI-3BB"></use></g></g></svg><span role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mi is="true">λ</mi></math></span></span><script type="math/mml"><math><mi is="true">λ</mi></math></script></span>, from the statistical analysis of GND and total dislocation densities spatial distribution. Hence, it is introduced as an evolving variable in an elastoviscoplastic self-consistent model (EVPSC) for a two-phase composite as a new internal mean field (ILMF) approach. Both experimentally quantified microstructural internal lengths defined by the mean grain size and the evolving layer <span><span style=""></span><span data-mathml='<math xmlns="http://www.w3.org/1998/Math/MathML"><mi is="true">λ</mi></math>' role="presentation" style="font-size: 90%; display: inline-block; position: relative;" tabindex="0"><svg aria-hidden="true" focusable="false" height="1.971ex" role="img" style="vertical-align: -0.235ex;" viewbox="0 -747.2 583.5 848.5" width="1.355ex" xmlns:xlink="http://www.w3.org/1999/xlink"><g fill="currentColor" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)"><g is="true"><use xlink:href="#MJMATHI-3BB"></use></g></g></svg><span role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML">
{"title":"A plasticity-induced internal length mean field model based on statistical analyses of EBSD and nanoindentation data","authors":"Layal Chamma, Jean-Marc Pipard, Artem Arlazarov, Thiebaud Richeton, Stéphane Berbenni","doi":"10.1016/j.ijplas.2025.104327","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104327","url":null,"abstract":"A new plasticity-induced internal length mean field model (ILMF) is developed, based on statistical analyses of geometrically necessary dislocation (GND) densities and total dislocation densities estimated from EBSD and nanoindentation data, respectively. It is applied to a single phase ferritic Al-killed steel, which plastically deforms with the occurrence of heterogeneous intra-granular fields. During tensile tests up to 18% of overall plastic strain, the deformation maps of GND densities due to intra-granular plastic strain gradients are obtained together with nano-hardness maps. The Nye tensor (or dislocation density tensor) is calculated from the 2D EBSD orientations to estimate the intragranular GND density, while a mechanistic model is used to estimate the intragranular total dislocation density from nano-hardness measurements. These data are quantified as a function of the distance to grain boundaries (GBs) to study the development of such plastic strain gradients in the vicinity of GBs. The novel methodology lies in extracting the evolution law of a single plasticity-induced internal length, denoted <span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi is=\"true\">&#x3BB;</mi></math>' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"1.971ex\" role=\"img\" style=\"vertical-align: -0.235ex;\" viewbox=\"0 -747.2 583.5 848.5\" width=\"1.355ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"><g is=\"true\"><use xlink:href=\"#MJMATHI-3BB\"></use></g></g></svg><span role=\"presentation\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi is=\"true\">λ</mi></math></span></span><script type=\"math/mml\"><math><mi is=\"true\">λ</mi></math></script></span>, from the statistical analysis of GND and total dislocation densities spatial distribution. Hence, it is introduced as an evolving variable in an elastoviscoplastic self-consistent model (EVPSC) for a two-phase composite as a new internal mean field (ILMF) approach. Both experimentally quantified microstructural internal lengths defined by the mean grain size and the evolving layer <span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi is=\"true\">&#x3BB;</mi></math>' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"1.971ex\" role=\"img\" style=\"vertical-align: -0.235ex;\" viewbox=\"0 -747.2 583.5 848.5\" width=\"1.355ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"><g is=\"true\"><use xlink:href=\"#MJMATHI-3BB\"></use></g></g></svg><span role=\"presentation\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\">","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"75 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143813918","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 : 2025-04-09DOI: 10.1016/j.ijplas.2025.104319
Kushagra Tiwari , Aayush Trivedi , G. Bharat Reddy , Bhupendra K. Kumawat , Akhil Bhardwaj , R.K. Singh Raman , Rhys Jones , Alankar Alankar
The limited use of additively manufactured Ti-6Al-4V (AM Ti64) alloy in critical load–bearing applications stems from an incomplete understanding of its fatigue behavior, the underlying causes and mechanisms, and the absence of reliable predictive modeling. This study aims to bridge this gap by attempting to aid a microstructure–sensitive modeling with the number of cycles to failure. Low cycle fatigue (LCF) tests are performed to failure at room temperature with five different strain amplitudes, with cyclic softening noted in all tests. A crystal plasticity model is developed and used for analyzing the fatigue indicator parameters (FIPs). Synthetic microstructures that statistically resemble the experimentally observed microstructure obtained using Electron Backscatter Diffraction (EBSD), are used. Grain-averaged and Band-averaged Fatemi–Socie FIPs are employed to evaluate the likelihood of crack initiation. These FIPs are derived from the output of CPFE model and volume-averaged for each strain amplitude. Following the elastic–plastic shakedown, the highest 5% of volume-averaged FIPs are analyzed using a Gumbel extreme value distribution. A Bayesian inference approach is used to associate the Gumbel distribution’s characteristics of FIPs with fatigue life, demonstrating a strong correlation with the experimental data on fatigue life. This work shows that a consistent correlation between FIPs and the number of cycles to failure can be established, offering a predictive tool for fatigue life assessment.
{"title":"Crystal plasticity modeling and data-driven approach for fatigue life estimation of additively manufactured Ti-6Al-4V alloy","authors":"Kushagra Tiwari , Aayush Trivedi , G. Bharat Reddy , Bhupendra K. Kumawat , Akhil Bhardwaj , R.K. Singh Raman , Rhys Jones , Alankar Alankar","doi":"10.1016/j.ijplas.2025.104319","DOIUrl":"10.1016/j.ijplas.2025.104319","url":null,"abstract":"<div><div>The limited use of additively manufactured Ti-6Al-4V (AM Ti64) alloy in critical load–bearing applications stems from an incomplete understanding of its fatigue behavior, the underlying causes and mechanisms, and the absence of reliable predictive modeling. This study aims to bridge this gap by attempting to aid a microstructure–sensitive modeling with the number of cycles to failure. Low cycle fatigue (LCF) tests are performed to failure at room temperature with five different strain amplitudes, with cyclic softening noted in all tests. A crystal plasticity model is developed and used for analyzing the fatigue indicator parameters (FIPs). Synthetic microstructures that statistically resemble the experimentally observed microstructure obtained using Electron Backscatter Diffraction (EBSD), are used. Grain-averaged and Band-averaged Fatemi–Socie FIPs are employed to evaluate the likelihood of crack initiation. These FIPs are derived from the output of CPFE model and volume-averaged for each strain amplitude. Following the elastic–plastic shakedown, the highest 5% of volume-averaged FIPs are analyzed using a Gumbel extreme value distribution. A Bayesian inference approach is used to associate the Gumbel distribution’s characteristics of FIPs with fatigue life, demonstrating a strong correlation with the experimental data on fatigue life. This work shows that a consistent correlation between FIPs and the number of cycles to failure can be established, offering a predictive tool for fatigue life assessment.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"189 ","pages":"Article 104319"},"PeriodicalIF":9.4,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806251","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 : 2025-04-09DOI: 10.1016/j.ijplas.2025.104330
X.Y. Sheng, Z.X. Shang, Y.F. Zhang, K. Xu, N.A. Richter, A.Y. Shang, H. Wang, X. Zhang
Strengthening of aluminum (Al) alloys is commonly achieved through precipitation by ageing. However, achieving well dispersed fine precipitates requires a meticulous heat treatment schedule. Here we report sputter-deposited nanocrystalline Al-Pd alloy with nanolaminates, mimicking the structure of vertically aligned nanocomposite (VAN). The nanolaminate consists of alternating Al-Pd solid solution and Al4Pd intermetallic phase. The periodic composition fluctuation suggests the occurrence of spinodal decomposition. The Al-12.4Pd alloy exhibits a high flow stress of 2.2 GPa with significant work hardening ability, as evidenced by in situ micropillar compression tests performed in a scanning electron microscope. The unique VAN structure induced strengthening and deformation mechanisms are discussed. This study offers a fresh perspective for the design of high-strength deformable Al alloys.
{"title":"Ultra-high Strength, Deformable Nanocrystalline Al-Pd Alloys","authors":"X.Y. Sheng, Z.X. Shang, Y.F. Zhang, K. Xu, N.A. Richter, A.Y. Shang, H. Wang, X. Zhang","doi":"10.1016/j.ijplas.2025.104330","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104330","url":null,"abstract":"Strengthening of aluminum (Al) alloys is commonly achieved through precipitation by ageing. However, achieving well dispersed fine precipitates requires a meticulous heat treatment schedule. Here we report sputter-deposited nanocrystalline Al-Pd alloy with nanolaminates, mimicking the structure of vertically aligned nanocomposite (VAN). The nanolaminate consists of alternating Al-Pd solid solution and Al<sub>4</sub>Pd intermetallic phase. The periodic composition fluctuation suggests the occurrence of spinodal decomposition. The Al-12.4Pd alloy exhibits a high flow stress of 2.2 GPa with significant work hardening ability, as evidenced by <em>in situ</em> micropillar compression tests performed in a scanning electron microscope. The unique VAN structure induced strengthening and deformation mechanisms are discussed. This study offers a fresh perspective for the design of high-strength deformable Al alloys.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"6 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806250","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 : 2025-04-09DOI: 10.1016/j.ijplas.2025.104329
Mingyu Lei , Jie Huang , Yanxian Li , Liqiang Zhang , Guochun Yang , Bin Wen
Mechanical constitutive relationships characterize the strain response of materials under external loading, laying the foundation for optimizing material performance and guiding engineering design. However, existing modeling methods for mechanical constitutive relationships, especially for high strain rate (HSR) loading, often rely on fitted experimental data and fail to comprehensively capture the underlying physical mechanisms. In this work, we propose a mechanical constitutive modeling with computational parameters (MCMCP) method suitable for HSR loading conditions, which establishes a quantitative link between the microstructure of materials and their macroscopic mechanical properties by fully integrating fundamental physical principles. This method couples the thermally activated dislocation unpinning mechanism with the phonon drag effect to accurately describe dislocation velocity and the influence of strain rate on plastic behavior. Additionally, a multi-mechanism coordinated strength-solving framework is introduced. It predicts the slip-twinning transition and quantitatively evaluates the contributions of various strengthening mechanisms. By incorporating microstructural evolution information, the material’s flow stress-strain response can also be predicted. Validation against simulations of pure metals and alloys confirms the effectiveness of the proposed method. This work not only enhances the understanding of micro-scale physical mechanisms for mechanical behavior but also provides a practical tool for predicting the mechanical properties under HSR loading.
{"title":"High-strain-rate mechanical constitutive modeling with computational parameters","authors":"Mingyu Lei , Jie Huang , Yanxian Li , Liqiang Zhang , Guochun Yang , Bin Wen","doi":"10.1016/j.ijplas.2025.104329","DOIUrl":"10.1016/j.ijplas.2025.104329","url":null,"abstract":"<div><div>Mechanical constitutive relationships characterize the strain response of materials under external loading, laying the foundation for optimizing material performance and guiding engineering design. However, existing modeling methods for mechanical constitutive relationships, especially for high strain rate (HSR) loading, often rely on fitted experimental data and fail to comprehensively capture the underlying physical mechanisms. In this work, we propose a mechanical constitutive modeling with computational parameters (MCMCP) method suitable for HSR loading conditions, which establishes a quantitative link between the microstructure of materials and their macroscopic mechanical properties by fully integrating fundamental physical principles. This method couples the thermally activated dislocation unpinning mechanism with the phonon drag effect to accurately describe dislocation velocity and the influence of strain rate on plastic behavior. Additionally, a multi-mechanism coordinated strength-solving framework is introduced. It predicts the slip-twinning transition and quantitatively evaluates the contributions of various strengthening mechanisms. By incorporating microstructural evolution information, the material’s flow stress-strain response can also be predicted. Validation against simulations of pure metals and alloys confirms the effectiveness of the proposed method. This work not only enhances the understanding of micro-scale physical mechanisms for mechanical behavior but also provides a practical tool for predicting the mechanical properties under HSR loading.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"189 ","pages":"Article 104329"},"PeriodicalIF":9.4,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806252","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 : 2025-04-09DOI: 10.1016/j.ijplas.2025.104331
Gangting Wang , Sangyu Luo , Yansong Guo , Ruizhe Huang , Chenguang Wang , Zhaoliang Qu
In this study, laser shock processing (LSP) was used to enhance the mechanical properties of CrCoNi medium-entropy alloys (MEAs) by introducing the gradient microstructures (GS) within the material. Extensive microstructural characterizations confirmed a progressive distribution of nanocrystalline grains, dislocations, and deformation twins along the material's depth. Quantitative measurements of microstructural parameters at varying depths were conducted. Near the surface, the predominant microstructural evolutions were high dislocation density, twins, and grain refinement. At deeper regions, the key behaviors were nanoscale grain refinement and twin collisions. Nanoindentation and micro-pillar compression tests were employed to characterize the hardness distribution and mechanical properties at the microscale. It was found that LSP significantly improved hardness and yield strength. A quantitative relationship between GS and mechanical properties was developed, with theoretical calculations showing good agreement with experimental results. The contributions of different microstructural evolutions to hardness were individually assessed, revealing that multi-stage twins and grain refinement were the primary strengthening factors after one and ten impacts, respectively.
{"title":"Investigating the correlation between mechanical properties and gradient microstructures in laser shock peened CrCoNi alloy","authors":"Gangting Wang , Sangyu Luo , Yansong Guo , Ruizhe Huang , Chenguang Wang , Zhaoliang Qu","doi":"10.1016/j.ijplas.2025.104331","DOIUrl":"10.1016/j.ijplas.2025.104331","url":null,"abstract":"<div><div>In this study, laser shock processing (LSP) was used to enhance the mechanical properties of CrCoNi medium-entropy alloys (MEAs) by introducing the gradient microstructures (GS) within the material. Extensive microstructural characterizations confirmed a progressive distribution of nanocrystalline grains, dislocations, and deformation twins along the material's depth. Quantitative measurements of microstructural parameters at varying depths were conducted. Near the surface, the predominant microstructural evolutions were high dislocation density, twins, and grain refinement. At deeper regions, the key behaviors were nanoscale grain refinement and twin collisions. Nanoindentation and micro-pillar compression tests were employed to characterize the hardness distribution and mechanical properties at the microscale. It was found that LSP significantly improved hardness and yield strength. A quantitative relationship between GS and mechanical properties was developed, with theoretical calculations showing good agreement with experimental results. The contributions of different microstructural evolutions to hardness were individually assessed, revealing that multi-stage twins and grain refinement were the primary strengthening factors after one and ten impacts, respectively.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"189 ","pages":"Article 104331"},"PeriodicalIF":9.4,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143806249","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 : 2025-04-08DOI: 10.1016/j.ijplas.2025.104323
X.C. Tang , J.R. Deng , L.Y. Meng , X.H. Yao
The cross-scale rheology of amorphous systems raises a number of problems in the fields of materials science and soft condensed matter physics about their fundamental physical principles. Nevertheless, a clear and concise theoretical framework is still lacking to elucidate the process from microscopic plastic events to the coalescence of shear transformation zones, and subsequently from mesoscopic slip line networks to the emergence of multi-level shear bands. This paper proposes an approach for tracking the activation of plastic events and the growth of plastic zones in amorphous alloys using clustering algorithms. The role of the plastic zone affected zones in the system’s percolation process is described using the Eshelby’s equivalent inclusion theory and the Grady–Kipp momentum diffusion theory, which offers a novel perspective on the mechanism of spontaneous symmetry breaking in amorphous systems with external force. Meanwhile, our research suggests that the cross-scale amorphous rheology is consistent with the fundamental characteristics of Turing patterns to some extent and can be abstracted as a reaction–diffusion system. The stress concentration and stress relaxation caused by plastic zone affected zones function as the activator and the inhibitor in Turing’s framework, respectively. We advocate for additional in-depth research and conceptual innovation to achieve disordered material design in multiple scales.
{"title":"The cross-scale rheology of amorphous system and the resultant Turing-like patterns","authors":"X.C. Tang , J.R. Deng , L.Y. Meng , X.H. Yao","doi":"10.1016/j.ijplas.2025.104323","DOIUrl":"10.1016/j.ijplas.2025.104323","url":null,"abstract":"<div><div>The cross-scale rheology of amorphous systems raises a number of problems in the fields of materials science and soft condensed matter physics about their fundamental physical principles. Nevertheless, a clear and concise theoretical framework is still lacking to elucidate the process from microscopic plastic events to the coalescence of shear transformation zones, and subsequently from mesoscopic slip line networks to the emergence of multi-level shear bands. This paper proposes an approach for tracking the activation of plastic events and the growth of plastic zones in amorphous alloys using clustering algorithms. The role of the plastic zone affected zones in the system’s percolation process is described using the Eshelby’s equivalent inclusion theory and the Grady–Kipp momentum diffusion theory, which offers a novel perspective on the mechanism of spontaneous symmetry breaking in amorphous systems with external force. Meanwhile, our research suggests that the cross-scale amorphous rheology is consistent with the fundamental characteristics of Turing patterns to some extent and can be abstracted as a reaction–diffusion system. The stress concentration and stress relaxation caused by plastic zone affected zones function as the activator and the inhibitor in Turing’s framework, respectively. We advocate for additional in-depth research and conceptual innovation to achieve disordered material design in multiple scales.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"189 ","pages":"Article 104323"},"PeriodicalIF":9.4,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797610","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 : 2025-04-08DOI: 10.1016/j.ijplas.2025.104328
Yoshiteru Aoyagi, Louis Narita Camboulives
In recent years, there has been progress in the development of constitutive models for reproducing the mechanical properties of glassy polymers, but there are limitations to conventional models, such as increased complexity and the number of material parameters. In this study, a new model was proposed to describe the nonlinear viscoelastic-viscoplastic behavior under loading, unloading, and cyclic loading conditions at temperatures below the glass transition temperature. The anelastic strain was considered in addition to elastic strain and plastic strain, which is based on three states: a stable state, a metastable state in tension, and a metastable state in compression. The numerical results obtained with the present model were compared with those obtained with the latest existing model and with the experimental results to investigate the ability to model both viscoelasticity and viscoplasticity. The proposed model stands out for its capacity to predict nonlinear viscoelasticity and viscoplasticity for various loading conditions with only simple thermal activation processes. The 22 material parameters required are fewer than those of recent models used for comparison. This is because the proposed model expresses the viscoelastic phenomena during loading and unloading in a unified manner.
{"title":"Modeling of nonlinear viscoelastic-viscoplastic behavior of glassy polymers based on intramolecular rotation of molecular chains","authors":"Yoshiteru Aoyagi, Louis Narita Camboulives","doi":"10.1016/j.ijplas.2025.104328","DOIUrl":"https://doi.org/10.1016/j.ijplas.2025.104328","url":null,"abstract":"In recent years, there has been progress in the development of constitutive models for reproducing the mechanical properties of glassy polymers, but there are limitations to conventional models, such as increased complexity and the number of material parameters. In this study, a new model was proposed to describe the nonlinear viscoelastic-viscoplastic behavior under loading, unloading, and cyclic loading conditions at temperatures below the glass transition temperature. The anelastic strain was considered in addition to elastic strain and plastic strain, which is based on three states: a stable state, a metastable state in tension, and a metastable state in compression. The numerical results obtained with the present model were compared with those obtained with the latest existing model and with the experimental results to investigate the ability to model both viscoelasticity and viscoplasticity. The proposed model stands out for its capacity to predict nonlinear viscoelasticity and viscoplasticity for various loading conditions with only simple thermal activation processes. The 22 material parameters required are fewer than those of recent models used for comparison. This is because the proposed model expresses the viscoelastic phenomena during loading and unloading in a unified manner.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"183 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797745","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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