Materials Science and Engineering: A最新文献

Microstructure and very high cycle fatigue characteristics of powder bed fused – laser beam (PBF-LB) scandium-free Al-Mg-Zr alloy

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-07 DOI: 10.1016/j.msea.2025.148177

Shawkat I. Shakil , Wiktor Bednarczyk , Marta Gajewska , Zaynab Mahbooba , Ankit Saharan , Andrea Tridello , Davide S. Paolino , Meysam Haghshenas

This study investigates the microstructure and very high cycle fatigue (VHCF) behavior of a powder bed fusion–laser beam (PBF-LB) processed scandium-free Al-Mg-Zr alloy (commercially known as EOS Al5X1) through advanced microstructural characterization, defect analysis, ultrasonic fatigue testing, and detailed fractographic examination. The analysis focuses on defect-driven crack initiation, particularly process-induced volumetric defects such as pores, lack of fusion, and non-metallic (oxide) inclusions. Scanning electron microscopy-based fractography reveals that in the VHCF regime, where the number of cycles to failure (N_f) > 10⁷ cycles, fatigue crack initiation predominantly shifts toward the subsurface or interior of the specimen. In multiple cases, process-induced volumetric defects facilitated crack initiation, resulting in characteristic 'fisheye' fracture morphologies. The chemical composition of these critical defects was also analyzed in detail. The study highlights the significant impact of process-induced volumetric defects on fracture morphology and examines the influence of defect size and location on VHCF performance. These findings provide deeper insight into the interplay between processing defects and crack nucleation, underscoring the necessity of advanced defect characterization to better understand VHCF life variability.

{"title":"Microstructure and very high cycle fatigue characteristics of powder bed fused – laser beam (PBF-LB) scandium-free Al-Mg-Zr alloy","authors":"Shawkat I. Shakil , Wiktor Bednarczyk , Marta Gajewska , Zaynab Mahbooba , Ankit Saharan , Andrea Tridello , Davide S. Paolino , Meysam Haghshenas","doi":"10.1016/j.msea.2025.148177","DOIUrl":"10.1016/j.msea.2025.148177","url":null,"abstract":"<div><div>This study investigates the microstructure and very high cycle fatigue (VHCF) behavior of a powder bed fusion–laser beam (PBF-LB) processed scandium-free Al-Mg-Zr alloy (commercially known as EOS Al5X1) through advanced microstructural characterization, defect analysis, ultrasonic fatigue testing, and detailed fractographic examination. The analysis focuses on defect-driven crack initiation, particularly process-induced volumetric defects such as pores, lack of fusion, and non-metallic (oxide) inclusions. Scanning electron microscopy-based fractography reveals that in the VHCF regime, where the number of cycles to failure (N<sub>f</sub>) > 10<sup>7</sup> cycles, fatigue crack initiation predominantly shifts toward the subsurface or interior of the specimen. In multiple cases, process-induced volumetric defects facilitated crack initiation, resulting in characteristic 'fisheye' fracture morphologies. The chemical composition of these critical defects was also analyzed in detail. The study highlights the significant impact of process-induced volumetric defects on fracture morphology and examines the influence of defect size and location on VHCF performance. These findings provide deeper insight into the interplay between processing defects and crack nucleation, underscoring the necessity of advanced defect characterization to better understand VHCF life variability.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148177"},"PeriodicalIF":6.1,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mechanism of trace oxygen promoting ductility in as-cast Ti-6Al-4V alloys

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-06 DOI: 10.1016/j.msea.2025.148176

Yuqing Song , Guodong Wang , Ying Zhang , Mingxiang Zhu , Sisi Xie , Hongchao Kou

In this paper, the effect of oxygen content in the range of 0.15–0.44 wt% on the tensile properties at room temperature of cast Ti-6Al-4V alloy was studied, and the effect mechanism of oxygen on the tensile deformation behavior was discussed. The results show that with the increase in oxygen content, the strength of the alloy improves, while the elongation increases first and then decreases. Oxygen dissolving in α phase leads to obvious change of lattice constant c/a ratio. The activation of prismatic slips in α phase facilitates the migration of oxygen atoms from octahedral site to hexahedral site to reduce stacking fault energy. The improvement of strength and the decreasement of elongation are attributed to the solid solution strengthening mechanism, while the abnormal highest elongation of the alloy with 0.22 wt% oxygen is due to the oxygen atoms moving into the hexahedral site.

引用次数: 0

Simultaneously increasing the strength and ductility of a Ni-Co-based superalloy via dual-heterostructure design 通过双异质结构设计同时提高镍钴基超合金的强度和延展性

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-06 DOI: 10.1016/j.msea.2025.148174

J. Wang , W. Dai , H.R. Lu , W.L. Su , Q. Cheng , X.C. Lu , B. Gan , H.J. Yang , X.L. Ma , Y.T. Zhu , C.X. Huang

Ni-Co-based superalloys are recognized as promising materials for the turbine discs of next-generation aero-engines, but the internal strength-ductility trade-off limits their applications. Here, we present a dual heterostructured Ni-Co-based superalloy characterized by harmonic grain heterostructure comprising fine grains and ultrafine grains, which is accompanied by bimodal-sized γ′ precipitates. The superalloy exhibits an outstanding strength-ductility synergy, with high yield strength (∼1.5 GPa) and ultimate tensile strength (∼1.8 GPa), concurrent with high uniform elongation (∼21 %), which is much higher than its solution and aging counterparts and superior to most superalloys. The excellent tensile properties primarily originate from its distinctive heterostructure and work hardening mechanism. The inhomogeneous plastic deformation leads to a high density of geometrically necessary dislocations pile-up near the hetero-zone boundaries, yielding so-called hetero-deformation-induced hardening. Besides, the bimodal-sized γ′ precipitates effectively impede dislocations slip to improve work hardening capacity. Additionally, stacking faults, Lomer-Cottrell locks and twins also contributed to the strain hardening. These findings suggest that the dual heterostructure design strategy is promising to improve the strength-ductility synergy in Ni-Co-based alloys.

{"title":"Simultaneously increasing the strength and ductility of a Ni-Co-based superalloy via dual-heterostructure design","authors":"J. Wang , W. Dai , H.R. Lu , W.L. Su , Q. Cheng , X.C. Lu , B. Gan , H.J. Yang , X.L. Ma , Y.T. Zhu , C.X. Huang","doi":"10.1016/j.msea.2025.148174","DOIUrl":"10.1016/j.msea.2025.148174","url":null,"abstract":"<div><div>Ni-Co-based superalloys are recognized as promising materials for the turbine discs of next-generation aero-engines, but the internal strength-ductility trade-off limits their applications. Here, we present a dual heterostructured Ni-Co-based superalloy characterized by harmonic grain heterostructure comprising fine grains and ultrafine grains, which is accompanied by bimodal-sized γ′ precipitates. The superalloy exhibits an outstanding strength-ductility synergy, with high yield strength (∼1.5 GPa) and ultimate tensile strength (∼1.8 GPa), concurrent with high uniform elongation (∼21 %), which is much higher than its solution and aging counterparts and superior to most superalloys. The excellent tensile properties primarily originate from its distinctive heterostructure and work hardening mechanism. The inhomogeneous plastic deformation leads to a high density of geometrically necessary dislocations pile-up near the hetero-zone boundaries, yielding so-called hetero-deformation-induced hardening. Besides, the bimodal-sized γ′ precipitates effectively impede dislocations slip to improve work hardening capacity. Additionally, stacking faults, Lomer-Cottrell locks and twins also contributed to the strain hardening. These findings suggest that the dual heterostructure design strategy is promising to improve the strength-ductility synergy in Ni-Co-based alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148174"},"PeriodicalIF":6.1,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dynamic compression of dendritic high-entropy alloy Al0.5CoCrFeNi with various microstructures: Experiments and constitutive modeling

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-05 DOI: 10.1016/j.msea.2025.148117

C.K. Wan , J.C. Yuan , L.X. Li , Y. Cai , Y.W. Shi , Q.C. Liu , L. Lu , N.B. Zhang , S.N. Luo

The mechanical properties and microstructural evolution of as-cast and heat-treated dendritic dual phase high-entropy alloy (HEA)

{Al}_{0.5} CoCrFeNi

are investigated to provides valuable insights into their plastic deformation, particularly under varying strain rates and temperatures. The as-cast

{Al}_{0.5} CoCrFeNi

alloy, consisting of face-centered cubic (FCC) dendritic and body-centered cubic (BCC) interdendritic phases, is compared to a heat-treated variant, which contains additional needle-shaped BCC precipitates within the dendritic domains. Uniaxial compression tests are conducted across a strain rate range of 10⁻³ to 2000

s^{- 1}

and a temperature range of 173 to 673 K for both types of the alloys. The results show that the yield strength of the alloys increases with higher strain rates or lower temperatures. The heat-treated alloy, benefiting from the precipitate strengthening of additional needle-shaped precipitates, exhibits higher yield strength than the as-cast alloy. Dislocation slip and kink bands dominate the plastic deformation firstly. As the true strain increases, nano twins are observed. Cryogenic temperatures promote more nano twins with different variants. Additionally, different plastic deformation partitioning behaviors between the FCC and BCC phases are observed due to the microstructure differences between the two types of alloys. Furthermore, the Johnson-Cook-Cowper Symonds (JC-CS) constitutive models are developed and successfully describe the plastic flow of both types of the alloys over a wide range of strain rates and temperatures, providing a valuable tool for future research and applications.

{"title":"Dynamic compression of dendritic high-entropy alloy Al0.5CoCrFeNi with various microstructures: Experiments and constitutive modeling","authors":"C.K. Wan , J.C. Yuan , L.X. Li , Y. Cai , Y.W. Shi , Q.C. Liu , L. Lu , N.B. Zhang , S.N. Luo","doi":"10.1016/j.msea.2025.148117","DOIUrl":"10.1016/j.msea.2025.148117","url":null,"abstract":"<div><div>The mechanical properties and microstructural evolution of as-cast and heat-treated dendritic dual phase high-entropy alloy (HEA) <span><math><mrow><msub><mrow><mi>Al</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>5</mn></mrow></msub><mi>CoCrFeNi</mi></mrow></math></span> are investigated to provides valuable insights into their plastic deformation, particularly under varying strain rates and temperatures. The as-cast <span><math><mrow><msub><mrow><mi>Al</mi></mrow><mrow><mn>0</mn><mo>.</mo><mn>5</mn></mrow></msub><mi>CoCrFeNi</mi></mrow></math></span> alloy, consisting of face-centered cubic (FCC) dendritic and body-centered cubic (BCC) interdendritic phases, is compared to a heat-treated variant, which contains additional needle-shaped BCC precipitates within the dendritic domains. Uniaxial compression tests are conducted across a strain rate range of 10<sup>−3</sup> to 2000 <span><math><msup><mrow><mi>s</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span> and a temperature range of 173 to 673 K for both types of the alloys. The results show that the yield strength of the alloys increases with higher strain rates or lower temperatures. The heat-treated alloy, benefiting from the precipitate strengthening of additional needle-shaped precipitates, exhibits higher yield strength than the as-cast alloy. Dislocation slip and kink bands dominate the plastic deformation firstly. As the true strain increases, nano twins are observed. Cryogenic temperatures promote more nano twins with different variants. Additionally, different plastic deformation partitioning behaviors between the FCC and BCC phases are observed due to the microstructure differences between the two types of alloys. Furthermore, the Johnson-Cook-Cowper Symonds (JC-CS) constitutive models are developed and successfully describe the plastic flow of both types of the alloys over a wide range of strain rates and temperatures, providing a valuable tool for future research and applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148117"},"PeriodicalIF":6.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the strength-plasticity enhancement mechanism of the SiCp/Fe symmetric gradient structure and alloying in the high-particle-content layer

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148140

Wen-quan Li , Zheng-yu Zhong , Ning-zhi Zheng , Kai-yao Wang , Ying Guo , Chao Zhang

The construction of heterogeneous structures is an effective method to achieve a favorable balance between material strength and ductility. By controlling the silicon carbide (SiCp) particle content, Fe-based layered composites with a symmetric gradient structure were prepared using spark plasma sintering (SPS) and subjected to hot rolling to investigate the microstructural evolution and mechanical performance of each layer. The results show that the gradient distribution of SiCp content leads to different grain sizes across the layers. The formation of an amorphous layer between SiCp and Fe, as well as FeSiO₃ crystalline products, promoted strong bonding between the two. The gradient distribution of SiCp content resulted in a symmetric gradient in Vickers hardness values across the material. Compared with pure Fe, homogeneous 3 % SiCp/Fe, and 10 % SiCp/Fe composites, the SiCp/Fe symmetric gradient structure exhibited higher hardness without a significant reduction in plasticity. After hot rolling, the yield strength of the SiCp/Fe symmetric gradient structure reached 912.45 MPa, with an elongation of 7.67 %. In this study, the strength and plasticity of the symmetric gradient structure were enhanced by 178.10 % and 56.53 %, respectively, compared with the Fe-8Cr-4.5Ni structure prepared by SPS. This demonstrated the synergistic enhancement effect of the symmetric gradient design on strength and plasticity. Additionally, due to the high localized stresses during the hot rolling process, SiCp in the 10 % SiCp/Fe layer was decomposed and reacted with the Fe matrix to form Fe-C and Fe-Si compounds. The ultrafine grains in this layer also contributed to the high strength of material.

{"title":"Study on the strength-plasticity enhancement mechanism of the SiCp/Fe symmetric gradient structure and alloying in the high-particle-content layer","authors":"Wen-quan Li , Zheng-yu Zhong , Ning-zhi Zheng , Kai-yao Wang , Ying Guo , Chao Zhang","doi":"10.1016/j.msea.2025.148140","DOIUrl":"10.1016/j.msea.2025.148140","url":null,"abstract":"<div><div>The construction of heterogeneous structures is an effective method to achieve a favorable balance between material strength and ductility. By controlling the silicon carbide (SiCp) particle content, Fe-based layered composites with a symmetric gradient structure were prepared using spark plasma sintering (SPS) and subjected to hot rolling to investigate the microstructural evolution and mechanical performance of each layer. The results show that the gradient distribution of SiCp content leads to different grain sizes across the layers. The formation of an amorphous layer between SiCp and Fe, as well as FeSiO<sub>3</sub> crystalline products, promoted strong bonding between the two. The gradient distribution of SiCp content resulted in a symmetric gradient in Vickers hardness values across the material. Compared with pure Fe, homogeneous 3 % SiCp/Fe, and 10 % SiCp/Fe composites, the SiCp/Fe symmetric gradient structure exhibited higher hardness without a significant reduction in plasticity. After hot rolling, the yield strength of the SiCp/Fe symmetric gradient structure reached 912.45 MPa, with an elongation of 7.67 %. In this study, the strength and plasticity of the symmetric gradient structure were enhanced by 178.10 % and 56.53 %, respectively, compared with the Fe-8Cr-4.5Ni structure prepared by SPS. This demonstrated the synergistic enhancement effect of the symmetric gradient design on strength and plasticity. Additionally, due to the high localized stresses during the hot rolling process, SiCp in the 10 % SiCp/Fe layer was decomposed and reacted with the Fe matrix to form Fe-C and Fe-Si compounds. The ultrafine grains in this layer also contributed to the high strength of material.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148140"},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deformation mechanisms of hexagonal close-packed-multi-principal element alloys (HCP-MPEAs) with equiaxed structures

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148143

S.J. Liang , T. Yoshino , R. Matusmoto , R. Sahara , Y. Toda , S. Matsunaga , G. Miyamoto , Y. Yamabe-Mitarai

The successful fabrication of multi-principal element alloys (MPEAs) with stable single-phase face-centered cubic (FCC) and body-centered cubic (BCC) structures has enabled numerous studies to highlight their excellent mechanical properties and distinct deformation mechanisms. However, the solid-solution strengthening (SSS) and deformation mechanisms of hexagonal close-packed (HCP)-MPEAs remain poorly understood due to the lack of stable single-phase HCP alloys. In this study, equiaxed single-phase HCP structures were successfully developed in Ti₄₅Zr₄₅Al₁₀, Ti₃₄Zr₃₃Hf₃₃, Ti₃₅Zr₃₀Hf₃₀Al₅, and Ti₃₀Zr₃₀Hf₃₀Al₁₀ alloy systems through precise thermomechanical processing and subsequent heat treatment. Ti₄₅Zr₄₅Al₁₀, Ti₃₀Zr₃₀Hf₃₀Al₁₀, and Ti₃₅Zr₃₀Hf₃₀Al₅ exhibited high 0.2 % proof strength from 25 °C to 600 °C. The 0.2 % proof stress increased with both mixing entropy (

Δ S_{m i x}

) and average atomic radius misfit (δ), aligning with calculations that indicate a stronger SSS effect at higher δ values. Density functional theory calculations further reveal that Al plays a crucial role in enhancing SSS. Deformation was primarily governed by (10

\overline{1}

0) prismatic slip. The low activation volume and high-stress exponent of these alloys at 600 °C suggest that minor obstacles, such as clusters or short-range order, hinder dislocation motion, thereby contributing to significant SSS.

{"title":"Deformation mechanisms of hexagonal close-packed-multi-principal element alloys (HCP-MPEAs) with equiaxed structures","authors":"S.J. Liang , T. Yoshino , R. Matusmoto , R. Sahara , Y. Toda , S. Matsunaga , G. Miyamoto , Y. Yamabe-Mitarai","doi":"10.1016/j.msea.2025.148143","DOIUrl":"10.1016/j.msea.2025.148143","url":null,"abstract":"<div><div>The successful fabrication of multi-principal element alloys (MPEAs) with stable single-phase face-centered cubic (FCC) and body-centered cubic (BCC) structures has enabled numerous studies to highlight their excellent mechanical properties and distinct deformation mechanisms. However, the solid-solution strengthening (SSS) and deformation mechanisms of hexagonal close-packed (HCP)-MPEAs remain poorly understood due to the lack of stable single-phase HCP alloys. In this study, equiaxed single-phase HCP structures were successfully developed in Ti<sub>45</sub>Zr<sub>45</sub>Al<sub>10</sub>, Ti<sub>34</sub>Zr<sub>33</sub>Hf<sub>33</sub>, Ti<sub>35</sub>Zr<sub>30</sub>Hf<sub>30</sub>Al<sub>5</sub>, and Ti<sub>30</sub>Zr<sub>30</sub>Hf<sub>30</sub>Al<sub>10</sub> alloy systems through precise thermomechanical processing and subsequent heat treatment. Ti<sub>45</sub>Zr<sub>45</sub>Al<sub>10</sub>, Ti<sub>30</sub>Zr<sub>30</sub>Hf<sub>30</sub>Al<sub>10</sub>, and Ti<sub>35</sub>Zr<sub>30</sub>Hf<sub>30</sub>Al<sub>5</sub> exhibited high 0.2 % proof strength from 25 °C to 600 °C. The 0.2 % proof stress increased with both mixing entropy (<span><math><mrow><mo>Δ</mo><msub><mi>S</mi><mrow><mi>m</mi><mi>i</mi><mi>x</mi></mrow></msub></mrow></math></span>) and average atomic radius misfit (δ), aligning with calculations that indicate a stronger SSS effect at higher δ values. Density functional theory calculations further reveal that Al plays a crucial role in enhancing SSS. Deformation was primarily governed by (10 <span><math><mrow><mover><mn>1</mn><mo>‾</mo></mover></mrow></math></span> 0) prismatic slip. The low activation volume and high-stress exponent of these alloys at 600 °C suggest that minor obstacles, such as clusters or short-range order, hinder dislocation motion, thereby contributing to significant SSS.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"929 ","pages":""},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143535358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling the flow stress and work hardening behavior of an Al-Cu-Li alloy using a microstructure sensitive superposition law

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148137

Purnima Bharti, Jyoti Ranjan Sahoo, Salunke Rohan Ravindra, Ripudaman Singh, Sumeet Mishra

A comprehensive framework for analyzing the flow stress and work hardening behavior of an Al-Cu-Li alloy as a function of precipitation state is developed in the current work. The backbone of the flow stress model is the usage of microstructure sensitive superposition exponents for quantifying the overall strengthening contribution from the different obstacles (precipitates, solutes, forest dislocations) in the microstructure. Analytical calculations based on microstructure-based inputs reveal that superposition exponents have a complex dependence on the precipitation state, which needs to be accounted for in the model for a consistent prediction of the flow curves. The simplifying practice of linear superposition of strengthening mechanisms leads to a large discrepancy between experiments and simulations. The usage of microstructure sensitive flow stress model also has implications on the macroscopic work hardening rate in the sense that precipitates have a direct effect on the global work hardening rate apart from the conventional wisdom of precipitates affecting the global work hardening rate indirectly by altering the dislocation recovery rate. With respect to the indirect effect on work hardening, a strong increase in dynamic recovery propensity was observed with ageing time, which is manifested in terms of decrease in uniform elongation with ageing time. The insights developed from the current work reveal that when the ratio of dynamic recovery rate and dislocation storage rate reaches a threshold value of ∼0.8, the material is highly susceptible to necking. The threshold value was validated for different formable grade Al alloys.

{"title":"Modeling the flow stress and work hardening behavior of an Al-Cu-Li alloy using a microstructure sensitive superposition law","authors":"Purnima Bharti, Jyoti Ranjan Sahoo, Salunke Rohan Ravindra, Ripudaman Singh, Sumeet Mishra","doi":"10.1016/j.msea.2025.148137","DOIUrl":"10.1016/j.msea.2025.148137","url":null,"abstract":"<div><div>A comprehensive framework for analyzing the flow stress and work hardening behavior of an Al-Cu-Li alloy as a function of precipitation state is developed in the current work. The backbone of the flow stress model is the usage of microstructure sensitive superposition exponents for quantifying the overall strengthening contribution from the different obstacles (precipitates, solutes, forest dislocations) in the microstructure. Analytical calculations based on microstructure-based inputs reveal that superposition exponents have a complex dependence on the precipitation state, which needs to be accounted for in the model for a consistent prediction of the flow curves. The simplifying practice of linear superposition of strengthening mechanisms leads to a large discrepancy between experiments and simulations. The usage of microstructure sensitive flow stress model also has implications on the macroscopic work hardening rate in the sense that precipitates have a direct effect on the global work hardening rate apart from the conventional wisdom of precipitates affecting the global work hardening rate indirectly by altering the dislocation recovery rate. With respect to the indirect effect on work hardening, a strong increase in dynamic recovery propensity was observed with ageing time, which is manifested in terms of decrease in uniform elongation with ageing time. The insights developed from the current work reveal that when the ratio of dynamic recovery rate and dislocation storage rate reaches a threshold value of ∼0.8, the material is highly susceptible to necking. The threshold value was validated for different formable grade Al alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"929 ","pages":"Article 148137"},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of interlayer mechanical heterogeneity on deformation behavior and mechanical properties of hybrid-manufactured 316L stainless steel produced by selective laser melting

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148161

Zihao Jiang , Lei Zhou , Tingyi Lin , Yingfei Guo , Nanping Yue , Pingwei Xu , Qinghua Song , Xiang Li , Lieyong Pei , Yu Liang

Remelting at the bonding interface induces the formation of a transition layer characterized by finer grains. The optimized hybrid-manufactured 316L stainless steel (SS) samples exhibit superior strength-ductility synergy. During deformation, the mechanical heterogeneity between the selective laser melting (SLM) layer and the solution-treated (ST) layer induces the production of additional strain hardening in the melt pool (MP) interior and the interfacial strain gradient. The strength enhancement primarily arises from the cellular substructure entangled with dislocations and the back stress induced by hetero-deformation induced (HDI) strengthening. These factors collectively contribute to the synergistic enhancement of strength-ductility in the hybrid-manufacturing 316L SS specimens. In addition, the HDI strengthening effect is affected by the volume fraction of the SLM layer. As this fraction increases, the capability of interfacial coordination deformation gradually diminishes. When the geometrically necessary dislocations (GNDs) at the bonding interface are insufficient to effectively accommodate the strain mismatch arising during deformation between the SLM and ST layers, it results in failure of the bonding interface. These findings reveal both deformation behavior and strengthening mechanisms in hybrid-manufactured 316L SS with mechanical heterogeneity.

{"title":"Effect of interlayer mechanical heterogeneity on deformation behavior and mechanical properties of hybrid-manufactured 316L stainless steel produced by selective laser melting","authors":"Zihao Jiang , Lei Zhou , Tingyi Lin , Yingfei Guo , Nanping Yue , Pingwei Xu , Qinghua Song , Xiang Li , Lieyong Pei , Yu Liang","doi":"10.1016/j.msea.2025.148161","DOIUrl":"10.1016/j.msea.2025.148161","url":null,"abstract":"<div><div>Remelting at the bonding interface induces the formation of a transition layer characterized by finer grains. The optimized hybrid-manufactured 316L stainless steel (SS) samples exhibit superior strength-ductility synergy. During deformation, the mechanical heterogeneity between the selective laser melting (SLM) layer and the solution-treated (ST) layer induces the production of additional strain hardening in the melt pool (MP) interior and the interfacial strain gradient. The strength enhancement primarily arises from the cellular substructure entangled with dislocations and the back stress induced by hetero-deformation induced (HDI) strengthening. These factors collectively contribute to the synergistic enhancement of strength-ductility in the hybrid-manufacturing 316L SS specimens. In addition, the HDI strengthening effect is affected by the volume fraction of the SLM layer. As this fraction increases, the capability of interfacial coordination deformation gradually diminishes. When the geometrically necessary dislocations (GNDs) at the bonding interface are insufficient to effectively accommodate the strain mismatch arising during deformation between the SLM and ST layers, it results in failure of the bonding interface. These findings reveal both deformation behavior and strengthening mechanisms in hybrid-manufactured 316L SS with mechanical heterogeneity.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148161"},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Crack-tip gradient microstructure: Formation and influence on impact toughness behavior of low-carbon ferritic steel

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148166

Khilesh Kumar Bhandari , Arka Mandal , Md. Basiruddin Sk , Arnab Karani , Devang Gandhi , Arghya Deb , Debalay Chakrabarti

The present study proposes a novel approach to extend the service life of structural components with pre-existing cracks by utilizing targeted heat treatment to selectively tailor the crack-tip microstructure, thereby enhancing mechanical properties. Charpy V-notched (CVN) specimens were subjected to tensile pre-straining and annealing to form distinct notch-root microstructures. Pre-straining induced heterogeneous plastic deformation, forming a kidney-shaped plastic zone (r_p∗). Subsequent annealing led to the formation of gradient ferrite grains at the notch-tip primarily through recrystallization and strain-induced boundary migration (SIBM). Lower pre-strains exhibited a steep gradient in ferrite grain size (GS) upon annealing, whereas higher pre-strain levels revealed a gradual transition from fine to coarse ferrite grains in all directions surrounding the notch. Strain above a critical threshold induced complete recrystallization, forming fine, strain-free ferrite grains near the notch-root, while strain below this level caused structural restoration via abnormal grain coarsening by SIBM. Additionally, statistical analysis indicated a power relation between GS and strain in the modified zone upon annealing at 650 °C for 3 h. Superior impact toughness resulted from a gradual ferrite GS gradient, owing to fine grains resisting crack propagation, while poor impact toughness arose from a steep gradient with coarse ferrite grains within the active zone facilitating cleavage crack initiation. In summary, this investigation explores the role of distinct localized gradient microstructures at the crack-tip on the impact toughness behavior of low-carbon ferritic steel.

{"title":"Crack-tip gradient microstructure: Formation and influence on impact toughness behavior of low-carbon ferritic steel","authors":"Khilesh Kumar Bhandari , Arka Mandal , Md. Basiruddin Sk , Arnab Karani , Devang Gandhi , Arghya Deb , Debalay Chakrabarti","doi":"10.1016/j.msea.2025.148166","DOIUrl":"10.1016/j.msea.2025.148166","url":null,"abstract":"<div><div>The present study proposes a novel approach to extend the service life of structural components with pre-existing cracks by utilizing targeted heat treatment to selectively tailor the crack-tip microstructure, thereby enhancing mechanical properties. Charpy V-notched (CVN) specimens were subjected to tensile pre-straining and annealing to form distinct notch-root microstructures. Pre-straining induced heterogeneous plastic deformation, forming a kidney-shaped plastic zone (<em>r</em><sub><em>p</em></sub><em>∗</em>). Subsequent annealing led to the formation of gradient ferrite grains at the notch-tip primarily through recrystallization and strain-induced boundary migration (SIBM). Lower pre-strains exhibited a steep gradient in ferrite grain size (GS) upon annealing, whereas higher pre-strain levels revealed a gradual transition from fine to coarse ferrite grains in all directions surrounding the notch. Strain above a critical threshold induced complete recrystallization, forming fine, strain-free ferrite grains near the notch-root, while strain below this level caused structural restoration via abnormal grain coarsening by SIBM. Additionally, statistical analysis indicated a power relation between GS and strain in the modified zone upon annealing at 650 °C for 3 h. Superior impact toughness resulted from a gradual ferrite GS gradient, owing to fine grains resisting crack propagation, while poor impact toughness arose from a steep gradient with coarse ferrite grains within the active zone facilitating cleavage crack initiation. In summary, this investigation explores the role of distinct localized gradient microstructures at the crack-tip on the impact toughness behavior of low-carbon ferritic steel.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148166"},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Anisotropies in microstructure and properties of Si3N4/BN composite ceramics: Synergistic effect of bimodal texture

IF 6.1 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Science and Engineering: A

Pub Date : 2025-03-04 DOI: 10.1016/j.msea.2025.148162

Yunwei Shi , Qianglong He , Aiyang Wang , Hao Wang , Weimin Wang , Zhengyi Fu

Textured Si₃N₄/BN composite ceramics are prepared via combination of PHIP sintering and gas pressure sintering. The mechanical properties of composite ceramics gradually decrease with the increase of BN content. However, the bimodal texture of Si₃N₄/BN composite ceramics exhibits a synergistic effect on the anisotropy of thermal and mechanical properties. When the BN content is 20 vol%, The anisotropy of fracture toughness along different testing direction reaches 51.0 %. By the proper regulation of the bimodal texture, Si₃N₄/BN composite ceramics could simply realize a high thermal conductivity (99.2 W m⁻¹ k⁻¹) and thermal anisotropy (2.1) at low sintering temperature (1800 °C) for short preparation period (4 h). This bimodal texture breaks through the inhibition of the high thermal conductivity of Si₃N₄-based ceramics by the amorphous phase of low thermal conductivities. Thus, this new material designs have great advantages in large-scale preparation and directional heat dissipation in the next-generation electric devices.

{"title":"Anisotropies in microstructure and properties of Si3N4/BN composite ceramics: Synergistic effect of bimodal texture","authors":"Yunwei Shi , Qianglong He , Aiyang Wang , Hao Wang , Weimin Wang , Zhengyi Fu","doi":"10.1016/j.msea.2025.148162","DOIUrl":"10.1016/j.msea.2025.148162","url":null,"abstract":"<div><div>Textured Si<sub>3</sub>N<sub>4</sub>/BN composite ceramics are prepared via combination of PHIP sintering and gas pressure sintering. The mechanical properties of composite ceramics gradually decrease with the increase of BN content. However, the bimodal texture of Si<sub>3</sub>N<sub>4</sub>/BN composite ceramics exhibits a synergistic effect on the anisotropy of thermal and mechanical properties. When the BN content is 20 vol%, The anisotropy of fracture toughness along different testing direction reaches 51.0 %. By the proper regulation of the bimodal texture, Si<sub>3</sub>N<sub>4</sub>/BN composite ceramics could simply realize a high thermal conductivity (99.2 W m<sup>−1</sup> k<sup>−1</sup>) and thermal anisotropy (2.1) at low sintering temperature (1800 °C) for short preparation period (4 h). This bimodal texture breaks through the inhibition of the high thermal conductivity of Si<sub>3</sub>N<sub>4</sub>-based ceramics by the amorphous phase of low thermal conductivities. Thus, this new material designs have great advantages in large-scale preparation and directional heat dissipation in the next-generation electric devices.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"930 ","pages":"Article 148162"},"PeriodicalIF":6.1,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0