Pub Date : 2025-02-06DOI: 10.1016/j.msea.2025.148015
Shouwen Xu , Sining Pan , Zhiyong Li , Shaoxia Li , Xiuli He , Xiangnan Pan
Additive manufacturing (AM) or 3D printing is a promising technology that can easily produce parts or components with complex configuration. IN718 or GH4169 is selected as experimental object, which is an age-hardenable Ni-based (Ni-Cr-Fe) superalloy suitable for AM and can have good plasticity in its as-printed state. Although the strength of as-printed material can be increased by solution aging treatment, the plasticity will be significantly reduced at the same time. Here, we designed, fabricated, heat-treated and machined the specimens, performed a quasi-static tension and a post-mortem analysis for the nickel alloy without and with a solution aging. As-printed and heat-treated specimens show anisotropic tensile behavior on horizontal and vertical orientations. For as-printed specimens, tensile plasticity can be slightly improved with increasing orientation, and the failure type will transit from 45° shearing of Mode-II/III to Mode-I in the core region of fracture surfaces. Due to inter/intra-granular precipitation of solution aging, heat-treated horizontal specimen will change fracture mode to coordinate tensile deformation, making a better ductility for the high-strength nickel alloy of AM.
{"title":"Anisotropic tensile behavior and fracture characteristics of an additively manufactured nickel alloy without and with a heat treatment of solution aging","authors":"Shouwen Xu , Sining Pan , Zhiyong Li , Shaoxia Li , Xiuli He , Xiangnan Pan","doi":"10.1016/j.msea.2025.148015","DOIUrl":"10.1016/j.msea.2025.148015","url":null,"abstract":"<div><div>Additive manufacturing (AM) or 3D printing is a promising technology that can easily produce parts or components with complex configuration. IN718 or GH4169 is selected as experimental object, which is an age-hardenable Ni-based (Ni-Cr-Fe) superalloy suitable for AM and can have good plasticity in its as-printed state. Although the strength of as-printed material can be increased by solution aging treatment, the plasticity will be significantly reduced at the same time. Here, we designed, fabricated, heat-treated and machined the specimens, performed a quasi-static tension and a post-mortem analysis for the nickel alloy without and with a solution aging. As-printed and heat-treated specimens show anisotropic tensile behavior on horizontal and vertical orientations. For as-printed specimens, tensile plasticity can be slightly improved with increasing orientation, and the failure type will transit from 45° shearing of Mode-II/III to Mode-I in the core region of fracture surfaces. Due to inter/intra-granular precipitation of solution aging, heat-treated horizontal specimen will change fracture mode to coordinate tensile deformation, making a better ductility for the high-strength nickel alloy of AM.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 148015"},"PeriodicalIF":6.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377957","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}
Pub Date : 2025-02-05DOI: 10.1016/j.msea.2025.148000
Fatemeh Toghani-Taheri, Farzad Khodabakhshi, Mehdi Malekan, Mahmoud Nili-Ahmadabadi
A Ni49.2Ti50.8 (nitinol) shape-memory alloy was prepared using a vacuum re-melting furnace. The surface of the alloy was modified, and tungsten surface alloying was applied using the friction stir processing (FSP) technique, with varying tool rotational speed as the crucial processing parameter. The aim was to engineer microstructural evolutions and phase transformations in surface-modified and alloyed NiTi materials and assess the developments in mechanical properties. The research focused on the pseudoelastic behavior of processed shape memory materials upon cyclic loading and unloading tensile experiments, depending on microstructural details and alloy design. The electron backscatter diffraction (EBSD) analysis of stirred zones of NiTi and NiTi/W alloys revealed significant grain structural refinement undergoing the operative dynamic recrystallization (DRX) mechanism and the formation of an equiaxed microstructure with an average size of less than 9.6 μm, with a preferred substantial shear orientation majority. The hardness of NiTi alloy increased up to ∼344 Vickers by friction stir modification. Implementing FSP under the rotational speed of 800 rpm and traverse velocity of 50 mm/min yielded the best pseudoelastic properties for the modified alloy up to around 8 % strain, concerning the 10 % strain response of the primary cast alloy before modification. Meanwhile, applying thermal aging at an optimized temperature of 500 °C for 2 h improved the pseudoelastic behavior of the FSP-treated alloy up to ∼20 % strain, compared to the upgraded value of ∼14 % strain for the base alloy after the same post-heat treatment. The micro-mechanisms beyond such evaluation trends in pseudoelastic properties depending on the thermo-mechanical action of FSP were discussed and clarified.
{"title":"Cyclic pseudoelastic behavior of friction stir processed NiTi shape memory alloy: Microstructure and W-alloying","authors":"Fatemeh Toghani-Taheri, Farzad Khodabakhshi, Mehdi Malekan, Mahmoud Nili-Ahmadabadi","doi":"10.1016/j.msea.2025.148000","DOIUrl":"10.1016/j.msea.2025.148000","url":null,"abstract":"<div><div>A Ni<sub>49.2</sub>Ti<sub>50.8</sub> (nitinol) shape-memory alloy was prepared using a vacuum re-melting furnace. The surface of the alloy was modified, and tungsten surface alloying was applied using the friction stir processing (FSP) technique, with varying tool rotational speed as the crucial processing parameter. The aim was to engineer microstructural evolutions and phase transformations in surface-modified and alloyed NiTi materials and assess the developments in mechanical properties. The research focused on the pseudoelastic behavior of processed shape memory materials upon cyclic loading and unloading tensile experiments, depending on microstructural details and alloy design. The electron backscatter diffraction (EBSD) analysis of stirred zones of NiTi and NiTi/W alloys revealed significant grain structural refinement undergoing the operative dynamic recrystallization (DRX) mechanism and the formation of an equiaxed microstructure with an average size of less than 9.6 μm, with a preferred substantial shear orientation majority. The hardness of NiTi alloy increased up to ∼344 Vickers by friction stir modification. Implementing FSP under the rotational speed of 800 rpm and traverse velocity of 50 mm/min yielded the best pseudoelastic properties for the modified alloy up to around 8 % strain, concerning the 10 % strain response of the primary cast alloy before modification. Meanwhile, applying thermal aging at an optimized temperature of 500 °C for 2 h improved the pseudoelastic behavior of the FSP-treated alloy up to ∼20 % strain, compared to the upgraded value of ∼14 % strain for the base alloy after the same post-heat treatment. The micro-mechanisms beyond such evaluation trends in pseudoelastic properties depending on the thermo-mechanical action of FSP were discussed and clarified.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 148000"},"PeriodicalIF":6.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350546","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}
Pub Date : 2025-02-05DOI: 10.1016/j.msea.2025.147999
Yan Zhang , Qizhe Ye , Yinghu Wang , Lijie Qiao , Yu Yan
In this study, we successfully fabricated a medium Mn steel (8Mn-6Al-2Cu-0.6C) with a heterogeneous microstructure by applying single-step warm rolling and intercritical annealing (IA) treatment. Compared to the homogeneous microstructure, the heterogeneous microstructure significantly improved the mechanical properties of the designed steel, reflected by the values of yield strength from 624.3 to 1036.1 MPa, ultimate tensile strength from 812.6 to 1208 MPa, and total elongation from 33.8 % to 54 %. According to quantitative analyses, yield strength increased primarily due to hetero-deformation-induced (HDI) strengthening, which was produced by the extensive geometrically necessary dislocations (GNDs) generated in the soft domain of the inhomogeneous microstructure during deformation. Moreover, HDI strengthening reduced the mechanical mismatch between the soft (austenite) and hard (martensite/ferrite) domains, thus improving phase compatibility. As the strain levels increased, GND accumulations further promoted the occurrence of dynamic strain partitioning between the phases and a sufficient transformation-induced plasticity (TRIP) effect. On the other hand, the heterogeneous austenite with different morphologies and dimensions exhibited various stabilities, leading to a stepwise TRIP effect and the excellent ductility of the steel.
{"title":"Synergistic improvement in the strength and ductility of a medium Mn steel by single-step warm rolling and intercritical annealing","authors":"Yan Zhang , Qizhe Ye , Yinghu Wang , Lijie Qiao , Yu Yan","doi":"10.1016/j.msea.2025.147999","DOIUrl":"10.1016/j.msea.2025.147999","url":null,"abstract":"<div><div>In this study, we successfully fabricated a medium Mn steel (8Mn-6Al-2Cu-0.6C) with a heterogeneous microstructure by applying single-step warm rolling and intercritical annealing (IA) treatment. Compared to the homogeneous microstructure, the heterogeneous microstructure significantly improved the mechanical properties of the designed steel, reflected by the values of yield strength from 624.3 to 1036.1 MPa, ultimate tensile strength from 812.6 to 1208 MPa, and total elongation from 33.8 % to 54 %. According to quantitative analyses, yield strength increased primarily due to hetero-deformation-induced (HDI) strengthening, which was produced by the extensive geometrically necessary dislocations (GNDs) generated in the soft domain of the inhomogeneous microstructure during deformation. Moreover, HDI strengthening reduced the mechanical mismatch between the soft (austenite) and hard (martensite/ferrite) domains, thus improving phase compatibility. As the strain levels increased, GND accumulations further promoted the occurrence of dynamic strain partitioning between the phases and a sufficient transformation-induced plasticity (TRIP) effect. On the other hand, the heterogeneous austenite with different morphologies and dimensions exhibited various stabilities, leading to a stepwise TRIP effect and the excellent ductility of the steel.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147999"},"PeriodicalIF":6.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377282","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}
Pub Date : 2025-02-05DOI: 10.1016/j.msea.2025.147972
Q.W. Tian , J.L. Chen , J.X. Song , M. Wang , S.S. Wu , S.Y. Liang , P.F. Zhang , L.F. Xie , J. Tian , Z. Chen , X.T. Zhong , G. Kou , J.K. Feng , Y.N. Wang , X.W. Cheng
It is highly challenging to achieve a combination of high strength, sufficient ductility, and excellent work hardening rate in face-centered cubic high-entropy alloys under high strain rates. In the study, we demonstrate that the presence of coherent nano-scale L12 precipitates can enhance the dynamic compressive yield strength by at least 57.43 % without compromising the ductility and strain hardening capacity at the strain rate ranging from 1000 to 4000 s−1. The introduction of nano-scale L12 precipitates is not only impede effectively the movement of dislocation on the primary slip plane, but stimulate the dislocation cross slip and multiple slip system. Our finding provides a pathway for the design and preparation of face-centered cubic-based high entropy alloys with outstanding dynamic mechanical properties.
{"title":"Enhanced dynamic mechanical properties of face-centered cubic CoCrFeNi-based high entropy alloy via coherent L12 nanoprecipitates","authors":"Q.W. Tian , J.L. Chen , J.X. Song , M. Wang , S.S. Wu , S.Y. Liang , P.F. Zhang , L.F. Xie , J. Tian , Z. Chen , X.T. Zhong , G. Kou , J.K. Feng , Y.N. Wang , X.W. Cheng","doi":"10.1016/j.msea.2025.147972","DOIUrl":"10.1016/j.msea.2025.147972","url":null,"abstract":"<div><div>It is highly challenging to achieve a combination of high strength, sufficient ductility, and excellent work hardening rate in face-centered cubic high-entropy alloys under high strain rates. In the study, we demonstrate that the presence of coherent nano-scale L1<sub>2</sub> precipitates can enhance the dynamic compressive yield strength by at least 57.43 % without compromising the ductility and strain hardening capacity at the strain rate ranging from 1000 to 4000 s<sup>−1</sup>. The introduction of nano-scale L1<sub>2</sub> precipitates is not only impede effectively the movement of dislocation on the primary slip plane, but stimulate the dislocation cross slip and multiple slip system. Our finding provides a pathway for the design and preparation of face-centered cubic-based high entropy alloys with outstanding dynamic mechanical properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147972"},"PeriodicalIF":6.1,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143704","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}
Pub Date : 2025-02-04DOI: 10.1016/j.msea.2025.147971
Mingdong Wu, Daihong Xiao, Shuo Yuan, Zeyu Li, Yang Huang, Xiao Yin, Juan Wang, Lanping Huang, Wensheng Liu
Heterogeneous grain structures have been demonstrated to effectively balance the strength-ductility trade-off in Al-Zn-Mg-Cu alloys, but studies on their fatigue behaviors remain insufficiently explored. Herein, we examine the impact of bimodal grain structures on the grain boundary precipitate characteristics and the final fatigue crack propagation (FCP) behaviors of T74-tempered Al-Zn-Mg-Cu alloys. Three types of bimodal grain structures are constructed, comprising recrystallized coarse grains (CGs) embedded within non-recrystallized fine grains (FGs) in homogeneous (∼90% CGs), banded (∼50% CGs), and dispersed (∼20% CGs) configurations. Following aging, the recrystallized CGs with high-angle grain boundaries are predominantly associated with coarse grain boundary precipitates (GBPs) and wide precipitation-free zones (PFZs), while the non-recrystallized FGs exhibit finer GBPs and narrower PFZs. Multi-scale analysis of crack propagation behavior reveals that the FG regions have a limited ability to accumulate dislocations, while the CGs provide minimal resistance to crack propagation due to the presence of soft PFZs. Consequently, alloys with dispersed and homogeneous CG distributions demonstrate high fatigue crack growth rates. Interestingly, the interaction between the crack tip and the banded CGs awakens the stress dissipation in CGs, which effectively suppresses the driving force of crack initiation and propagation via significant crack blunting and deflection. Therefore, the alloy with ∼50% banded CGs distributed in FGs exhibits superior resistance to crack propagation compared with the other configurations. These findings highlight that optimizing heterostructure parameters is a promising strategy for enhancing fatigue crack resistance in age-hardened aluminum alloys.
{"title":"Revealing the role of heterogeneous microstructure on fatigue crack propagation behaviors in T74 Al-Zn-Mg-Cu alloys","authors":"Mingdong Wu, Daihong Xiao, Shuo Yuan, Zeyu Li, Yang Huang, Xiao Yin, Juan Wang, Lanping Huang, Wensheng Liu","doi":"10.1016/j.msea.2025.147971","DOIUrl":"10.1016/j.msea.2025.147971","url":null,"abstract":"<div><div>Heterogeneous grain structures have been demonstrated to effectively balance the strength-ductility trade-off in Al-Zn-Mg-Cu alloys, but studies on their fatigue behaviors remain insufficiently explored. Herein, we examine the impact of bimodal grain structures on the grain boundary precipitate characteristics and the final fatigue crack propagation (FCP) behaviors of T74-tempered Al-Zn-Mg-Cu alloys. Three types of bimodal grain structures are constructed, comprising recrystallized coarse grains (CGs) embedded within non-recrystallized fine grains (FGs) in homogeneous (∼90% CGs), banded (∼50% CGs), and dispersed (∼20% CGs) configurations. Following aging, the recrystallized CGs with high-angle grain boundaries are predominantly associated with coarse grain boundary precipitates (GBPs) and wide precipitation-free zones (PFZs), while the non-recrystallized FGs exhibit finer GBPs and narrower PFZs. Multi-scale analysis of crack propagation behavior reveals that the FG regions have a limited ability to accumulate dislocations, while the CGs provide minimal resistance to crack propagation due to the presence of soft PFZs. Consequently, alloys with dispersed and homogeneous CG distributions demonstrate high fatigue crack growth rates. Interestingly, the interaction between the crack tip and the banded CGs awakens the stress dissipation in CGs, which effectively suppresses the driving force of crack initiation and propagation via significant crack blunting and deflection. Therefore, the alloy with ∼50% banded CGs distributed in FGs exhibits superior resistance to crack propagation compared with the other configurations. These findings highlight that optimizing heterostructure parameters is a promising strategy for enhancing fatigue crack resistance in age-hardened aluminum alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"926 ","pages":"Article 147971"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134232","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}
Pub Date : 2025-02-04DOI: 10.1016/j.msea.2025.147990
Shujing Lu , Yang Li , Shuying Zhen , Donghai Yu , Liang Zhang , Rong Chen , Yanli Wang , Shilei Li
The fabrication of thin-walled components from titanium alloys like TA15 presents challenges due to their high reactivity, resistance to deformation, and low thermal conductivity. Traditional manufacturing methods often struggle with these complexities, making Laser Powder Bed Fusion (L-PBF) a promising alternative due to its advanced design flexibility and processing capabilities. This study explores the effects of L-PBF process parameters—laser power, scanning speed, inter-layer offset angle, and island size—on the microstructure, defects, residual stress, and mechanical properties of TA15 titanium alloy. We varied the laser power from 250 to 310 W and the scanning speed from 1000 to 1400 mm/s, analyzing their impact on sample density, defect formation, and overall mechanical performance. Our findings highlight that an optimal energy density of 55.6 J/mm³, achieved with a laser power of 280 W and a scanning speed of 1200 mm/s, results in superior forming quality. Microstructural analysis shows the predominance of fine, needle-like α′ martensite with high dislocation density. Increased energy density correlates with smaller martensite plate widths and higher residual stresses. Additionally, a 67° inter-layer offset and reduced island sizes help minimize warpage and enhance surface quality. This research offers critical insights for optimizing L-PBF parameters, aiming to improve the performance and durability of TA15 titanium alloy components in aerospace applications.
{"title":"Influence of process parameters on the microstructures, residual stresses and mechanical properties of TA15 titanium alloy fabricated by L-PBF","authors":"Shujing Lu , Yang Li , Shuying Zhen , Donghai Yu , Liang Zhang , Rong Chen , Yanli Wang , Shilei Li","doi":"10.1016/j.msea.2025.147990","DOIUrl":"10.1016/j.msea.2025.147990","url":null,"abstract":"<div><div>The fabrication of thin-walled components from titanium alloys like TA15 presents challenges due to their high reactivity, resistance to deformation, and low thermal conductivity. Traditional manufacturing methods often struggle with these complexities, making Laser Powder Bed Fusion (L-PBF) a promising alternative due to its advanced design flexibility and processing capabilities. This study explores the effects of L-PBF process parameters—laser power, scanning speed, inter-layer offset angle, and island size—on the microstructure, defects, residual stress, and mechanical properties of TA15 titanium alloy. We varied the laser power from 250 to 310 W and the scanning speed from 1000 to 1400 mm/s, analyzing their impact on sample density, defect formation, and overall mechanical performance. Our findings highlight that an optimal energy density of 55.6 J/mm³, achieved with a laser power of 280 W and a scanning speed of 1200 mm/s, results in superior forming quality. Microstructural analysis shows the predominance of fine, needle-like α′ martensite with high dislocation density. Increased energy density correlates with smaller martensite plate widths and higher residual stresses. Additionally, a 67° inter-layer offset and reduced island sizes help minimize warpage and enhance surface quality. This research offers critical insights for optimizing L-PBF parameters, aiming to improve the performance and durability of TA15 titanium alloy components in aerospace applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147990"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143349048","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}
Pub Date : 2025-02-04DOI: 10.1016/j.msea.2025.147995
S. Benmabrouk , B. Vieille , E. Hug
The influence of the orientation (parallel/normal to the build direction) on the fracture of a Laser Powder Bed Fusion Ni-20 wt%Cr is investigated. Significantly different behaviors are demonstrated, with the most pronounced intergranular fracture. The large fracture anisotropy observed is mainly driven by the grain size and the grain boundary nature.
{"title":"On the role of the microstructure on the anisotropic fracture behavior of a Laser Powder Bed Fusion Ni-20 wt%Cr alloy","authors":"S. Benmabrouk , B. Vieille , E. Hug","doi":"10.1016/j.msea.2025.147995","DOIUrl":"10.1016/j.msea.2025.147995","url":null,"abstract":"<div><div>The influence of the orientation (parallel/normal to the build direction) on the fracture of a Laser Powder Bed Fusion Ni-20 wt%Cr is investigated. Significantly different behaviors are demonstrated, with the most pronounced intergranular fracture. The large fracture anisotropy observed is mainly driven by the grain size and the grain boundary nature.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147995"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143308216","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}
Pub Date : 2025-02-04DOI: 10.1016/j.msea.2025.147927
Xiaying Ma , Kerong Ren , Rong Chen , Shun Li , Jiaqiang Wu
The micro-structure, dynamical compression property and spallation behaviour were investigated in TiZrHf refractory multi-principal element alloy (RMPEA) with a single Hexagonal Close-Packed (HCP) phase, considering the spatial heterogeneity between central and peripheral regions. Based on a single-stage gas gun, plate impact experiments were driven with impact velocities ranging from 327 to 710 m·s−1, and results showing the Hugoniot data were c0 = 3.55 km·s−1 and s = 0.97, while the spall strength σspall increased from 1.92 GPa to 2.01 GPa. The shock-response behaviour was accurately predicted using the equation of state derived from a cold-energy mixture model. Microstructural analysis of recovered samples revealed that voids nucleated preferentially at grain boundaries, especially at triple junctions of twin boundaries. As the impact velocity increased, the damage mode shifted from intergranular to a mix of intergranular and intragranular, eventually becoming predominantly intragranular. Additionally, under impact loading, multiple cross-slip and <c+a> type pyramidal dislocations were activated, forming dislocation loops and walls. Moreover, interactions between dislocations and grain boundaries promoted stacking faults (SF) activation, twin formation and HCP-to-Face-Centered Cubic (FCC) phase transformation. Additionally, the self-activated twinning mechanism facilitated the formation of low-energy twins under high strain rates, as stacking fault energy (SFE) became dominant over short-range order (SRO). Comparative data on various MPEAs showed a negative correlation between the yield strength to spall strength ratio (σy/σspall) and valence electron concentration (VEC).
{"title":"Shock compression and spallation of TiZrHf refractory multi-principal element alloy","authors":"Xiaying Ma , Kerong Ren , Rong Chen , Shun Li , Jiaqiang Wu","doi":"10.1016/j.msea.2025.147927","DOIUrl":"10.1016/j.msea.2025.147927","url":null,"abstract":"<div><div>The micro-structure, dynamical compression property and spallation behaviour were investigated in TiZrHf refractory multi-principal element alloy (RMPEA) with a single Hexagonal Close-Packed (HCP) phase, considering the spatial heterogeneity between central and peripheral regions. Based on a single-stage gas gun, plate impact experiments were driven with impact velocities ranging from 327 to 710 m·s<sup>−1</sup>, and results showing the Hugoniot data were <em>c</em><sub>0</sub> = 3.55 km·s<sup>−1</sup> and <em>s</em> = 0.97, while the spall strength <em>σ</em><sub>spall</sub> increased from 1.92 GPa to 2.01 GPa. The shock-response behaviour was accurately predicted using the equation of state derived from a cold-energy mixture model. Microstructural analysis of recovered samples revealed that voids nucleated preferentially at grain boundaries, especially at triple junctions of twin boundaries. As the impact velocity increased, the damage mode shifted from intergranular to a mix of intergranular and intragranular, eventually becoming predominantly intragranular. Additionally, under impact loading, multiple cross-slip and <c+a> type pyramidal dislocations were activated, forming dislocation loops and walls. Moreover, interactions between dislocations and grain boundaries promoted stacking faults (SF) activation, twin formation and HCP-to-Face-Centered Cubic (FCC) phase transformation. Additionally, the self-activated twinning mechanism facilitated the formation of low-energy twins under high strain rates, as stacking fault energy (SFE) became dominant over short-range order (SRO). Comparative data on various MPEAs showed a negative correlation between the yield strength to spall strength ratio (<em>σ</em><sub>y</sub>/<em>σ</em><sub>spall</sub>) and valence electron concentration (<em>VEC</em>).</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147927"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143706","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}
Pub Date : 2025-02-04DOI: 10.1016/j.msea.2025.147970
Pengfei Wu , Lijun Zhan , Kefu Gan , Dingshun Yan , Yong Zhang , Zhiming Li
In this work, interstitial carbon has been employed to further enhance the mechanical and anti-corrosion properties of a metastable quinary Fe40Mn10Co20Cr20Ni10 (at. %) high-entropy alloy (HEA). Both the C-free and C-doped (0.5 at. %) HEAs exhibit a face-centered cubic (FCC) single-phase structure after annealing. Upon tensile deformation, martensitic transformation prevails in the C-free alloy with the formation of hexagonal closed packed (HCP) phase, whereas dislocation slip and twinning are the dominant deformation modes in the C-doped HEA. Such shift of deformation mechanisms can be attributed to the carbon induced increase of stacking fault energy (SFE) (from ∼10 to ∼15 mJ/m2). Simultaneous increases of strength and ductility are achieved in this HEA system by carbon alloying. Carbon-induced interstitial solid solution strengthening effect contributes to the increased stress level, whereas the promoted twinning behavior contributes to the enhanced strain hardening ability. Besides, electrochemical corrosion analysis demonstrates that interstitial carbon reduces the active current density and accelerates the passivation process of the HEA upon immersion in 0.1M H2SO4 solution, contributing to the enhanced corrosion resistance. The findings offer insights into the design of strong, ductile and corrosion-resistant alloys.
{"title":"Interstitials enable enhanced mechanical and anti-corrosion properties of a non-equiatomic quinary high-entropy alloy","authors":"Pengfei Wu , Lijun Zhan , Kefu Gan , Dingshun Yan , Yong Zhang , Zhiming Li","doi":"10.1016/j.msea.2025.147970","DOIUrl":"10.1016/j.msea.2025.147970","url":null,"abstract":"<div><div>In this work, interstitial carbon has been employed to further enhance the mechanical and anti-corrosion properties of a metastable quinary Fe<sub>40</sub>Mn<sub>10</sub>Co<sub>20</sub>Cr<sub>20</sub>Ni<sub>10</sub> (at. %) high-entropy alloy (HEA). Both the C-free and C-doped (0.5 at. %) HEAs exhibit a face-centered cubic (FCC) single-phase structure after annealing. Upon tensile deformation, martensitic transformation prevails in the C-free alloy with the formation of hexagonal closed packed (HCP) phase, whereas dislocation slip and twinning are the dominant deformation modes in the C-doped HEA. Such shift of deformation mechanisms can be attributed to the carbon induced increase of stacking fault energy (SFE) (from ∼10 to ∼15 mJ/m<sup>2</sup>). Simultaneous increases of strength and ductility are achieved in this HEA system by carbon alloying. Carbon-induced interstitial solid solution strengthening effect contributes to the increased stress level, whereas the promoted twinning behavior contributes to the enhanced strain hardening ability. Besides, electrochemical corrosion analysis demonstrates that interstitial carbon reduces the active current density and accelerates the passivation process of the HEA upon immersion in 0.1M H<sub>2</sub>SO<sub>4</sub> solution, contributing to the enhanced corrosion resistance. The findings offer insights into the design of strong, ductile and corrosion-resistant alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147970"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143142827","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}
In-situ neutron diffraction studies of changes in the dislocation density and dislocation rearrangement have been performed during tensile deformation of Al-1.14Mn-0.16Si-0.14Fe (mass%) alloy, which were homogenized at different conditions (sample-A: 350 °C for 60 h and sample-B: 500 °C for 4 h) for controlling size and number density of dispersoids. The sample homogenized at 350 °C shows finer size and higher volume fraction of dispersoids than those of the sample homogenized at 500 °C. An increase rate of the dislocation density and the yield stress of the sample homogenized at 350 °C are higher due to more effective short-range interactions controlled by dislocation pinning by dispersoids. The larger number of finer dispersoids leads to higher applied stress, proportional to the yield stress, required for dislocations to pass these obstacles in order to facilitate further plastic deformation. The presence of dispersoids leads to an inhibition of the dislocation cell wall formation induced by large dislocation accumulation during the deformation. The inhibition of the cell formation is indicated by a trend change of the dislocation rearrangement parameter from an increasing trend to a decreasing trend is observed at ∼0.06 true strain for the sample-B and at ∼0.1 true strain for the sample-A. The finer and larger number density of dispersoids caused longer delay in the formation of dislocation cell walls.
{"title":"Effect of fine dispersoids on dislocation density and dislocation rearrangement of Al-Mn alloy during tensile deformation","authors":"Pramote Thirathipviwat , Takuma Kotake , Taketo Suzuki , Makoto Hasegawa , Katsushi Matsumoto , Shigeo Sato","doi":"10.1016/j.msea.2025.147997","DOIUrl":"10.1016/j.msea.2025.147997","url":null,"abstract":"<div><div>In-situ neutron diffraction studies of changes in the dislocation density and dislocation rearrangement have been performed during tensile deformation of Al-1.14Mn-0.16Si-0.14Fe (mass%) alloy, which were homogenized at different conditions (sample-A: 350 °C for 60 h and sample-B: 500 °C for 4 h) for controlling size and number density of dispersoids. The sample homogenized at 350 °C shows finer size and higher volume fraction of dispersoids than those of the sample homogenized at 500 °C. An increase rate of the dislocation density and the yield stress of the sample homogenized at 350 °C are higher due to more effective short-range interactions controlled by dislocation pinning by dispersoids. The larger number of finer dispersoids leads to higher applied stress, proportional to the yield stress, required for dislocations to pass these obstacles in order to facilitate further plastic deformation. The presence of dispersoids leads to an inhibition of the dislocation cell wall formation induced by large dislocation accumulation during the deformation. The inhibition of the cell formation is indicated by a trend change of the dislocation rearrangement parameter from an increasing trend to a decreasing trend is observed at ∼0.06 true strain for the sample-B and at ∼0.1 true strain for the sample-A. The finer and larger number density of dispersoids caused longer delay in the formation of dislocation cell walls.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147997"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350544","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}
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