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.2025.147927
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}
Pub Date : 2025-02-03DOI: 10.1016/j.msea.2025.147978
H. Zhang, X.Y. Xue, M.J. Xue, J.S. Li, M.J. Lai
We have demonstrated that 1 at.% C-doping enhances both the strength-ductility synergy and strain-hardenability of the metastable face-centered cubic (fcc) single-phase Fe50Mn30Cr10Si10 high-entropy alloy (HEA), which exhibits transformation-induced plasticity (TRIP) effect. These enhancements result from interstitial solid solution hardening as well as a beneficial increase in fcc phase stability and stacking fault energy (SFE) due to C-doping. The increased phase stability and SFE activate deformation twinning and the formation of 9R structures, while preserving the TRIP effect. Our findings underscore C-doping as a promising strategy for designing novel high-performance metastable fcc single-phase HEAs.
{"title":"Concurrently improved strength-ductility synergy and strain-hardenability in metastable face-centered cubic high-entropy alloys through C-doping","authors":"H. Zhang, X.Y. Xue, M.J. Xue, J.S. Li, M.J. Lai","doi":"10.1016/j.msea.2025.147978","DOIUrl":"10.1016/j.msea.2025.147978","url":null,"abstract":"<div><div>We have demonstrated that 1 at.% C-doping enhances both the strength-ductility synergy and strain-hardenability of the metastable face-centered cubic (fcc) single-phase Fe<sub>50</sub>Mn<sub>30</sub>Cr<sub>10</sub>Si<sub>10</sub> high-entropy alloy (HEA), which exhibits transformation-induced plasticity (TRIP) effect. These enhancements result from interstitial solid solution hardening as well as a beneficial increase in fcc phase stability and stacking fault energy (SFE) due to C-doping. The increased phase stability and SFE activate deformation twinning and the formation of 9R structures, while preserving the TRIP effect. Our findings underscore C-doping as a promising strategy for designing novel high-performance metastable fcc single-phase HEAs.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"926 ","pages":"Article 147978"},"PeriodicalIF":6.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134182","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 : 2025-02-02DOI: 10.1016/j.msea.2025.147969
Yu Zhang , Lipeng Ding , Yaru Ning , Yi Su , Chenglin Wang , Zhihong Jia , Linzhong Zhuang
The effects of the individual and co-addition of Mn and Zn elements on the precipitation of Al3(Sc, Zr) dispersoids, recrystallization resistance and mechanical properties of Al-Mg-Sc-Zr alloy were studied using scanning electron microscopy, transmission electron microscope, first-principles calculation and tensile testing. The results show that although Mn and Zn could not penetrate in the Al3(Sc, Zr) dispersoids, these two elements can shift the L12-Al3(Sc, Zr) solvus towards higher Sc concentrations and thus inhibit the precipitation of Al3(Sc, Zr) dispersoids. Except for the Al3(Sc, Zr), high density of Al(Fe, Mn)Si dispersoids are formed in the Mn-added alloys, provides additional strengthening effect. The recrystallization resistance is slightly improved after Mn or Zn addition owing to the formation multiple dispersoids or the sluggish grain boundary migration induced by solute Zn atoms. Both of the Mn and Zn addition can improve the strength but decrease the elongation of the Al-Mg-Sc-Zr alloy, the effect of Mn in increasing the strength is much stronger than Zn, and the combined Mn, Zn addition does not show clear advantage compared with individual Zn addition, suggesting superior advantage of the Mn addition in this alloy. The main reason is due to the synergistic enhancement of the dispersion strengthening of the Al(Fe, Mn)Si and Al3(Sc, Zr) dispersoids. This result provides in insight in the development new low-Mg content Al-Mg-Sc-Zr alloys with high properties.
{"title":"Influence of Mn and Zn addition on the formation of dispersoids and mechanical properties of Al-Mg-Sc-Zr alloys","authors":"Yu Zhang , Lipeng Ding , Yaru Ning , Yi Su , Chenglin Wang , Zhihong Jia , Linzhong Zhuang","doi":"10.1016/j.msea.2025.147969","DOIUrl":"10.1016/j.msea.2025.147969","url":null,"abstract":"<div><div>The effects of the individual and co-addition of Mn and Zn elements on the precipitation of Al<sub>3</sub>(Sc, Zr) dispersoids, recrystallization resistance and mechanical properties of Al-Mg-Sc-Zr alloy were studied using scanning electron microscopy, transmission electron microscope, first-principles calculation and tensile testing. The results show that although Mn and Zn could not penetrate in the Al<sub>3</sub>(Sc, Zr) dispersoids, these two elements can shift the L1<sub>2</sub>-Al<sub>3</sub>(Sc, Zr) solvus towards higher Sc concentrations and thus inhibit the precipitation of Al<sub>3</sub>(Sc, Zr) dispersoids. Except for the Al<sub>3</sub>(Sc, Zr), high density of Al(Fe, Mn)Si dispersoids are formed in the Mn-added alloys, provides additional strengthening effect. The recrystallization resistance is slightly improved after Mn or Zn addition owing to the formation multiple dispersoids or the sluggish grain boundary migration induced by solute Zn atoms. Both of the Mn and Zn addition can improve the strength but decrease the elongation of the Al-Mg-Sc-Zr alloy, the effect of Mn in increasing the strength is much stronger than Zn, and the combined Mn, Zn addition does not show clear advantage compared with individual Zn addition, suggesting superior advantage of the Mn addition in this alloy. The main reason is due to the synergistic enhancement of the dispersion strengthening of the Al(Fe, Mn)Si and Al<sub>3</sub>(Sc, Zr) dispersoids. This result provides in insight in the development new low-Mg content Al-Mg-Sc-Zr alloys with high properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"926 ","pages":"Article 147969"},"PeriodicalIF":6.1,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143134159","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 : 2025-02-02DOI: 10.1016/j.msea.2025.147984
Bin Wu , Jingjing Liang , Yanhong Yang , Jinguo Li , Xiaofeng Sun
Additive manufacturing (AM) superalloys is the materials research frontier full of challenges nowadays. The present paper investigates the tensile deformation behavior of a novel superalloy specifically developed for additive manufacturing. Two kinds of sample state are used: the as-built (directly obtained from AM) and the heat-treated (endured aging treatment at 870 °C for 16 h). During tensile tests at 650 °C and 700 °C, two different strain rates were adopted. It was found that the strength and plasticity of the heat-treated alloy were significantly improved compared with that of the as-built. Furthermore, the as-built alloy exhibited significant serrated plastic flow, the types of serrations varied with the applied strain rate. The serrations were effectively suppressed through aging treatment. To reveal the underlying mechanisms, the microstructures of both as-built and heat-treated alloy were characterized and analyzed. The formation of serrations were ascribed to dynamic strain aging (DSA). This work provides implications for tailoring the microstructure in additively manufactured components to improve properties, thus supporting the practical application of additive manufacturing superalloys.
{"title":"The influences of aging treatment on the serrated flow of a superalloy specially designed for additive manufacturing","authors":"Bin Wu , Jingjing Liang , Yanhong Yang , Jinguo Li , Xiaofeng Sun","doi":"10.1016/j.msea.2025.147984","DOIUrl":"10.1016/j.msea.2025.147984","url":null,"abstract":"<div><div>Additive manufacturing (AM) superalloys is the materials research frontier full of challenges nowadays. The present paper investigates the tensile deformation behavior of a novel superalloy specifically developed for additive manufacturing. Two kinds of sample state are used: the as-built (directly obtained from AM) and the heat-treated (endured aging treatment at 870 °C for 16 h). During tensile tests at 650 °C and 700 °C, two different strain rates were adopted. It was found that the strength and plasticity of the heat-treated alloy were significantly improved compared with that of the as-built. Furthermore, the as-built alloy exhibited significant serrated plastic flow, the types of serrations varied with the applied strain rate. The serrations were effectively suppressed through aging treatment. To reveal the underlying mechanisms, the microstructures of both as-built and heat-treated alloy were characterized and analyzed. The formation of serrations were ascribed to dynamic strain aging (DSA). This work provides implications for tailoring the microstructure in additively manufactured components to improve properties, thus supporting the practical application of additive manufacturing superalloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"927 ","pages":"Article 147984"},"PeriodicalIF":6.1,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143142829","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 : 2025-02-01DOI: 10.1016/j.msea.2024.147659
Jie Cheng , Yujie Ma , Xiaotian Wang , Liang Cheng , Yaoyao Hu , Tairan Xu , Zhenhua Cao
In this study, Cu40Mn30Ni30 (Ti0) and Cu38Mn28.5Ni28.5Ti5 (Ti5) medium-entropy alloys (MEAs) were designed, and the influence of 5 at.% Ti addition on the microstructure and mechanical properties of the MEAs was investigated. The results indicated that the addition of Ti promoted the formation of Ni3Ti-rich hexagonal close-packed (hcp) precipitates, leading to significant grain refinement in the Ti5 MEA. The yield strength, tensile strength and elongation of Ti5-A750 MEA achieved 586 ± 17 MPa, 893 ± 18 MPa and 7.7 ± 0.4 %, respectively, showing a superior combination of high strength and ductility compared to the Ti0-A750 MEA and other traditional high-strength Cu alloys. The improvement of mechanical properties for Ti5-A750 MEA was mainly attributed to the synergistic strengthening mechanisms of grain refinement strengthening and precipitation strengthening resulting from the Ni3Ti-rich hcp precipitates. This synergistic strengthening strategy provides new ideas for designing novel high strength and ductility Cu alloys.
{"title":"Grain refinement and precipitation synergistic strengthening in CuMnNiTix medium-entropy alloys","authors":"Jie Cheng , Yujie Ma , Xiaotian Wang , Liang Cheng , Yaoyao Hu , Tairan Xu , Zhenhua Cao","doi":"10.1016/j.msea.2024.147659","DOIUrl":"10.1016/j.msea.2024.147659","url":null,"abstract":"<div><div>In this study, Cu<sub>40</sub>Mn<sub>30</sub>Ni<sub>30</sub> (Ti0) and Cu<sub>38</sub>Mn<sub>28.5</sub>Ni<sub>28.5</sub>Ti<sub>5</sub> (Ti5) medium-entropy alloys (MEAs) were designed, and the influence of 5 at.% Ti addition on the microstructure and mechanical properties of the MEAs was investigated. The results indicated that the addition of Ti promoted the formation of Ni<sub>3</sub>Ti-rich hexagonal close-packed (hcp) precipitates, leading to significant grain refinement in the Ti5 MEA. The yield strength, tensile strength and elongation of Ti5-A750 MEA achieved 586 ± 17 MPa, 893 ± 18 MPa and 7.7 ± 0.4 %, respectively, showing a superior combination of high strength and ductility compared to the Ti0-A750 MEA and other traditional high-strength Cu alloys. The improvement of mechanical properties for Ti5-A750 MEA was mainly attributed to the synergistic strengthening mechanisms of grain refinement strengthening and precipitation strengthening resulting from the Ni<sub>3</sub>Ti-rich hcp precipitates. This synergistic strengthening strategy provides new ideas for designing novel high strength and ductility Cu alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"922 ","pages":"Article 147659"},"PeriodicalIF":6.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099154","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 : 2025-02-01DOI: 10.1016/j.msea.2024.147622
Han Wang, Peng Zhang, ChuanJie Wang, Qiang Zhu, Gang Chen
Understanding and regulating flow stress is crucial for producing high-performance metal thin sheets. Uniaxial tensile tests on Cu-Zn thin sheet metal reveal that the grain size at the inflection point of the size effect on flow stress (SEFS) increases with higher Zn content. This study investigates the intrinsic mechanisms affecting the SEFS, with a focus on how Zn content, grain size, and free surface influence deformation mechanism transitions in face-centered cubic metal thin sheets. Increasing Zn content reduces stacking fault energy, promotes the transition from dislocation wavy slip to planar slip and deformation twinning, increases geometrically necessary dislocation density, and mitigates SEFS. The relationship between the critical stress and strain for the onset of planar slip and deformation twinning and the square root of the grain size deviates from linearity, highlighting the size effect on the deformation mechanisms transition in metal thin sheets. This study identifies the size effects on deformation mechanisms and elucidates their underlying mechanisms. It provides new insights into controlling SEFS in metal thin sheets and lays a foundation for the design of high-performance metal thin sheets.
{"title":"Investigation of the size effect on flow stress and deformation mechanism in Cu-Zn thin sheets","authors":"Han Wang, Peng Zhang, ChuanJie Wang, Qiang Zhu, Gang Chen","doi":"10.1016/j.msea.2024.147622","DOIUrl":"10.1016/j.msea.2024.147622","url":null,"abstract":"<div><div>Understanding and regulating flow stress is crucial for producing high-performance metal thin sheets. Uniaxial tensile tests on Cu-Zn thin sheet metal reveal that the grain size at the inflection point of the size effect on flow stress (SEFS) increases with higher Zn content. This study investigates the intrinsic mechanisms affecting the SEFS, with a focus on how Zn content, grain size, and free surface influence deformation mechanism transitions in face-centered cubic metal thin sheets. Increasing Zn content reduces stacking fault energy, promotes the transition from dislocation wavy slip to planar slip and deformation twinning, increases geometrically necessary dislocation density, and mitigates SEFS. The relationship between the critical stress and strain for the onset of planar slip and deformation twinning and the square root of the grain size deviates from linearity, highlighting the size effect on the deformation mechanisms transition in metal thin sheets. This study identifies the size effects on deformation mechanisms and elucidates their underlying mechanisms. It provides new insights into controlling SEFS in metal thin sheets and lays a foundation for the design of high-performance metal thin sheets.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"922 ","pages":"Article 147622"},"PeriodicalIF":6.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103260","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 : 2025-02-01DOI: 10.1016/j.msea.2024.147647
Heziqi Liu , Lianyong Xu , Kangda Hao , Yongdian Han , Lei Zhao , Wenjing Ren
Recently, laser-arc hybrid additive manufacturing (LAHAM) has emerged as a transformative method for producing lightweight aluminum alloys, valued for its advantageous surface quality and mechanical properties. In this study, the effect of various laser modes on macro morphology, defect formation, microstructure evolution, and mechanical properties of Al-Cu alloy were investigated. At a laser power threshold of 1.5 kW, the transition from conduction mode to keyhole mode was observed. When the keyhole formed, the molten metal exhibited enhanced fluidity, resulting in smoother surfaces and more uniform spreading. As laser power increased, although hydrogen-induced pores (HIP) were notably reduced, the keyhole-induced pores (KIP) began to appear. During subsequent depositions, the intense reheating effects from laser facilitated a transformation from reticular eutectics (RE) along grain boundaries to granular eutectics (GE). Additionally, recrystallization and formation of Σ3 coincidence site lattice (CSL) boundaries were restricted due to the reduced residual stress caused by moderating cooling rates, alleviating stress concentration near pores during deformation. Therefore, optimal results were achieved in conduction mode at a laser power of 1 kW, achieving highest tensile strengths of 269.5 MPa and 260.1 MPa, and elongations of 19.6 % and 13.8 % in horizontal and vertical directions, respectively.
{"title":"Optimizing microstructure and minimizing defects in laser-arc hybrid additive manufacturing of Al-Cu alloy: The role of laser mode","authors":"Heziqi Liu , Lianyong Xu , Kangda Hao , Yongdian Han , Lei Zhao , Wenjing Ren","doi":"10.1016/j.msea.2024.147647","DOIUrl":"10.1016/j.msea.2024.147647","url":null,"abstract":"<div><div>Recently, laser-arc hybrid additive manufacturing (LAHAM) has emerged as a transformative method for producing lightweight aluminum alloys, valued for its advantageous surface quality and mechanical properties. In this study, the effect of various laser modes on macro morphology, defect formation, microstructure evolution, and mechanical properties of Al-Cu alloy were investigated. At a laser power threshold of 1.5 kW, the transition from conduction mode to keyhole mode was observed. When the keyhole formed, the molten metal exhibited enhanced fluidity, resulting in smoother surfaces and more uniform spreading. As laser power increased, although hydrogen-induced pores (HIP) were notably reduced, the keyhole-induced pores (KIP) began to appear. During subsequent depositions, the intense reheating effects from laser facilitated a transformation from reticular eutectics (RE) along grain boundaries to granular eutectics (GE). Additionally, recrystallization and formation of Σ3 coincidence site lattice (CSL) boundaries were restricted due to the reduced residual stress caused by moderating cooling rates, alleviating stress concentration near pores during deformation. Therefore, optimal results were achieved in conduction mode at a laser power of 1 kW, achieving highest tensile strengths of 269.5 MPa and 260.1 MPa, and elongations of 19.6 % and 13.8 % in horizontal and vertical directions, respectively.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"922 ","pages":"Article 147647"},"PeriodicalIF":6.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103266","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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