Pub Date : 2025-11-19DOI: 10.1016/j.actamat.2025.121742
Jianan Chen , Chang Liu , Gang Chen , Wei Cai , Xiaozhou Liao , Jin Zou , Lin Zhang , Mingli Qin , Xuanhui Qu
Additive manufacturing (AM) has the potential to revolutionize metal fabrication by enabling the creation of complex structures. However, the intrinsic high thermal stresses induced by cyclic rapid heating-and-cooling during AM often causes defects in thermal-stress-sensitive metals, hindering their printability. Conventional methods including alloying can eliminate defects and improve the printability, but often lead to deterioration in high-temperature performance. Here, we design an easily printable Nb-3W-2Mo-1Zr-0.1O alloy with exceptional high-temperature properties. The unique microstructure of our alloy, featured nanoscale deformable ZrO2 precipitates and subgrains, effectively mitigates thermal stresses and eliminates defects during laser-based powder bed fusion, and pins grain boundary movements during high-temperature deformation. This endows our alloy with mechanical performance comparable to commercial wrought alloys, but a sevenfold improvement in duration of work hardening showing superior high-temperature softening resistance, making it ideal for next-generation high-temperature structural applications. Our approach paves the way for manufacturing printable and high-performance thermal-stress-sensitive alloys.
{"title":"A printable Nb-based alloy with remarkable high-temperature softening resistance","authors":"Jianan Chen , Chang Liu , Gang Chen , Wei Cai , Xiaozhou Liao , Jin Zou , Lin Zhang , Mingli Qin , Xuanhui Qu","doi":"10.1016/j.actamat.2025.121742","DOIUrl":"10.1016/j.actamat.2025.121742","url":null,"abstract":"<div><div>Additive manufacturing (AM) has the potential to revolutionize metal fabrication by enabling the creation of complex structures. However, the intrinsic high thermal stresses induced by cyclic rapid heating-and-cooling during AM often causes defects in thermal-stress-sensitive metals, hindering their printability. Conventional methods including alloying can eliminate defects and improve the printability, but often lead to deterioration in high-temperature performance. Here, we design an easily printable Nb-3W-2Mo-1Zr-0.1O alloy with exceptional high-temperature properties. The unique microstructure of our alloy, featured nanoscale deformable ZrO<sub>2</sub> precipitates and subgrains, effectively mitigates thermal stresses and eliminates defects during laser-based powder bed fusion, and pins grain boundary movements during high-temperature deformation. This endows our alloy with mechanical performance comparable to commercial wrought alloys, but a sevenfold improvement in duration of work hardening showing superior high-temperature softening resistance, making it ideal for next-generation high-temperature structural applications. Our approach paves the way for manufacturing printable and high-performance thermal-stress-sensitive alloys.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121742"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.actamat.2025.121744
Zheng Liu , Kaixin Sun , Huhu Su , Bin Miao , Fucheng Wang , Kai Yao , Yingjie Ma , Hao Wang , Zhenbo Zhang , Shenbao Jin , Rui Yang , En Ma , Shijian Zheng
Planar slip localizes plastic strains, usually resulting in low uniform ductility (< 2 % elongation) in high-strength titanium (Ti) alloys. Here, we report a precipitate-tailoring strategy to delocalize the planar slip strain, achieving unprecedented tensile ductility without early softening at gigapascal (GPa)-level strength. In a β-Ti alloy (Ti-3Al-6V-6Fe-2Zr, wt. %) fabricated with additive manufacturing (AM), the high Fe content promotes dense ω precipitates that instigate planar slip. Subsequent heat-treatment introduces α precipitates, through which the transmitting slip generates <a> and sluggish <c+a> dislocations, with the latter enhancing both strain hardening and flow resistance. The optimized alloy exhibits remarkable tensile properties: a yield strength of ∼1055 MPa with ∼17 % uniform elongation and ∼30 % total elongation, doubling the ductility of comparable-strength AM Ti alloys. Further refinement of α precipitates achieves an ultrahigh yield strength of ∼1600 MPa (the highest value among AM Ti alloys) while retaining ∼5 % elongation. Our microstructural design is applicable to other planar-slip dominated alloys in enabling unprecedented strength-ductility.
{"title":"Precipitate-tailored planar slip delivers unprecedented ductility in high-strength β-titanium alloys","authors":"Zheng Liu , Kaixin Sun , Huhu Su , Bin Miao , Fucheng Wang , Kai Yao , Yingjie Ma , Hao Wang , Zhenbo Zhang , Shenbao Jin , Rui Yang , En Ma , Shijian Zheng","doi":"10.1016/j.actamat.2025.121744","DOIUrl":"10.1016/j.actamat.2025.121744","url":null,"abstract":"<div><div>Planar slip localizes plastic strains, usually resulting in low uniform ductility (< 2 % elongation) in high-strength titanium (Ti) alloys. Here, we report a precipitate-tailoring strategy to delocalize the planar slip strain, achieving unprecedented tensile ductility without early softening at gigapascal (GPa)-level strength. In a β-Ti alloy (Ti-3Al-6V-6Fe-2Zr, wt. %) fabricated with additive manufacturing (AM), the high Fe content promotes dense ω precipitates that instigate planar slip. Subsequent heat-treatment introduces α precipitates, through which the transmitting slip generates <<strong><em>a</em><em>></em></strong> and sluggish <<strong><em>c</em></strong>+<strong><em>a</em></strong>> dislocations, with the latter enhancing both strain hardening and flow resistance. The optimized alloy exhibits remarkable tensile properties: a yield strength of ∼1055 MPa with ∼17 % uniform elongation and ∼30 % total elongation, doubling the ductility of comparable-strength AM Ti alloys. Further refinement of α precipitates achieves an ultrahigh yield strength of ∼1600 MPa (the highest value among AM Ti alloys) while retaining ∼5 % elongation. Our microstructural design is applicable to other planar-slip dominated alloys in enabling unprecedented strength-ductility.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"304 ","pages":"Article 121744"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.actamat.2025.121747
L.F. Kultz Unti , L.S. Aota , E.S.N. Lopes , G.G. Ribamar , N. Schell , J.P. Oliveira , B. Gault , J.A. Avila , A.L. Jardini , K.D. Zilnyk
High solidification rates and in situ heat treatments are commonly found in additive manufacturing (AM) of steels, resulting in a complex and far-from-equilibrium microstructure. Therefore, standard post-processing heat treatments commonly applied to wrought steels can favor the occurrence of different phenomena and can change the phase transformation sequence, due to the unique microstructure obtained by powder bed fusion – laser beam (PBF-LB). This work reports the microstructural evolution of 15-5 precipitation hardening (PH) stainless steel manufactured by PBF-LB during direct aging heat treatments at 621 °C (AMS H1150 standard condition), a route used to increase fracture toughness due to the martensite reversion and precipitates coarsening. The reversion of martensite into a Ni-rich austenite, predicted by kinetic calculations, was confirmed by high-energy X-ray diffraction (HE-XRD), being preferentially nucleated close to the copper-rich precipitates (CRPs), which can act as a preferential nucleation site. CRPs presented an oval shape, as confirmed by electronic microscopy (SEM and TEM) and atom probe tomography (APT). Fast Fourier transform (FFT) analysis of high-resolution TEM (HR-TEM) images suggests CRPs still present the metastable untwined 3R-type structure after 8 h, rather than the most stable FCC structure. The presence of retained austenite, inherent to PBF-LB-processed PH steels, affects the CRPs evolution in different phases, and the CRPs themselves act as nucleation sites for Nb(C,N) secondary precipitation. These findings emphasize the necessity of microstructure-oriented heat treatment routes to unlock the full potential of additively manufactured PH stainless steels.
{"title":"Microstructural evolution in high-temperature direct aging on PBF-LB 15-5PH stainless steel","authors":"L.F. Kultz Unti , L.S. Aota , E.S.N. Lopes , G.G. Ribamar , N. Schell , J.P. Oliveira , B. Gault , J.A. Avila , A.L. Jardini , K.D. Zilnyk","doi":"10.1016/j.actamat.2025.121747","DOIUrl":"10.1016/j.actamat.2025.121747","url":null,"abstract":"<div><div>High solidification rates and in situ heat treatments are commonly found in additive manufacturing (AM) of steels, resulting in a complex and far-from-equilibrium microstructure. Therefore, standard post-processing heat treatments commonly applied to wrought steels can favor the occurrence of different phenomena and can change the phase transformation sequence, due to the unique microstructure obtained by powder bed fusion – laser beam (PBF-LB). This work reports the microstructural evolution of 15-5 precipitation hardening (PH) stainless steel manufactured by PBF-LB during direct aging heat treatments at 621 °C (AMS H1150 standard condition), a route used to increase fracture toughness due to the martensite reversion and precipitates coarsening. The reversion of martensite into a Ni-rich austenite, predicted by kinetic calculations, was confirmed by high-energy X-ray diffraction (HE-XRD), being preferentially nucleated close to the copper-rich precipitates (CRPs), which can act as a preferential nucleation site. CRPs presented an oval shape, as confirmed by electronic microscopy (SEM and TEM) and atom probe tomography (APT). Fast Fourier transform (FFT) analysis of high-resolution TEM (HR-TEM) images suggests CRPs still present the metastable untwined 3R-type structure after 8 h, rather than the most stable FCC structure. The presence of retained austenite, inherent to PBF-LB-processed PH steels, affects the CRPs evolution in different phases, and the CRPs themselves act as nucleation sites for Nb(C,N) secondary precipitation. These findings emphasize the necessity of microstructure-oriented heat treatment routes to unlock the full potential of additively manufactured PH stainless steels.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121747"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.actamat.2025.121745
Ben Niu , Zhen Li , Jinlin Li , Qing Wang , Zhenhua Wang , Sen Ge , Tongmin Wang , Ruiqian Zhang , Peter K. Liaw , Junhua Luan , Zengbao Jiao
Excellent radiation resistance is essential for structural materials in nuclear reactors. In this work, a novel Ni-free body-centered-cubic (BCC) Fe-13.5Cr-4.7Al-2.1Mo-0.5Nb-0.8Ta-0.2Zr (wt. %) alloy with outstanding radiation tolerance was developed through irradiation-activated disordering-ordering transition of BCC-to-L21. A large amount of ultrafine L21-Fe3Al nanoparticles (< 4 nm) were found to precipitate coherently in the BCC matrix after triple-ion (Fe+ + He+ + H+) irradiation at 748 K. This nanoscale precipitation endows the alloy with an extremely-low irradiation swelling (∼ 0.3%), comparable to conventional oxide-dispersion-strengthened Fe-Cr-Al alloys. Remarkably, the L21 nanoprecipitates maintain a great stability at intermediate temperatures (673 ∼ 748 K), resulting in a minimal swelling (0.1 ∼ 0.2 %) under single Fe+ irradiation. This superior radiation resistance stems from high-density coherent interfaces between BCC-L21 phases with a larger lattice misfit, which can efficiently trap irradiation defects, accelerate vacancy-interstitial recombination, and suppress He bubble formation. In contrast, L21 nanoparticles were absent at either room temperature or 823 K, revealing a well-defined temperature window for irradiation-activated precipitation. Phase-field simulations and first-principles calculations further elucidated the disordering-ordering transition mechanism, demonstrating that the irradiation-enhanced diffusion of Al, along with the low formation and interfacial energies of coherent phases, critically govern the L21-Fe3Al nanoprecipitation. The present work presents a new alloy design strategy for developing next-generation radiation-tolerant structural materials.
{"title":"Enhanced radiation tolerance in Ni-free Fe-Cr-Al-based alloy via the disordering-ordering transition of coherent BCC-L21 phases","authors":"Ben Niu , Zhen Li , Jinlin Li , Qing Wang , Zhenhua Wang , Sen Ge , Tongmin Wang , Ruiqian Zhang , Peter K. Liaw , Junhua Luan , Zengbao Jiao","doi":"10.1016/j.actamat.2025.121745","DOIUrl":"10.1016/j.actamat.2025.121745","url":null,"abstract":"<div><div>Excellent radiation resistance is essential for structural materials in nuclear reactors. In this work, a novel Ni-free body-centered-cubic (BCC) Fe-13.5Cr-4.7Al-2.1Mo-0.5Nb-0.8Ta-0.2Zr (wt. %) alloy with outstanding radiation tolerance was developed through irradiation-activated disordering-ordering transition of BCC-to-L2<sub>1</sub>. A large amount of ultrafine L2<sub>1</sub>-Fe<sub>3</sub>Al nanoparticles (< 4 nm) were found to precipitate coherently in the BCC matrix after triple-ion (Fe<sup>+</sup> + He<sup>+</sup> + H<sup>+</sup>) irradiation at 748 K. This nanoscale precipitation endows the alloy with an extremely-low irradiation swelling (∼ 0.3%), comparable to conventional oxide-dispersion-strengthened Fe-Cr-Al alloys. Remarkably, the L2<sub>1</sub> nanoprecipitates maintain a great stability at intermediate temperatures (673 ∼ 748 K), resulting in a minimal swelling (0.1 ∼ 0.2 %) under single Fe<sup>+</sup> irradiation. This superior radiation resistance stems from high-density coherent interfaces between BCC-L2<sub>1</sub> phases with a larger lattice misfit, which can efficiently trap irradiation defects, accelerate vacancy-interstitial recombination, and suppress He bubble formation. In contrast, L2<sub>1</sub> nanoparticles were absent at either room temperature or 823 K, revealing a well-defined temperature window for irradiation-activated precipitation. Phase-field simulations and first-principles calculations further elucidated the disordering-ordering transition mechanism, demonstrating that the irradiation-enhanced diffusion of Al, along with the low formation and interfacial energies of coherent phases, critically govern the L2<sub>1</sub>-Fe<sub>3</sub>Al nanoprecipitation. The present work presents a new alloy design strategy for developing next-generation radiation-tolerant structural materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121745"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.actamat.2025.121731
Daehoon Jeong , Jae Sang Lee , Ho Jae Kwak , Sung-Joon Kim
The liquid-liquid phase separation (LLPS) behavior during solidification of Cu-Fe immiscible alloys with various Fe contents was observed in real time using in-situ X-ray imaging techniques. The coarsening and agglomeration behavior of Fe-rich droplets during LLPS was successfully visualized and compared with previously proposed coarsening mechanisms in immiscible alloys. This research revealed that the Fe-rich droplets move toward higher temperature regions to reduce their interfacial energy and that the linear relationship between speed and size causes collisions. In contrast, the buoyancy-driven movement and the diffusional coarsening were observed to play minor roles in coarsening and agglomeration during LLPS. Coalescence after droplet collision was found to be an additional source of droplet movement, causing an immediate displacement equivalent to the counterpart droplet's radius. Based on our observations, we modeled the agglomeration behavior with two simple equations and analyzed the time evolution of droplet size with various volume fractions of droplets and linear coefficients of droplet movement. Our investigation through real-time observation provides an immediate understanding of the microstructure evolution mechanism and an insight into critical factors affecting the degree of droplet agglomeration, which are useful for designing immiscible alloys.
{"title":"Real-time observation of liquid-liquid phase separation in Cu-Fe immiscible alloys using synchrotron X-rays","authors":"Daehoon Jeong , Jae Sang Lee , Ho Jae Kwak , Sung-Joon Kim","doi":"10.1016/j.actamat.2025.121731","DOIUrl":"10.1016/j.actamat.2025.121731","url":null,"abstract":"<div><div>The liquid-liquid phase separation (LLPS) behavior during solidification of Cu-Fe immiscible alloys with various Fe contents was observed in real time using in-situ X-ray imaging techniques. The coarsening and agglomeration behavior of Fe-rich droplets during LLPS was successfully visualized and compared with previously proposed coarsening mechanisms in immiscible alloys. This research revealed that the Fe-rich droplets move toward higher temperature regions to reduce their interfacial energy and that the linear relationship between speed and size causes collisions. In contrast, the buoyancy-driven movement and the diffusional coarsening were observed to play minor roles in coarsening and agglomeration during LLPS. Coalescence after droplet collision was found to be an additional source of droplet movement, causing an immediate displacement equivalent to the counterpart droplet's radius. Based on our observations, we modeled the agglomeration behavior with two simple equations and analyzed the time evolution of droplet size with various volume fractions of droplets and linear coefficients of droplet movement. Our investigation through real-time observation provides an immediate understanding of the microstructure evolution mechanism and an insight into critical factors affecting the degree of droplet agglomeration, which are useful for designing immiscible alloys.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"304 ","pages":"Article 121731"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing efficient and multifunctional materials is necessary to address global challenges like the energy crisis and environmental pollution. This study introduces a sustainable and scalable Co1-xNixO/ laser induced porous graphene (CoNiO/PG) nanohybrids, synthesized via a chemical co-precipitation method and a laser induced photothermal conversion process for dual applications in electrochemical supercapacitors and photocatalytic dye degradation. The CoNiO/PG nanohybrids demonstrated outstanding electrochemical supercapacitor performance, achieving a high specific areal capacitance of 3.53 mF cm-2 at 0.51 mA cm-2. A symmetric pouch cell fabricated using the nanohybrid delivered a specific areal capacitance of 2.17 mF cm-2 at 0.7 mA cm-2, with an energy density of 1.2 mWh cm-2 and a power density of 0.35 mW cm-2, retaining 89 % of its initial capacitance over 2000 cycles. Simultaneously, the nanohybrids displayed remarkable photocatalytic activity, achieving 94 % degradation of 5 ppm methylene blue dye within 120 min under UV–visible light. The enhanced photocatalytic activity arises from synergistic effects, including efficient electron-hole separation, reducing recombination losses, and the generation of reactive oxygen species, particularly hydroxyl radicals (•OH), as supported by photoluminescence and radical scavenger studies. The laser induced porous graphene structure enhanced charge transfer and catalytic efficiency, while the CoNiO nanoflakes provided active sites and facilitated pseudocapacitance. Furthermore, the CoNiO/PG photocatalyst exhibited excellent recyclability, retaining its photocatalytic efficiency over five consecutive cycles with negligible performance loss. This work underscores the potential of metal oxide/graphene-nanohybrids as scalable and cost-effective solution for advanced energy storage and environmental remediation, paving the way for sustainable technologies.
开发高效、多功能的材料是应对能源危机和环境污染等全球性挑战的必要条件。本研究介绍了一种可持续和可扩展的Co1-xNixO/激光诱导多孔石墨烯（CoNiO/PG）纳米杂化材料，该材料通过化学共沉淀法和激光诱导光热转换工艺合成，可用于电化学超级电容器和光催化染料降解。CoNiO/PG纳米杂化材料表现出优异的电化学超级电容器性能，在0.51 mA cm-2下实现了3.53 mF cm-2的高比面积电容。使用纳米杂化材料制备的对称袋状电池在0.7 mA cm-2时的比面积电容为2.17 mF cm-2，能量密度为1.2 mWh cm-2，功率密度为0.35 mW cm-2，在2000次循环中保持89%的初始电容。同时，纳米杂化物表现出优异的光催化活性，在紫外-可见光下，120分钟内对5 ppm亚甲基蓝染料的降解率达到94%。增强的光催化活性源于协同效应，包括有效的电子空穴分离，减少重组损失，以及活性氧的产生，特别是羟基自由基（•OH），这些都得到了光致发光和自由基清除剂研究的支持。激光诱导的多孔石墨烯结构增强了电荷转移和催化效率，而CoNiO纳米片提供了活性位点并促进了赝电容。此外，CoNiO/PG光催化剂表现出优异的可回收性，在连续五个循环中保持其光催化效率，性能损失可以忽略不计。这项工作强调了金属氧化物/石墨烯纳米混合材料作为可扩展且具有成本效益的先进储能和环境修复解决方案的潜力，为可持续技术铺平了道路。
{"title":"Hierarchically structured Co1-X NiXO/laser induced porous graphene nanohybrids for supercapacitors and dye degradation","authors":"Mutcha Shanmukha Rao , Shradha Suman , Benadict Rakesh , Ramasamy Sakthivel , Kamatchi Jothiramalingam Sankaran","doi":"10.1016/j.actamat.2025.121748","DOIUrl":"10.1016/j.actamat.2025.121748","url":null,"abstract":"<div><div>Developing efficient and multifunctional materials is necessary to address global challenges like the energy crisis and environmental pollution. This study introduces a sustainable and scalable Co<sub>1-x</sub>Ni<sub>x</sub>O/ laser induced porous graphene (CoNiO/PG) nanohybrids, synthesized via a chemical co-precipitation method and a laser induced photothermal conversion process for dual applications in electrochemical supercapacitors and photocatalytic dye degradation. The CoNiO/PG nanohybrids demonstrated outstanding electrochemical supercapacitor performance, achieving a high specific areal capacitance of 3.53 mF cm<sup>-2</sup> at 0.51 mA cm<sup>-2</sup>. A symmetric pouch cell fabricated using the nanohybrid delivered a specific areal capacitance of 2.17 mF cm<sup>-2</sup> at 0.7 mA cm<sup>-2</sup>, with an energy density of 1.2 mWh cm<sup>-2</sup> and a power density of 0.35 mW cm<sup>-2</sup>, retaining 89 % of its initial capacitance over 2000 cycles. Simultaneously, the nanohybrids displayed remarkable photocatalytic activity, achieving 94 % degradation of 5 ppm methylene blue dye within 120 min under UV–visible light. The enhanced photocatalytic activity arises from synergistic effects, including efficient electron-hole separation, reducing recombination losses, and the generation of reactive oxygen species, particularly hydroxyl radicals (•OH), as supported by photoluminescence and radical scavenger studies. The laser induced porous graphene structure enhanced charge transfer and catalytic efficiency, while the CoNiO nanoflakes provided active sites and facilitated pseudocapacitance. Furthermore, the CoNiO/PG photocatalyst exhibited excellent recyclability, retaining its photocatalytic efficiency over five consecutive cycles with negligible performance loss. This work underscores the potential of metal oxide/graphene-nanohybrids as scalable and cost-effective solution for advanced energy storage and environmental remediation, paving the way for sustainable technologies.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"304 ","pages":"Article 121748"},"PeriodicalIF":9.3,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-18DOI: 10.1016/j.actamat.2025.121717
E. Kasotakis , T. Smoliarova , I. Tarasov , M. Grzywa , M. Farle , N.F. Shkodich
Nanocrystalline CoCrFeMnNi-Agx (x = 0; 1; 2.5; 5.5 at. %) high-entropy alloy (HEA) powders were synthesized for the first time via rapid, two-step high-energy ball milling (HEBM) in Ar. A single-phase fcc Cantor alloy with uniform elemental distribution was obtained after just 60 min of HEBM from an elemental powder blend. Subsequent HEBM for 10 min with Ag addition enabled precise control over Ag distribution and particle morphology, which evolved from flake-like structures with Ag-rich edges (x = 1; 2.5 at. %) to homogeneous spherical particles (x = 5.5 at. %). All compositions exhibit paramagnetic behavior at 310 K, with Curie temperatures (Tc) decreasing from 96 K (Ag-free CoCrFeMnNi) to 71 K (Ag = 5.5 at. %), indicating suppression of magnetic ordering. Importantly, annealing up to 710 K in a magnetic field significantly enhances the magnetic response across all compositions. The CoCrFeMnNi-Agx (x = 2.5 at. %) HEA shows the most pronounced improvement, with magnetization (M) (9 T, 310 K) increasing 2.5-fold to 16 Am²/kg, coercivity (Hc) reaching 46 kA/m, and remanence of 4.8 Am2/kg. Notably, M approaches ∼ 1/3 of pure Ni under the same conditions, while exhibiting a Hc nearly two orders of magnitude higher.
These results highlight that Ag alloying and thermal treatment offer an effective approach to tuning magnetic properties in CoCrFeMnNi-based HEAs without compromising structural integrity. The ability to tailor structure, morphology, and magnetism through a scalable route promotes Ag-doped Cantor alloys as promising candidates for multifunctional applications requiring combined structural and magnetic performance.
{"title":"Tailoring structure, morphology, composition, and magnetism by Ag addition to CoCrFeMnNi-Agx (x = 0; 1; 2.5; 5.5 at. %) high-entropy alloy powders prepared by high-energy ball milling","authors":"E. Kasotakis , T. Smoliarova , I. Tarasov , M. Grzywa , M. Farle , N.F. Shkodich","doi":"10.1016/j.actamat.2025.121717","DOIUrl":"10.1016/j.actamat.2025.121717","url":null,"abstract":"<div><div>Nanocrystalline CoCrFeMnNi-Ag<sub>x</sub> (<em>x</em> = 0; 1; 2.5; 5.5 at. %) high-entropy alloy (HEA) powders were synthesized for the first time via rapid, two-step high-energy ball milling (HEBM) in Ar. A single-phase <em>fcc</em> Cantor alloy with uniform elemental distribution was obtained after just 60 min of HEBM from an elemental powder blend. Subsequent HEBM for 10 min with Ag addition enabled precise control over Ag distribution and particle morphology, which evolved from flake-like structures with Ag-rich edges (<em>x</em> = 1; 2.5 at. %) to homogeneous spherical particles (<em>x</em> = 5.5 at. %). All compositions exhibit paramagnetic behavior at 310 K, with Curie temperatures (<em>T</em><sub>c</sub>) decreasing from 96 K (Ag-free CoCrFeMnNi) to 71 K (Ag = 5.5 at. %), indicating suppression of magnetic ordering. Importantly, annealing up to 710 K in a magnetic field significantly enhances the magnetic response across all compositions. The CoCrFeMnNi-Ag<sub>x</sub> (<em>x</em> = 2.5 at. %) HEA shows the most pronounced improvement, with magnetization (<em>M</em>) (9 T, 310 K) increasing 2.5-fold to 16 Am²/kg, coercivity (<em>H</em><sub>c</sub>) reaching 46 kA/m, and remanence of 4.8 Am<sup>2</sup>/kg. Notably, <em>M</em> approaches ∼ 1/3 of pure Ni under the same conditions, while exhibiting a <em>H</em><sub>c</sub> nearly two orders of magnitude higher.</div><div>These results highlight that Ag alloying and thermal treatment offer an effective approach to tuning magnetic properties in CoCrFeMnNi-based HEAs without compromising structural integrity. The ability to tailor structure, morphology, and magnetism through a scalable route promotes Ag-doped Cantor alloys as promising candidates for multifunctional applications requiring combined structural and magnetic performance.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121717"},"PeriodicalIF":9.3,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-18DOI: 10.1016/j.actamat.2025.121743
Xianqiang Yu , Yuezhu Wang , Mingze Xia , Li Deng , Ruikai Qi , Mingbin Gao , Mengxiao Zhong , Xiaofeng Lu
Manipulating the electronic structure of heterogeneous catalysts to optimize the adsorption behavior of hydrogen intermediate (H*) is essential for enhancing the hydrogen evolution reaction (HER), representing a key objective in advancing efficient hydrogen (H2) production. Herein, we have engineered the electronic configuration by coupling ruthenium (Ru) nanoparticles with molybdenum carbide (Mo2C)/N-doped carbon fibers (NCF) to greatly enhance the electrocatalytic alkaline/acidic-universal HER performance. The obtained Ru@Mo2C/NCF catalyst exhibits ultralow overpotentials of 182 and 193 mV at an industrial-grade current density (1 A cm⁻2) in 1 M KOH and 0.5 M H2SO4, respectively, significantly surpassing commercial Pt/C and many traditional HER catalysts. The catalyst also demonstrates an exceptional long-term stability in both alkaline and acidic conditions, even greatly better than Pt/C catalyst. Theoretical analysis reveals that the coupling of Ru with Mo2C/NCF optimize the H* adsorption and facilitates H2 releasing. Furthermore, a zinc-water (Zn-H2O) battery is assembled to realize highly efficient and simultaneous H2 and electricity generation, demonstrating its practicability.
控制非均相催化剂的电子结构以优化氢中间体（H*）的吸附行为是提高析氢反应（HER）的必要条件，是推进高效制氢（H2）的关键目标。在此，我们通过将钌（Ru）纳米颗粒与碳化钼(Mo2C)/ n掺杂碳纤维（NCF）偶联来设计电子构型，以大大提高电催化碱性/酸性通用HER性能。所得Ru@Mo2C/NCF催化剂在1 M KOH和0.5 M H2SO4中，在工业级电流密度（1 A cm⁻2）下分别表现出182和193 mV的超低过电位，显著优于商业Pt/C和许多传统的HER催化剂。该催化剂在碱性和酸性条件下都表现出优异的长期稳定性，甚至远远优于Pt/C催化剂。理论分析表明，Ru与Mo2C/NCF的耦合优化了H*吸附，促进了H2的释放。此外，还组装了锌水（Zn-H2O）电池，实现了高效、同时产氢和发电，展示了其实用性。
{"title":"Modulating hydrogen intermediate on Ru@Mo2C/N-doped carbon fibers boosts ampere-level alkaline/acidic hydrogen evolution performance","authors":"Xianqiang Yu , Yuezhu Wang , Mingze Xia , Li Deng , Ruikai Qi , Mingbin Gao , Mengxiao Zhong , Xiaofeng Lu","doi":"10.1016/j.actamat.2025.121743","DOIUrl":"10.1016/j.actamat.2025.121743","url":null,"abstract":"<div><div>Manipulating the electronic structure of heterogeneous catalysts to optimize the adsorption behavior of hydrogen intermediate (H*) is essential for enhancing the hydrogen evolution reaction (HER), representing a key objective in advancing efficient hydrogen (H<sub>2</sub>) production. Herein, we have engineered the electronic configuration by coupling ruthenium (Ru) nanoparticles with molybdenum carbide (Mo<sub>2</sub>C)/N-doped carbon fibers (NCF) to greatly enhance the electrocatalytic alkaline/acidic-universal HER performance. The obtained Ru@Mo<sub>2</sub>C/NCF catalyst exhibits ultralow overpotentials of 182 and 193 mV at an industrial-grade current density (1 A cm⁻<sup>2</sup>) in 1 M KOH and 0.5 M H<sub>2</sub>SO<sub>4</sub>, respectively, significantly surpassing commercial Pt/C and many traditional HER catalysts. The catalyst also demonstrates an exceptional long-term stability in both alkaline and acidic conditions, even greatly better than Pt/C catalyst. Theoretical analysis reveals that the coupling of Ru with Mo<sub>2</sub>C/NCF optimize the H* adsorption and facilitates H<sub>2</sub> releasing. Furthermore, a zinc-water (Zn-H<sub>2</sub>O) battery is assembled to realize highly efficient and simultaneous H<sub>2</sub> and electricity generation, demonstrating its practicability.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121743"},"PeriodicalIF":9.3,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-18DOI: 10.1016/j.actamat.2025.121728
Hengyang Wang , Siyun Liu , Guang Han , Bin Zhang , Xiaolan Mo , Yao Chen , Kaiqi Zhang , Xu Lu , Guoyu Wang , Xiaoyuan Zhou
Ag2Se, with potential for efficient thermoelectric conversion near room temperature, holds promise for extensive applications in solid-state cooling and low-grade waste heat recovery. Rational design and synthesis of an appropriate second phase to boost the thermoelectric and mechanical properties of Ag2Se are beneficial for practical use yet challenging. Herein, we realize the in situ formation of three types of Te-alloyed, high-hardness AgXSe2 (X = Bi, In, Sb; i.e., AgX(Se,Te)2) second phases by triggering the reaction between Ag2Se and X2Te3 nanomaterials via sintering, which also hinders the grain growth of Ag2Se effectively. The multi-scale microstructures enhance phonon scattering and in turn lead to enhanced dimensionless figure of merit (zT), as exemplified by an excellent average zT of 0.98 in the composite with appropriate amount of AgSb(Se,Te)2. Mechanically, enabled by the AgX(Se,Te)2 inclusions with uniform distribution and high amount, as well as higher-density grain boundaries, the optimal composite obtains a compressive strength of 218.8 MPa, which compares favorably to previous reports. This work demonstrates the efficacy of the in situ second phase formation strategy for simultaneously improving the thermoelectric and mechanical properties of n-type Ag2Se-based materials.
Ag2Se具有在室温附近进行高效热电转换的潜力，有望在固态冷却和低品位废热回收方面得到广泛应用。合理设计和合成合适的第二相以提高Ag2Se的热电性能和力学性能，对实际应用是有益的，但也具有挑战性。本文通过烧结触发Ag2Se与X2Te3纳米材料之间的反应，实现了三种类型的Te合金高硬度AgXSe2 （X = Bi, in, Sb，即AgX(Se,Te)2）第二相的原位形成，也有效地阻碍了Ag2Se的晶粒生长。多尺度的微观结构增强了声子散射，从而提高了无因次优值（zT），例如，添加适量AgSb(Se,Te)2的复合材料的平均zT为0.98。机械性能方面，由于AgX(Se,Te)2夹杂物分布均匀且含量高，晶界密度高，复合材料抗压强度达到218.8 MPa，优于以往的研究结果。这项工作证明了原位第二相形成策略在同时改善n型ag2se基材料的热电性能和力学性能方面的有效性。
{"title":"Rational design and synthesis of second phases in n-type Ag2Se-based composites for enhanced thermoelectric and mechanical properties","authors":"Hengyang Wang , Siyun Liu , Guang Han , Bin Zhang , Xiaolan Mo , Yao Chen , Kaiqi Zhang , Xu Lu , Guoyu Wang , Xiaoyuan Zhou","doi":"10.1016/j.actamat.2025.121728","DOIUrl":"10.1016/j.actamat.2025.121728","url":null,"abstract":"<div><div>Ag<sub>2</sub>Se, with potential for efficient thermoelectric conversion near room temperature, holds promise for extensive applications in solid-state cooling and low-grade waste heat recovery. Rational design and synthesis of an appropriate second phase to boost the thermoelectric and mechanical properties of Ag<sub>2</sub>Se are beneficial for practical use yet challenging. Herein, we realize the <em>in situ</em> formation of three types of Te-alloyed, high-hardness AgXSe<sub>2</sub> (<em>X</em> = Bi, In, Sb; <em>i.e.</em>, AgX(Se,Te)<sub>2</sub>) second phases by triggering the reaction between Ag<sub>2</sub>Se and X<sub>2</sub>Te<sub>3</sub> nanomaterials <em>via</em> sintering, which also hinders the grain growth of Ag<sub>2</sub>Se effectively. The multi-scale microstructures enhance phonon scattering and in turn lead to enhanced dimensionless figure of merit (<em>zT</em>), as exemplified by an excellent average <em>zT</em> of 0.98 in the composite with appropriate amount of AgSb(Se,Te)<sub>2</sub>. Mechanically, enabled by the AgX(Se,Te)<sub>2</sub> inclusions with uniform distribution and high amount, as well as higher-density grain boundaries, the optimal composite obtains a compressive strength of 218.8 MPa, which compares favorably to previous reports. This work demonstrates the efficacy of the <em>in situ</em> second phase formation strategy for simultaneously improving the thermoelectric and mechanical properties of n-type Ag<sub>2</sub>Se-based materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"303 ","pages":"Article 121728"},"PeriodicalIF":9.3,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145535392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-17DOI: 10.1016/j.actamat.2025.121737
Q.F. He, S.H. Ma, D.H. Chung, H. Wang, Z.Q. Chen, Z.Y. Ding, Q. Yu, J.H. Luan, Q. Wang, F. Zhang, H.B. Lou, Q.S. Zeng, J.F. Gu, S.J. Zhao, Y. Yang
Topologically close-packed (TCP) phases like Laves phase are prevalent in high-performance engineering alloys but are traditionally associated with notorious brittleness at room temperature, often degrading toughness even at trace concentrations. Here, we report the design of a metastable, multi-principal-element TCP phase (designated M phase) in a complex eutectic alloy that exhibits both high strength and unusual deformability which are incomparable with conventional TCP phases. The remarkable properties originate from that the M phase can undergo a reversible, shear-activated polytypic transformation to C14 Laves phase under stress - a deformation mechanism not previously observed in conventional TCP phases. This shear-activated transformation dramatically enhances energy dissipation, enabling intrinsic crack-tip plasticity despite containing ∼50 vol% TCP phases, ultimately achieving a record room-temperature fracture toughness of 62 MPa∙m0.5 for TCP-containing alloys. Furthermore, the transformation’s reversibility imparts extraordinary thermomechanical processability: the alloy withstands compressive strains exceeding 75% without failure through controlled cyclic loading—plasticity levels previously thought unattainable for TCP-rich materials. These findings reveal a transformative physical mechanism for toughening intrinsically brittle intermetallics and open a new paradigm for designing strong, ductile, and processable structural materials via metastable TCP phase engineering.
{"title":"Polytypical Phase Transformation of Topologically Close-Packed Phase Enabled Toughening in Multi-Principal-Element Eutectic Alloy","authors":"Q.F. He, S.H. Ma, D.H. Chung, H. Wang, Z.Q. Chen, Z.Y. Ding, Q. Yu, J.H. Luan, Q. Wang, F. Zhang, H.B. Lou, Q.S. Zeng, J.F. Gu, S.J. Zhao, Y. Yang","doi":"10.1016/j.actamat.2025.121737","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121737","url":null,"abstract":"Topologically close-packed (TCP) phases like Laves phase are prevalent in high-performance engineering alloys but are traditionally associated with notorious brittleness at room temperature, often degrading toughness even at trace concentrations. Here, we report the design of a metastable, multi-principal-element TCP phase (designated M phase) in a complex eutectic alloy that exhibits both high strength and unusual deformability which are incomparable with conventional TCP phases. The remarkable properties originate from that the M phase can undergo a reversible, shear-activated polytypic transformation to C14 Laves phase under stress - a deformation mechanism not previously observed in conventional TCP phases. This shear-activated transformation dramatically enhances energy dissipation, enabling intrinsic crack-tip plasticity despite containing ∼50 vol% TCP phases, ultimately achieving a record room-temperature fracture toughness of 62 MPa∙m<sup>0.5</sup> for TCP-containing alloys. Furthermore, the transformation’s reversibility imparts extraordinary thermomechanical processability: the alloy withstands compressive strains exceeding 75% without failure through controlled cyclic loading—plasticity levels previously thought unattainable for TCP-rich materials. These findings reveal a transformative physical mechanism for toughening intrinsically brittle intermetallics and open a new paradigm for designing strong, ductile, and processable structural materials via metastable TCP phase engineering.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"64 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145531761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号