The strength and plasticity of Fe_(39)Ni_(39)B_(12.82)Si_(2.75)Nb_(2.3)P_(4.13)bulk metallic glass(BMG)are improved simultaneously by modulating atomic-scale structure through fluxing treatment.The compression strengt...The strength and plasticity of Fe_(39)Ni_(39)B_(12.82)Si_(2.75)Nb_(2.3)P_(4.13)bulk metallic glass(BMG)are improved simultaneously by modulating atomic-scale structure through fluxing treatment.The compression strength increases from 3074 to 4220 MPa,and the plastic strain is enlarged from 10.7%to more than 50%.The increased mechanical properties of the fluxed Fe Ni BSi Nb P BMG originate from the optimization of atomic-scale structure.More icosahedral-like clusters(ILCs)and crystal-like clusters(CLCs)are found in this Fe Ni-based BMG with fluxing treatment,and the ILCs are usually surrounded by CLCs.Furthermore,phase separation and a sandwich-like heterogeneous structure of SB are also observed during deformation,indicating the multiscale deformation mechanism and a stable shear-band evolution.The unique"ILC surrounded by CLCs"structure and phase separation lead to a stable plastic deformation process with strong interactions of multiple shear bands,thereby the improved plasticity and strength.This work provides useful guidelines to develop strong and plastic Fe-based BMGs from a structural aspect.展开更多
Ms-T curves and hysteresis loops were investigated for amorphous Fe78Si9B13, (FeNi)78(CrSiB)22, their lap-wound-cores, and their composite ribbons made by two-chamber-crucible technique. The properties of the lap-woun...Ms-T curves and hysteresis loops were investigated for amorphous Fe78Si9B13, (FeNi)78(CrSiB)22, their lap-wound-cores, and their composite ribbons made by two-chamber-crucible technique. The properties of the lap-wound cores of the two kinds of ribbons are similar. For the composite ribbons, the intrinsic properties are the average of the two alloys. Their technological properties, i.e., hysteresis loops, however, are no longer the average of the two alloys. Instead, they show some dramatic changes compared to the lap-wound-cores. Especially, the shape of the hysteresis loop of the composite ribbon cores is largely different from that of lap-wound-cores. The reason for the difference is supposed to be internal stress induced from cooling after annealing.展开更多
FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of...FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of their counterparts.Thus,uncovering the solidification and anomalous nano-crystallization behavior of FeNi-based MGs is crucial to the development of FeNibased bulk metallic glasses with larger plasticity and critical size concurrently.Regarding this,a combination of complementary in situ synchrotron radiation high-energy X-ray diffraction,small-angle neutron scattering(SANS),and 3-dimentional atom probe tomography(3-D APT)is used to study solidification and nano-crystallization behavior of Fe_(48)Ni_(30)Mo_(3)B_(19)liquid and MG.The time–temperature–transformation diagram was successfully depicted via melting spun,in situ solidification,and isothermal annealing methods.We found that the Fe_(48)Ni_(30)Mo_(3)B_(19)MG can only be prepared via the meltspinning method to obtain amorphous ribbons,which could contribute to the low activation energy for the nano-crystallization growth E_(p).Moreover,during isothermal annealing,the anomalous slow growth behavior in kinetic of theγ-FeNi phase embedded in the amorphous matrix is caused by the Fe and Ni partitioning,and the Mo-enriched region around the nanosizedγ-FeNi phase,which is revealed by 3-D APT.These results exhibit a new perspective for understanding the relationship between GFA and nano-crystallization behavior and provide feasible guidance for the development of newγ-FeNi-containing Fe-based BMG composites with desired mechanical properties and GFA.展开更多
Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced ...Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.展开更多
基金the National Natural Science Foundation of China(Grant Nos.51631003 and 51871054)the Fundamental Research Funds for the Central Universities(Grant Nos.2242019k1G005 and 2242019K40183)the Department of Energy(DOE)Office of Science(DE-AC02-06CH11357)。
文摘The strength and plasticity of Fe_(39)Ni_(39)B_(12.82)Si_(2.75)Nb_(2.3)P_(4.13)bulk metallic glass(BMG)are improved simultaneously by modulating atomic-scale structure through fluxing treatment.The compression strength increases from 3074 to 4220 MPa,and the plastic strain is enlarged from 10.7%to more than 50%.The increased mechanical properties of the fluxed Fe Ni BSi Nb P BMG originate from the optimization of atomic-scale structure.More icosahedral-like clusters(ILCs)and crystal-like clusters(CLCs)are found in this Fe Ni-based BMG with fluxing treatment,and the ILCs are usually surrounded by CLCs.Furthermore,phase separation and a sandwich-like heterogeneous structure of SB are also observed during deformation,indicating the multiscale deformation mechanism and a stable shear-band evolution.The unique"ILC surrounded by CLCs"structure and phase separation lead to a stable plastic deformation process with strong interactions of multiple shear bands,thereby the improved plasticity and strength.This work provides useful guidelines to develop strong and plastic Fe-based BMGs from a structural aspect.
文摘Ms-T curves and hysteresis loops were investigated for amorphous Fe78Si9B13, (FeNi)78(CrSiB)22, their lap-wound-cores, and their composite ribbons made by two-chamber-crucible technique. The properties of the lap-wound cores of the two kinds of ribbons are similar. For the composite ribbons, the intrinsic properties are the average of the two alloys. Their technological properties, i.e., hysteresis loops, however, are no longer the average of the two alloys. Instead, they show some dramatic changes compared to the lap-wound-cores. Especially, the shape of the hysteresis loop of the composite ribbon cores is largely different from that of lap-wound-cores. The reason for the difference is supposed to be internal stress induced from cooling after annealing.
基金financially supported by the National Key R&D Program of China(No.2022YFA1603801)the Open Fund of the Science and Technology on Metrology and Calibration Laboratory(No.JLKG2023001C004)+6 种基金the National Natural Science Foundation of China(Nos.52130108,52301213,52071024,52271003,and 52101188)Guangdong Basic and Applied Basic Research Foundation(Nos.2022A1515110805,2021B1515140028,and 2021CX02C087)the Open Fund of the China Spallation Neutron Source Songshan Lake Science City(No.KFKT2023B11)Construction of a Coordination Network for Science and Technology Assistance to Latin American Countries(Science and Technology Partnership Program,Ministry of Science and Technology of China,No.KY202401006)the Youth Innovation Promotion Association,CAS(No.2020010)the State Key Lab of Advanced Metals and Materials(No.2022-ZD01)the SSRF proposal(No.2024-SSRF-PT-506766)
文摘FeNi-based MGs exhibit the most excellent room-temperature mechanical properties among different Fe-based metallic glasses(MGs)systems.However,the glass-forming ability(GFA)of FeNi-based MGs is much lower than that of their counterparts.Thus,uncovering the solidification and anomalous nano-crystallization behavior of FeNi-based MGs is crucial to the development of FeNibased bulk metallic glasses with larger plasticity and critical size concurrently.Regarding this,a combination of complementary in situ synchrotron radiation high-energy X-ray diffraction,small-angle neutron scattering(SANS),and 3-dimentional atom probe tomography(3-D APT)is used to study solidification and nano-crystallization behavior of Fe_(48)Ni_(30)Mo_(3)B_(19)liquid and MG.The time–temperature–transformation diagram was successfully depicted via melting spun,in situ solidification,and isothermal annealing methods.We found that the Fe_(48)Ni_(30)Mo_(3)B_(19)MG can only be prepared via the meltspinning method to obtain amorphous ribbons,which could contribute to the low activation energy for the nano-crystallization growth E_(p).Moreover,during isothermal annealing,the anomalous slow growth behavior in kinetic of theγ-FeNi phase embedded in the amorphous matrix is caused by the Fe and Ni partitioning,and the Mo-enriched region around the nanosizedγ-FeNi phase,which is revealed by 3-D APT.These results exhibit a new perspective for understanding the relationship between GFA and nano-crystallization behavior and provide feasible guidance for the development of newγ-FeNi-containing Fe-based BMG composites with desired mechanical properties and GFA.
基金supported by the National Natural Science Foundation of China(21972124 and 22272148)。
文摘Advancing and deploying the Fe Ni-based catalyst,the state-of-the-art pre-electrocatalysts,for oxygen evolution reactions(OER)still suffer from unclear chemical state correlation to the catalytic ability,as evidenced by the variedly reported performance for the different Fe Ni structures.Herein,we contributed the phase and redox chemical states tuning of Fe Ni oxides by the surface microenvironment regulation for the OER catalysis that was realized by the urea-assisted pyrolysis and molybdenum-doping technique by integrating molybdenum into the iron–nickel metal-organic precursor.Driven by the complicated and compromised atmosphere,namely,the oxidation state driven by the Mo doping and reduction ability induced by the urea-assisted pyrolysis,could transfer confined Fe Ni oxides to hybrid phases of Fe_(2)O_(3)and FeNi_(3)alloy,and the resultant compromised chemical states by the charge redistribution imparted very high electrocatalytic performance for OER compared with the control samples.The insitu Raman spectroscopy and post-XPS analysis confirmed the facile Fe/Ni oxyhydroxide active phase formation resulting from the proper phase and chemical states,and theoretical analysis disclosed the microenvironment regulation resulting in the charge redistribution forming the electron accumulation and depletion sites to accelerate the oxygen-species to oxyhydroxide-species transformation and enhance the electronic state density near the Fermi level by significantly reducing the energy barrier.The work not only showed the importance of surface chemical state tunning that can basically answer the varied performance of Fe Ni catalysts but also revealed an effective approach for fine-tuning their catalytic properties.
