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Developing Core-Shell Nano-Structures in FeCrAl-ODS Ferritic Alloys with the Co-Addition of Ni and Zr

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 364-372页

作者： Wenquan Ding Jieli Ma Yong Jiang Yiren Wang Huiqun Liu key laboratory for nonferrous materials of Ministry of Education School of Materials Science and EngineeringCentral South UniversityChangsha410083China National key laboratory for Powder Metallurgy Central South UniversityChangsha410083China

A new Ni+Zr co-alloyed FeCrAl-ODS(oxide-dispersion-strengthened)ferritic alloy was fabricated by ball-milling and *** electron microscopy and atom probe tomography,the dispersive formation of high density core-shelled nano-particles of various sizes was confirmed with a common B2-NiAl *** which,median-sized nano-particles(20-50 nm)typically have an Y_(4)Al_(2)O_(9)nano-core of<~20 nm,ultra-fine nano-particles(<~20)nm have an Y_(4)Zr_(3)O_(12)nano-core of<~10 nm,and larger-sized nano-particles(50-100 nm)incorporate an ultra-fine Y_(4)Al_(2)O_(9)nano-core and a few ultra-fine Y_(4)Zr_(3)O_(12)*** these nano-phases were highly coherent with the ferritic *** large Y--Al-O nano-oxides were *** total number density of ultra-fine nano-particles was estimated as~2×10^(23)m^(-3)with a mean size of 6.3 nm only,and accordingly,the new alloy achieved an excellent combination of strength and ductility at high temperatures.

关键词： FeCrAl Oxide-dispersion-strengthened(ODS)alloy Mechanical alloying Nano-oxides Core-shell

Effect of forging on the microstructure and texture of a high Nb containing γ-TiAl alloy

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Journal of Central South University 2024年第6期31卷 1763-1773页

作者： TAO Hui LI Hui-zhong WANG Li ZHOU Rui CHE Yi-xuan CHEN Yong-hui LIANG Xiao-peng School of materials science and engineering Central South UniversityChangsha 410083China State key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China key laboratory of nonferrous Metal materials science and engineering Central South UniversityChangsha 410083China Department of materials science and engineering City University of Hong KongKowloon 999077Hong KongChina

The effect of forging on the microstructure and texture evolution of a high Nb containing Ti-45Al-7Nb-0.3W(at.%)alloy was investigated by X-ray diffractometer(XRD),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).The results show that the as-cast alloy is mainly composed of α_(2)/γ lamellar colonies with a mean size of 70μm,but the hot-forged pancake displays a near duplex microstructure(DP).Kinking and bending of lamellar colonies,deformation twinning and dynamic recrystallization(DRX)occur during hot ***,dense dislocations in theβphase after forging suggest that the high-temperature β phase with a disordered structure is favorable for improving the hot-workability of the *** the common TiAl casting texture,the solidification process of the investigated as-cast alloy with high Nb content is completely via the β phase region,resulting in the formation of aγ fiber texture where theγ aligns parallel to the heat-flow *** comparison,the relatively strongand weaktexture components in the as-forged alloy are attributed to the deformation *** annealing,static recrystallization occurs at the twin boundary and intersections,which weakens the deformation texture.

关键词： high Nb containing γ-TiAl alloy forging microstructure texture β phase

Coupling Co-Ni phosphides for energy-saving alkaline seawater splitting

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Nano Research 2024年第6期17卷 4797-4806页

作者： Weijia Liu Wenxian Liu Tong Hou Junyang Ding Zhigui Wang Ruilian Yin Xingyuan San Ligang Feng Jun Luo Xijun Liu State key laboratory of Featured Metal materials and Life-cycle Safety for Composite Structures Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured MaterialsMOE Key Laboratory of New Processing Technology for Nonferrous Metals and MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China College of materials science and engineering Zhejiang University of TechnologyHangzhou 310014China Hebei key laboratory of Optic-electronic Information and materials the College of Physics Science and TechnologyHebei UniversityBaoding 071002China School of Chemistry and Chemical engineering Yangzhou UniversityYangzhou 225002China ShenSi lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaShenzhen 518110China

The coupling of energy-saving small molecule conversion reactions and hydrogen evolution reaction(HER)in seawater electrolytes can reduce the energy consumption of seawater electrolysis and mitigate chlorine corrosion ***,the fabrication of efficient multifunctional catalysts for this promising technology is of great ***,a heterostructured catalyst comprising CoP and Ni_(2)P on nickel foam(CoP/Ni_(2)P@NF)is reported for hydrazine oxidation(HzOR)-assisted alkaline seawater *** coupling of CoP and Ni_(2)P optimizes the electronic structure of the active sites and endows excellent electrocatalytic performance for HzOR and ***,the two-electrode HzOR-assisted alkaline seawater splitting(OHzS)cell based on the CoP/Ni_(2)P@NF required only 0.108 V to deliver 100 mA·cm^(−2),much lower than 1.695 V for alkaline seawater electrolysis ***,the OHzS cell exhibits satisfactory stability over 48 h at a high current density of 500 mA·cm^(−2).Furthermore,the CoP/Ni_(2)P@NF heterostructured catalyst also efficiently catalyzed glucose oxidation,methanol oxidation,and urea oxidation in alkaline seawater *** work paves a path for high-performance heterostructured catalyst preparation for energy-saving seawater electrolysis for H_(2) production.

关键词： seawater splitting heterostructure electrocatalysis hydrazine oxidation reaction hydrogen evolution reaction

Progress in preparation of AlN-reinforced magnesium matrix composites:A review

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China Foundry 2024年第1期21卷 1-10页

作者： Lu Chen Shu-lin Lü Di-jia Zhao Wei Guo Jian-yu Li Shu-sen Wu State key lab of materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

As a ceramic material,AlN has very good thermophysical and mechanical *** addition,AlN is an effective refining agent for Mg alloys because it has a lattice constant similar to that of ***,AlN is an ideal reinforcement for magnesium matrix composites(MMCs),and is attracting increasing *** review addresses the development of preparation technologies for AlN-reinforced Mg matrix *** mainstream preparation techniques include stir casting,melt infiltration,powder metallurgy,and in-situ *** addition,the advantages and disadvantages of these techniques are analyzed in depth,and it is pointed out that the next direction for the preparation of high-performance AlN-reinforced MMCs is less aluminization and multiple technologies integration.

关键词： AlN MMCs preparation thermophysical property mechanical property

UltrahighQ Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)microwave dielectric ceramics for temperature-stable millimeter-wave dielectric resonator antennas

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Journal of Advanced Ceramics 2024年第2期13卷 155-165页

作者： Guoqiang He Yu Jiang Kaixin Song Yanjun Liu Yuan Nie Wenjie Zhang Ziqi Zhao Yinghan He Xinyue Ma Xiuli Chen Xu Li Huanfu Zhou Collaborative Innovation Centre for Exploration of Hidden nonferrous Metal Deposits and Development of New materials in Guangxi Key Laboratory of Nonferrous Materials and New Processing TechnologyMinistry of EducationSchool of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004China College of Electronic Information Hangzhou Dianzi UniversityHangzhou 310018China

Microwave dielectric ceramics should be improved to advance mobile communication technologies *** this study,we prepared Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics with nonstoichiometric Sr^(2+)ratios based on our previously reported SrY_(2)O_(4) microwave dielectric ceramic,which has a low dielectric constant and an ultrahigh quality factor(Q value).The ceramic exhibited a 33.6% higher Q-by-frequency(Q×f)value(Q≈12,500)at x=0.02 than SrY_(2)O_(4).All Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited pure phase structures,although variations in crystal-plane spacings were *** ceramics are mainly composed of Sr-O,Y1-O,and Y_(2)-O octahedra,with the temperature coefficient of the resonant frequency(τ_(f))of the ceramic increasing with Y_(2)-O octahedral *** ceramic comprises uniform grains with a homogeneous elemental distribution,clear grain boundaries,and no obvious cavities at x=*** Sr_(1+x)Y_(2)O_(4+x)(x=0-0.04)ceramics exhibited good microwave dielectric properties,with optimal performance observed at x=0.02(dielectric constant(εr)=15.41,Q×f=112,375 GHz,and τ_(f)=-17.44 ppm/℃).The τ_(f) value was reduced to meet the temperaturestability requirements of 5G/6G communication systems by adding CaTiO_(3),with Sr_(1.02)Y_(2)O_(4.02)+2wt% CaTiO_(3) exhibiting ε_(r)=16.14,Q×f=51,004 GHz,andτf=0 ppm/℃.A dielectric resonator antenna prepared using Sr_(1.02)Y_(2)O_(4.02)+2wt%CaTiO_(3) exhibited a central frequency of 26.6 GHz,with a corresponding gain and efficiency of 3.66 dBi and 83.14%,***,Sr_(1.02)Y_(2)O_(4).02-based dielectric resonator antennas are suitable for use in 5G millimeter-wave band(24.5-27.5 GHz)applications.

关键词： millimeter wave microwave dielectric ceramics dielectric resonator antenna nonstoichiometric ratio

Negative enthalpy alloys and local chemical ordering:a concept and route leading to synergy of strength and ductility

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National science Review 2024年第4期11卷 172-184页

作者： Zibing An Tao Yang Caijuan Shi Shengcheng Mao Lihua Wang Ang Li Wei Li Xianmeng Xue Ming Sun Yifan Bai Yapeng He Fuzeng Ren Zhouguang Lu Ming Yan Yang Ren Chain-Tsuan Liu Ze Zhang Xiaodong Han Beijing key lab of Microstructure and Property of Advanced materials College of Materials Science &Engineering Beijing University of Technology Department of materials science and engineering City University of Hong Kong key laboratory of Partial Acceleration Physics& Technology Institute of High Energy PhysicsChinese Academy of Sciences Department of materials science &engineering Southern University of Science and Technology Department of Physics City University of Hong Kong State key laboratory of Silicon materials Department of Materials Science and Engineering Zhejiang University

Solid solutions are ubiquitous in metals and alloys. Local chemical ordering(LCO) is a fundamental sub-nano/nanoscale process that occurs in many solid solutions and can be used as a microstructure to optimize strength and ductility. However, the formation of LCO has not been fully elucidated, let alone how to provide efficient routes for designing LCO to achieve synergistic effects on both superb strength and ductility. Herein, we propose the formation and control of LCO in negative enthalpy alloys. With engineering negative enthalpy in solid solutions, genetic LCO components are formed in negative enthalpy refractory high-entropy alloys(RHEAs). In contrast to conventional ‘trial-and-error' approaches, the control of LCO by using engineering negative enthalpy in RHEAs is instructive and results in superior strength(1160 MPa) and uniform ductility(24.5%) under tension at ambient temperature, which are among the best reported so far. LCO can promote dislocation cross-slip, enhancing the interaction between dislocations and their accumulation at large tensile strains; sustainable strain hardening can thereby be attained to ensure high ductility of the alloy. This work paves the way for new research fields on negative enthalpy solid solutions and alloys for the synergy of strength and ductility as well as new functions.

关键词： negative enthalpy alloys local chemical ordering strength ductility dislocation

Boron nitride microribbons strengthened and toughened alumina composite ceramics with excellent mechanical,dielectric,and thermal conductivity properties

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Journal of Advanced Ceramics 2024年第4期13卷 496-506页

作者： Jilin Wang Dongping Lu Weiping Xuan Yuchun Ji Ruiqi Chen Shaofei Li Wenbiao Li Wenzhuo Chen Shilin Tang Guoyuan Zheng Fei Long Guangxi key laboratory of Optical and Electronic materials and Devices Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of ResourcesSchool of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004China key laboratory of New Processing Technology for nonferrous Metals and materials of Ministry of Education Guilin University of TechnologyGuilin 541004China School of materials science and engineering Peking UniversityBeijing 100871China Department of Civil and Environmental engineering The Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina

Aluminum oxide(Al_(2)O_(3))ceramics have been widely utilized as circuit substrates owing to their exceptional *** this study,boron nitride microribbon(BNMR)/Al_(2)O_(3)composite ceramics are prepared using spark plasma sintering(SPS).This study examines the effect of varying the amount of toughened phase BNMR on the density,mechanical properties,dielectric constant,and thermal conductivity of BNMR/Al_(2)O_(3)composite ceramics while also exploring the mechanisms behind the toughening and increased thermal conductivity of the fabricated *** results showed that for a BNMR content of 5 wt%,BNMR/Al_(2)O_(3)composite ceramics displayed more enhanced characteristics than pure Al_(2)O_(3)*** particular,the relative density,hardness,fracture toughness,and bending strength were 99.95%±0.025%,34.11±1.5 GPa,5.42±0.21 MPa·m^(1/2),and 375±2.5 MPa,*** values represent increases of 0.76%,70%,35%,and 25%,respectively,compared with the corresponding values for pure Al_(2)O_(3)***,during the SPS process,BNMRs are subjected to high temperatures and pressures,resulting in the bending and deformation of the Al_(2)O_(3)matrix;this leads to the formation of special thermal pathways within *** dielectric constant of the composite ceramics decreased by 25.6%,whereas the thermal conductivity increased by 45.6%compared with that of the pure Al_(2)O_(3)*** results of this study provide valuable insights into ways of enhancing the performance of Al_(2)O_(3)-based ceramic substrates by incorporating novel BNMRs as a second *** improvements are significant for potential applications in circuit substrates and related fields that require high-performance materials with improved mechanical properties and thermal conductivities.

关键词： boron nitride microribbons/aluminum oxide(BNMRs/Al_(2)O_(3))composite ceramics boron nitride microribbon(BNMR) spark plasma sintering(SPS) strengthening and toughening thermal conductivity

Single-atom alloys prepared by two-step thermal evaporation

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Nano Research 2024年第4期17卷 2808-2813页

作者： Honglin Wang Jing Li Meirong Huang Jizhe Cui Zhiying Cheng Rong Yu Hongwei Zhu State key lab of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China State key lab of Solid Waste Reuse for Building materials Beijing Building Materials Academy of Science ResearchBeijing 100041China

Single-atom alloys(SAAs)have gained significant attention due to their remarkable atomic utilization efficiency,interactions between single atoms(SAs)and metal supports,and free-atom-like electronic structure of dopant *** this work,we observed the formation of SAs in pre-deposited metal particles by a two-step thermal evaporation technique,thereby establishing the first instance of discovering SAAs by thermal *** discovery of SAAs by thermal evaporation extends the range of SAAs preparation methods to include this traditional synthetic technique,which offers convenience,cost-efficiency,and *** formation mechanism of SAAs prepared using this technique was elucidated by density functional theory *** was demonstrated that thermal evaporation can be utilized to prepare SAAs with multiple SAs,further highlighting its universal applicability.

关键词： single-atom alloys thermal evaporation density functional theory

Electrolyte-gated SrCoO_(x) FET sensor for highly sensitive detecting pH in extreme alkalinity solution

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Nano Research 2024年第4期17卷 3079-3086页

作者： Han Zhou Gaocan Qi Wenbin Li Yuhang Wang Zhihao Yuan School of materials science and engineering Tianjin Key Lab of Photoelectric Materials&Devicesand Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)Tianjin University of TechnologyTianjin 300384China

The pH monitoring is significantly important in chemical industry,biological process,and pollution ***,it remains a great challenge to measure pH in extreme alkalinity ***,we employ an electrolyte-gated field-effect-transistor(FET)strategy using non-stoichiometric SrCoO_(x) with rich oxygen-vacancy defects as channel materials for detecting extreme *** corresponding channel can provide effective oxygen-ion-migration sites for reversible transformation of OH-↔O_(2)-+H^(+)driven by electric *** resultant electrolyte-gated FET sensor exhibits a sensitive linear response to high concentrations of alkaline solution,1–20 ***,the sensor has the ability to directly indicate the pH values ranging from 14.0 to 17.0 in consideration of ion-activity coefficient *** work offers a great possibility for directly detecting base concentration as well as pH values in extreme alkaline solutions.

关键词： field-effect-transistor(FET) pH sensor extreme alkaline solution SrCoO_(x) oxygen-ion migration