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Enhancement of comprehensive properties of Nb–Si based in-situ composites by Ho rare earth doping

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Rare metals 2024年第9期43卷 4508-4520页

作者： Wei Wei Qi Wang Rui-Run Chen Chao-Wen Zheng Yan-Qing Su National key laboratory for Precision Hot Processing of metals School of Materials Science and EngineeringHarbin Institute of Technology

This study examines the microstructure,mechanical properties （with a focus on room-temperature toughness）, and oxidation resistance of Ho-doped NbDSi based in-situ composites. The base alloy consists of the coarse primary Nb5Si3phase and the Nb5Si3+Nbss （Nb solid solution） eutectic cells. Ho doping influences the solidification path. When the Ho doping is higher than0.2 at%, the alloys transform into eutectic alloys. Ho can be solid-solved in trace amounts in the Nbss phase. However, most of Ho forms a stable Ho oxide phase, which alleviates oxygen contamination problem to some ***, the interface separation between Ho oxide and other phases reduces the plastic deformation ***, with 0.4 at%Ho doping, the KQvalue is18.03 MPa·m1/2, which is 31.1%higher than that of the base alloy. The strength of the Ho-doped alloys does not deteriorate with an increase in toughness. However, the large network-like Ho2O3in the 0.8Ho alloy causes a decrease in toughness and strength. In addition, the Ho oxide phase effectively blocks the inward oxygen *** 0.8 at%Ho doping, the oxidation mass gain per unit area is 10.16 mg·cm2, which is 39.7%lower than that of the base alloy.

关键词： Ho Microstructure Nb–Si based composites Properties Rare earth elements

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

Dielectric and energy storage properties of PbO–SrO–Nb_(2)O_(5)–Na_(2)O–Si thin films by annealing

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Rare metals 2024年第1期43卷 351-355页

作者： Fei-Hu Tan Qing-Meng Zhang Feng Wei Hong-Bin Zhao Xiao Zhang Jun Du State key laboratory of Advanced materials for Smart Sensing General Research Institute for Nonferrous MetalsBeijing 100088China Advanced Electronic materials Institute General Research Institute for Nonferrous MetalsBeijing 100088China

Dielectric and energy storage properties of PbOSrO-Na_(2)O-Nb_(2)O_(5)-SiO_(2)(PSNNS) thin films with annealing temperature from 700 to 850 ℃ were investigated by measuring their capacitance-electric filed curve and hysteresis *** results show that the highest dielectric constant and energy density are 81.2 and 17.0 J·cm^(-3),respectively,which is obtained in the sample with annealing temperature of 800 ℃.Annealed from 700 to800 ℃,the dielectric constant and energy storage performance of PSNNS films are continuously ***,with annealing temperature up to 850 ℃,their dielectric constant decreases,which might be related with the removal of interfacial defects as a function of annealing *** is one of the causes of space charge phenomenon,resulting in the increase in dielectric ***,the micro structure analysis by X-ray diffraction(XRD) and transmission electron microscope(TEM) indicates that the change of crystallization phase and interfacial polarization takes responsibility to the results.

关键词： Thin film Pulse laser deposition Annealing temperature Energy storage density

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

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

Long-wave infrared emission properties of strain-balanced InAs/In_(x)Ga_(1-x)As_(y)Sb_(1-y)type-Ⅱsuperlattice on different substrates

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Rare metals 2024年第7期43卷 3194-3204页

作者： Chao Shi Xuan Fang Hong-Bin Zhao Deng-Kui Wang Xi Chen Dan Fang Dong-Bo Wang Xiao-Hua Wang Jin-Hua Li State key laboratory of High Power Semiconductor Lasers School of PhysicsChangchun University of Science and TechnologyChangchun 130022China State key laboratory of Advanced materials for Smart Sensing China General Research Institute for Nonferrous MetalsBeijing 100088China Department of Opto-Electronic Information science School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic *** the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic *** this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates *** grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'***,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more *** addition,the optical properties of superlattices grown on different substrates are discussed *** of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared ***,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.

关键词： Photoluminescence Alloy compositions fluctuations InAs(Sb)/In_(x)Ga_(1-x)As_(y)Sb_(1-y) Type-Ⅱsuperlattice Substrate

Selective leaching of calcium from mechanically activated mixed rare earth concentrate

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Journal of Rare Earths 2024年第6期42卷 1149-1156,I0006页

作者： Jiang Liu Bingxue Chen Yuanqi Feng Yijun Cao Yukun Huang Yuan Shi Meng Li Zhongyuan Critical metals laboratory School of Chemical EngineeringZhengzhou UniversityZhengzhou450001China State key laboratory of Advanced Processing and Recycling of nonferrous metals Lanzhou University of TechnologyLanzhou730050China

The loss of rare earths(REs)takes place during the pre-decalcification process of mixed rare earth *** an effort to reduce such RE loss,a novel idea to improve the leaching selectivity of Ca to REs by applying selective mechanical activation was ***,regarding the key minerals affecting the leaching selectivity of Ca to REs,the differences in the mechanical activation behaviors of CaF_(2) and REFCO_(3) were studied,and we find that the lattice strain of CaF_(2) increases from 0.21%to 0.42%,whereas that of REFCO_(3) increases from 0.31%to 0.40%.Notably,CaF_(2) demonstrates a larger lattice strain than REFCO_(3),indicating greater mechanical activation energy storage and higher leaching ***,the HCl leaching process was studied.A significant leaching selectivity of Ca to REs,from 21.6 to 35.1,is achieved through mechanical *** Ca leaching rate reaches 80.7%when the RE loss is 2.3%in the activated *** study provides an novel approach for achieving selective extraction of specific components via mechanical activation pretreatment.

关键词： Mixed rare earth concentrate Pre-decalcification Selective mechanical activation Selective leaching

Properties and microstructure of copper–titanium alloys with magnesium additions

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Rare metals 2024年第5期43卷 2290-2299页

作者： Lue Huang Li-Jun Peng Jiang Li Xu-Jun Mi Gang Zhao Guo-Jie Huang Hao-Feng Xie Yi-Cheng Cao Wen-Jing Zhang Zhen Yang State key laboratory of nonferrous metals and Processes GRINM Group Co.Ltd.Beijing 100088China GRIMAT engineering Institute Co. LtdBejing 101407China School of materials science and engineering Northeastern UniversityShenyang110000China General Research Institute for nonferrous metals Beijing 100088China China Academy of Space Technology Beijing 100094China China nonferrous metals Mining Group(Tianjin)Co.Ltd Tianjin 3001llChina

The volume fractions and morphology of precipitates in precipitation-strengthened Cu-Ti alloys,which precipitate mainly as continuous and discontinuous precipitates,are important for the application of the *** study employed hardness and electrical conductivity tests transmission electron microscopy(TEM),atom probe tomography(APT),and first-principles calculations to demonstrate that the addition of Mg is effective for accelerating nanosized continuousβ'-Cu_(4)Ti precipitation as well as for suppressing the precipitation of coarse lamellar discontinuousβ-Cu_(4)Ti precipitates along the grain boundaries,resulting in Cu-Ti alloys with high yield strength and good electrical *** results showed that the continuous precipitation ofβ'-Cu_(4)Ti was accelerated by the Mg additions,which reduced the supersaturation of the matrix,thereby reducing the chemical driving force for the discontinuous *** the other hand,Mg additions increased the mismatch between the discontinuousβ-Cu_(4)Ti precipitates and matrix decreased the nucleation rate of the discontinuous precipitates,and increased the spacing of the discontinuous precipitation layer,resulting in a lower growth rate of the discontinuous ***,the addition of Mg to Cu-Ti alloys enhances the strength and improves the resistance to over-ageing.

关键词： Cu-Ti-Mg alloy Precipitation hardening Discontinuous precipitation Continuous precipitation Microstructure formation mechanism

Vanadium nitride quantum dots@carbon skeleton anode material synthesized via in situ oxidation initiation strategy

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Tungsten 2024年第3期6卷 561-573页

作者： Yi-Han Fu Yuan-You Peng Lei Zhao Tian-Qi He Mei-Mei Yuan Hao Dang Rui Liu Fen Ran State key laboratory of Advanced Processing and Recycling of Non-Ferrous metals School of Materials Science and Engineering Lanzhou University of Technology

Vanadium nitride（VN） has received significant attention as a potential negative electrode material due to its remarkable theoretical and physical ***,the electrochemical performance needs to be improved due to its low specific surface area and the issue of being easily dissolved in *** have shown that the composite structure of carbon-coated nano sc ale VN particles could significantly increase the specific surface area of VN,and more importantly,and the carbon matrix can effectively restrain the dissolution of VN particles in the electrolyte,thereby improving its chemical and electrochemical performance,including specific capacity and cycling ***,VN quantum dots are synthesized and protected by uniformly coating the carbon skeleton on its surface via an in situ strategy of oxidation initiation,which initiates dopamine polymerization,forming a crystalline complex of polydopamine and *** heat treatment,the product is a composite material with VN quantum dots embedded in the amorphous carbon *** resulting smallsized and crosslinked carbon particles formed a graded pore structure,more reasonable channels provided for electrolyte ions transport *** the composite material was used as the negative electrode material for supercapacitors,it exhibits the specific capacity of 391.9 F·g-1at a current density of 0.5 A·g-1and excellent capacity retention rate of 83.6% after *** synthesis method of this quantum dot could be applied to other metal compounds and has potential applications in catalysis,environmental protection,and other fields.

关键词： In situ initiation Vanadium nitride Quantum dots Anode Supercapacitors