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Bulk nanocrystalline W-ti alloys with exceptional mechanical properties and thermal stability

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Journal of Materials Science & technology 2022年第19期114卷 16-28页

作者： H.x.xue x.C.Cai B.R.sun x.Shen C.C.du x.J.Wang t.t.Yang S.W.xin t.d.Shen Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China CSSC 723rd Research Institute China State Shipbuilding Corporation LimitedYangzhou 225000China

Nanocrystalline(NC)W metals and alloys often exhibit higher radiation tolerance and strength than their coarse-grained ***,their thermal stability is low,making it difficult to achieve bulk NC W metals and alloys by consolidation using conventional techniques such as pressure-less sintering,hot-explosive-compaction sintering,and spark plasma *** we report the synthesis and mechanical properties of bulk NC W_(100-x)ti_(x)(x=10 at.%-30 at.%)alloys prepared by consolidating mechanically alloyed NC powders under a high-temperature/high-pressure *** 20 at.%-30 at.%ti largely improves the sinterability of NC W-ti alloy *** room-temperature microhardness and compressive yield strength of consolidated bulk NC W_(80)ti_(20) alloy are∼16.9 and 6.0 GPa,respectively,which are mainly caused by grain boundary strengthening and significantly higher than those of previously reported W and W *** ultimate compressive strength of bulk NC W_(80)ti_(20) measured between 900 and 1100°C deceases with increasing *** behavior can be explained by the activation of Rachinger grain boundary *** grain growth is observed in bulk NC W_(80)ti_(20) after compression at 1000°*** calculation suggests that it is the segregation of ti at grain boundaries that decreases the specific grain boundary free energy and makes the NC W_(80)ti_(20) alloy thermodynamically stable.

关键词： Nanocrystalline W-ti alloys Segregation Grain boundary energy Strength Hardness

REMOVE INCLUSIONS FROM ALUMINUM MELt INELECtROMAGNEtIC FIELd

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Acta Metallurgica Sinica(English Letters) 2000年第5期13卷 1068-1074页

作者： t.x.Li Z.M.xu B.d.sun d.Shu Y.H.Zhou School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200030China

Electromagnetic separation of non-metallic inclusions from Al-Si melt is studied by theoretical analysis and experiments on self-designed electromagnetic separation apparatus. Metallographs and LECO Image Analysis System were used to analyze the content of alumina in aluminum alloy before and after electromagnetic separation. It is seen that removal effciency increases with the increase of electromagnetic force (EMF) and diameter of inclusion particles while decreases with the increase of melt velocity and height of separator. All alumina particles with diamete of 14μm have been removed successfully from the melt.

关键词： aluminum melt alumina particle electromagnetic separation removal efficiency

Capacitance of High-Voltage Coaxial Cable in Plasma Immersion Ion Implantation

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Journal of Materials Science & technology 2001年第1期17卷 41-42页

作者： x.B.tian L.P.Wang d.t.K.Kwok B.Y tang P.K.Chu department of Physics&Materials Science City University of Hong KongHong KongChina

Plasma immersion ion implantation (PIII) is an excellent technique for the surf see modification of complex-shaped components. Owing to pulsed operation mode of the high voltage and large slew rate, the capacitance on the high-voltage coaxial cable can be detrimental to the process and cannot be ignored. In fact, a significant portion of the rise-time/fall-time of the implantation voltage pulse and big initial current can be attributed to the coaxial cable.

关键词： surface modification ion implantation high voltage mode of

EFFECtS OF HddR PROCESS ON StRUCtURE ANd MAGNEtIC PROPERtIES OF Nd(Fe,ti)_(12)N_δ PREPAREd BY MECHANICAL ALLOYING

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Acta Metallurgica Sinica(English Letters) 1998年第1期11卷 68-78页

作者： B.ZCui x.K.sun x.G.Zhao W.Liu Q.F.xiao t.Zhao Z.d.Zhang Y.C.Sui Chinese Acad of Sciences Shenyang China

the effects of the hydrogenation-disproportionation-desorption-recombination (HddR) process on the structure and the magnetic properties of the mechanical alloying (MA) prepared Nd8Fe84 ti8 alloy and its nitride counterpart have been studied in detail. It has been found that Nd(Fe, ti)12Hδ is formed in the temperature range from 300 to 550°℃. the disproportionation is ready to start at 550°℃ and is complete at 960°℃.the desorption and the recombination are almost synchronized. the phase of Nd(Fe,ti)7 is formed at 750°℃ during the HddR treatment. With increasing temperature of HddR process, the metastable structure of tbCu7 type is gradually transformed into the structure of thMn12 type. the intrinsic coercivity and the maximum magnetic energy product increase with increasing temperature of HddR process.

关键词： Nd(Fe ti)_(12)N_δ compound,magnetic property hydrogenation

Achieving Reliable CoSb_(3) based thermoelectric joints with low contact resistivity using a high-entropy alloy diffusion barrier layer

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Journal of Materiomics 2022年第4期8卷 882-892页

作者： Z.sun x.Chen Juncheng Zhang Huiyuan Geng L.x.Zhang State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China

Skutterudite(SKd)thermoelectric materials have high conversion efficiency,great mechanical proper-ties,and economical practicability in the medium temperature range(500e550C).they need to bejoined with metal electrodes to form a thermoelectric power generation device during ***,high contact resistivity,severe element diffusion,and large coefficient of thermal expansionmismatch are main obstacles for their *** address these issues,a FeCoNiCrMo high-entropyalloy diffusion barrier layer was designed and prepared using an arc smelting method in this *** heating temperatures on the microstructure and properties of the bonded joints were *** maximum shear strength was 21.6 Mpa and the corresponding reaction layer thickness,contactresistivity were 3.77 mm,1.8 mUcm2 respectively at 600C,40 MPa,10 *** strength dropped downto 18.8 MPa and the contact resistivity increased to 4.2 mU cm2 after aging for 640 *** modelwas established and it predicted that the contact resistivity would keep lower than 6.5 mU cm2(300 h,100 days)and 11 mU cm2(8760 h,1 year)and the reaction layer thickness would not exceed 25 mm(2400 h,100 days)and 45 mm(8760 h,1 year).

关键词： High-entropy diffusion barrier layer Skutterudite diffusion bonding Microstructure Shear strength Contact resistivity

Homologous CoS2 interface with directed electron transfer and strong chloridion repulsion for efficient seawater oxidation

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Science China Chemistry 2025年

作者： Yuan tian Jiang-Bo Chen Jie Ying Ge tian Yu-xuan xiao Yi Lu Si-Ming Wu Wei Geng Ling Shen xiao-Yu Yang State Key Laboratory of Advanced technology for Materials Synthesis and Processing and School of Materials Science and Engineering and Shenzhen Research Institute & Laoshan Laboratory Wuhan University of Technology School of Chemical Engineering and technology Sun Yat-Sen University National Energy Key Laboratory for New Hydrogen-Ammonia Energy technologies Foshan xianhu Laboratory

Seawater electrolysis is a highly promising method to produce high energy density hydrogen,especially in dry areas that have scarce freshwater ***,application of seawater electrolysis is confronted by two major problems associated with catalysts employed for the anodic oxygen evolution reaction （OER） including the competitive hypochlorite evolution reaction（HCER） and strong chloridion （Cl–） triggered *** studies aimed at overcoming these problems,a facile method has been developed to synthesize a homologous CoS2heterojunction as an OER *** to a difference in work functions at the interface and increased electron density,this material has directed electron transfer and strong chloridion repulsion properties,*** have shown that CoS2achieves low overpotentials of 289 and 322 mV at 10 mA cm-2current density in respective alkaline （1 M KOH） and alkaline simulated seawater ***,the outstanding stability of CoS2is reflected in a negligible decline in activity during promotion of the OER for 100 *** of density functional theory calculations reveal that the homologous CoS2heterojunction promotes directed electron transport for optimizing adsorption/desorption of reactive species and heightens the Cl-adsorption energy for strongly repulsing Cl-,phenomena that enhance OER performance in alkaline simulated seawater.

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Embedding laser-generated Cdte nanocrystals into ultrathin ZnIn_(2)S_(4) nanosheets with sulfur vacancies for boosted photocatalytic H_(2) evolution

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Journal of Materials Science & technology 2023年第35期166卷 113-122页

作者： Z.G.tai G.t.sun x.H.Zhang x.B.Yang t.Wang Z.Y.Fang Q.Ye L.C.Jia H.Q.Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Research&development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China School of Materials Science and Engineering Shaanxi Normal UniversityXi’an 710119China

to suppress the inner charge recombination and inject vast electrons,Cdte nanocrystals are embedded into ultrathin ZnIn_(2)S_(4) nanosheets to construct ZnIn_(2)S_(4)/Cdte heterostructures,where the nanocrystals are generated by a laser irradiation *** optimal ZnIn_(2)S_(4)/Cdte heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the ZnIn_(2)S_(4)-based photocatalysts with-out noble *** enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur *** strong electron coupling effect,which is verified by density functional the-ory(dFt)calculations,impels the photo-generated electrons transfer from Cdte to ZnIn_(2)S_(4),boosting the charge ***,the sulfur vacancies existing in ZnIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the H_(2) generation *** addition,the ZnIn_(2)S_(4) base and the ZnIn_(2)S_(4)/Cdte heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic *** research provides new insights into the regulation of charge transfer through embedding nanocrystals.

关键词： Photocatalysis Hydrogen evolution Laser irradiation Heterostructure Sulfur vacancies

Correlation between microstructure and mechanical properties of columnar crystals in the directionally solidified Mg-Gd-Y-Er alloy

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Journal of Magnesium and Alloys 2022年第3期10卷 806-818页

作者： d.R.Fang S.S.Zhao x.P.Lin t.Chai Y.Kuo H.sun Y.dong School of Materials Science and Engineering Northeastern UniversityNo.11Alley 3Wenhua RoadHeping DistrictShenyangChina School of Resources and Materials Northeastern University at QinhuangdaoQinhuangdao 066004China

the Mg-4.58Gd-0.45Y-0.01 Er alloys with different volume fractions of columnar crystals in hard orientation(orientation factor ofbasal plane slip system is less than 0.2)were prepared by changing the pulling rate to regulate the crystal growth *** tests were performed on the Mg-4.58Gd-0.45Y-0.01 Er alloy at room temperature,and the structure after deformation was investigated by electron backscatter diffraction(EBSd).Subsequently,the strengthening mechanism of columnar crystals in hard orientation was *** results show if orientation factors ofbasal plane slip system of columnar crystals are all greater than 0.4(soft orientation),the alloy has low yield strength σ_(s)(64 MPa),but great work hardening ability,and ultimate tensile strength σ_(b) and elongationδare 114 MPa and 37.3%,*** orientation factors ofbasal plane slip system of columnar crystals are all less than 0.2(hard orientation),the alloy has high strength(σ_(s),125 MPa),but poor plasticity(δ,6.32%).If the"hard orientation"and the"soft orientation"columnar crystals are arranged alternately along the direction perpendicular to the crystal growth,the alloy has both superior strength(σ_(s),102 MPa)and excellent plasticity(δ,22.5%)at room *** improved comprehensive mechanical property can be attributed to two *** the one hand,the"hard orientation"columnar crystals can prevent the"soft orientation"crystals deforming,so the strength is *** the other hand,the"hard orientation"columnar crystals themselves can withstand a certain amount of deformation to retain appropriate plasticity.

关键词： directional solidification Mg-Gd-Y-Er alloy Hard orientation Mechanical prop

电聚合苯胺改性碳纤维海洋电极电化学性能及其电场响应研究

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中国海洋大学学报（自然科学版） 2025年第1期55卷 118-129页

作者：田翔孙久哲付玉彬中国海洋大学材料科学与工程学院山东青岛266100

本文应用碳酸氢铵弱碱性溶液作为电解质电化学原位聚合苯胺制备聚丙烯腈基碳纤维海洋电极,研究其电化学性能与电场响应性能。结果表明,碳纤维表面生成还原态聚苯胺并出现特征氧化还原峰;交流阻抗谱表明改性电极表面等效电路增加了膜电... 详细信息

本文应用碳酸氢铵弱碱性溶液作为电解质电化学原位聚合苯胺制备聚丙烯腈基碳纤维海洋电极,研究其电化学性能与电场响应性能。结果表明,碳纤维表面生成还原态聚苯胺并出现特征氧化还原峰;交流阻抗谱表明改性电极表面等效电路增加了膜电容和膜电阻,电场响应由纯电容耦合改变为电容电阻共同作用的混合机制,有利于低频低强度信号的响应。在电场响应测试中,改性电极电位漂移量达0.66 mV/d;能够较好响应10 mV,10 mHz的低频率低强度电场信号;线性度最小值为0.072%。水流冲刷4h后聚苯胺膜质量损失为6.30%,相比于盐酸溶液电聚合制得的聚苯胺膜(质量损失7.55%)具有更好的结合力。该海洋电极可望成为新一代低成本、高性能电场传感器。

关键词：碳纤维电极聚苯胺碳酸氢铵电化学性能海洋电场响应

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