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Morphology and orientation relationship of VC precipitates in HSLA steel

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Journal of University of Science and Technology Beijing 2006年第5期13卷 420-423页

作者： Shijian Yan Xiaoping Liu wenhuai tian Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

The morphology and distribution of VC precipitates in HSLA steel as well as the orientation relationship between VC precipitate and α-Fe were studied by transmission electron microscopy （TEM）. The chemical composition of the VC precipitate was analyzed qualitatively by using analytical electron microscopy （AEM） equipped with an energy dispersive spectrum （EDS） system. The VC precipitate is needle-like in shape with a size of about 10 nm in length and is homogeneously dispersed in the α-Fe matrix. The smaller lattice misfit along the 〈100〉 lattice direction of α-Fe matrix leads to VC precipitate forming with its long axes nearly parallel to the 〈100〉 lattice direction of α-Fe matrix. It is confirmed that the orientation relationship between VC precipitate and α- Fe is the ＂N-W＂ orientation relation by selected area electron diffraction （SAED） patterns.

关键词： vanadium micro-alloyed steels VC precipitation orientation relationship

Crystal defects formed in electroformed nickel liners of shaped charges

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Acta Metallurgica Sinica(English Letters) 2009年第5期22卷 383-391页

作者： Feng YANG wenhuai tian Chuanchao FENG Baosheng WANG Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China 210 Institute Beijing 100081 China

Two types of electroformed nickel liners of shaped charges were prepared by electroforming technique. X-ray diffraction （XRD）, transmission electron microscopy （TEM）, electron backscattering diffraction （EBSD） technique and high resolution electron microscopy （HREM） have been employed to investigate the crystal defects formed in electroformed nickel liners of shaped charges. The result shows that （100） fiber texture which is parallel to the grown direction exists in the electroformed nickel prepared by using direct current electroforming without any additives, and （111） fiber texture exists in the electroformed nickel prepared by using direct current electroforming with additives. The deposits prepared by using direct current electroforming possess columnar grain with an average grain size of 30 μm in width and 170 μm in length. The deposits prepared with additives are composed of a colony structures with grain size of about 29 nm, and a lot of crystal defects such as twins, antiphase boundaries and stacking faults have been observed in the electroformed nickel.

关键词： Electroformation Nickel Nanostructure Crystal defect Texture

Microstructure and penetration behavior of electroformed copper liners of shaped charges during explosive detonation deformation

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Journal of University of Science and Technology Beijing 2006年第1期13卷 73-77页

作者： Ailing Fan wenhuai tian Qi Sun Baoshen Wang Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China Taiyuan University of Science and Technology Taiyuan 030024 China 210 Institute Beijing 100081 China

The microstructure in the electroformed copper liners of shaped charges prepared with different electrolytes was studied by Scanning Electron Microscopy （SEM） and Electron Backscattering Kikuchi Pattern （EBSP） methods. SEM observations revealed the existence of columnar grains in electroformed copper liners of shaped charges formed by electrolyte without any additive and the average grain size is about 3 μm. When an additive is introduced to the electrolyte, the grains formed in the copper liners become equiaxed and finer. EBSP results show that the columnar grain grown during electroformation has the most preferential growth direction, whereas a micro-texture does not exit in the specimen prepared by electrolyte with the additive. Further, explosive detonation deformation experiments show that penetration depth is dramatically improved when the electroformed copper liners of shaped charges exhibit equiaxed grains.

关键词： electroformation additive microstructure explosive detonation deformation penetration

Oxidation behavior of niobized TiAl by plasma surface alloying

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Journal of University of Science and Technology Beijing 2008年第5期15卷 590-593页

作者： Dongdong Chen wenhuai tian Jian Wang Xiaoping Liu School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Research Institute of Surface Engineering Taiyuan University of Technology Taiyuan 030024 China

Plasma surface alloying of element Nb in TiAl-based alloys and the oxidation behavior were studied. The composition and microstructure of the surface alloyed layers were investigated by means of scanning electron microscopy （SEM）,energy dispersive X-ray analysis （EDX）,and X-ray diffraction （XRD）. The experimental results indicate that the diffusion layers are formed on the TiAl substrate during the plasma niobizing process. The result from oxidation resistance investigation shows that plasma niobizing greatly improves the oxidation resistance of TiAl compared with the untreated TiAl. The role of element Nb for improving the oxidation resistance is considered to be achieved by strengthening the activity of Al,which is induced by the plasma niobizing process.

关键词： TiAl alloys plasma niobizing oxidation resistance surface alloying

Charge and discharge curves:a unique reliable evidence for the electrochemical properties of LiCoO_2

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Journal of University of Science and Technology Beijing 2007年第5期14卷 473-476页

作者： Shijian Yan Jian Wang Lu Qi wenhuai tian Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China Department of Applied Chemistry Peking University Beijing 100871 China

X-ray diffraction （XRD）, the traditional characterization method to detect the electrochemical properties of LiCoO2, was doubted. The XRD patterns of three types of LiCoO2, with similar electrochemical properties, present differences. For the same type of LiCoO2, different XRD patterns were obtained when the sample preparing methods were different, because of preferred orienta- tion. The nonstandard method to prepare XRD powder samples can eliminate preferred orientation. The reliable evidence to detect electrochemical properties is still charge and discharge curves.

关键词： LiCoO2 X-ray diffraction (XRD) preferred orientation electrochemical properties

Ta-doped modified Gd2O3 film for a novel high k gate dielectric

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Journal of Materials Science & Technology 2019年第10期35卷 2305-2311页

作者： Shuan Li Yanqing Wu Guoling Li Hongen Yu Kai Fu Yong Wu Jie Zheng wenhuai tian Xingguo Li Department of Materials Physics and Chemistry University of Science and Technology BeijingBeijing 100083China Beijing National Laboratory of Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China College of Materials Science and Engineering Qingdao UniversityQingdao 266071China

Gadolinium oxide(Gd2O3) film has potential as a candidate gate dielectric to replace Hf O2. In this work,we provide a simple method by trace Ta(~1%) doping to significantly improve the dielectric properties of Gd2O3 film. And effects of annealing temperatures of Ta-doped Gd2O3(GTO) films are investigated in detail. Results show that GTO film annealed at 500℃ exhibits excellent performance as a novel gate dielectric material for integrated circuit, showing a small surface roughness of 0.199 nm, a large band gap of 5.45 e V, a high dielectric constant(k) of 21.2 and a low leakage current density(Jg) of 2.10 × 10^-3A/cm^*** properties of GTO films are superior to pure Gd2O3 films and these GTO films meet the requirements for next-generation gate dielectrics. In addition, impedance spectrum is first used to analyze the equivalent circuit of GTO based metal-oxide-semiconductor(MOS) capacitors, which represents a new insight to understand observed electrical behaviors.

关键词： Rare earth oxides High k film Magnetron sputtering Annealing temperature Gate dielectrics

Experimental investigation and thermodynamic assessment of the yttrium-hydrogen binary system

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Progress in Natural Science:Materials International 2018年第3期28卷 332-336页

作者： Kai Fu Xiaojing Jiang Yanru Guo Shuan Li Jie Zheng wenhuai tian Xingguo Li Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing National Laboratory of Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking University

A coupled experimental investigation and thermodynamic study of the yttrium-hydrogen(Y-H) binary system were carried out to provide more comprehensive and quantitative insights into the key thermodynamic properties of this system. Y-H system in the full range of H/Y = 0–3.0 was investigated by accurate pressure composition isotherm(PCI) measurement to provide credible phase equilibria information and thermodynamic *** phase boundaries obtained were in agreement with previous experimental data but with improved *** the guide of the crystal structures, all the solid phases were modelled using the three sublattice model. The Y-H phase diagram and thermodynamic parameters were calculated and assessed with the CALPHAD *** obtained results are in very good agreement with our experimental data and the published data reported in literature. The obtained thermodynamic database of Y-H system can be used to predict the hydrogenation behavior and decomposition temperatures of hydrides.

关键词： Rare earth Yttrium Hydrogen Pressure composition isotherm Phase diagram Thermodynamics

Ni-Al-Fe系中NiAl(Fe)金属间化合物的析出强化

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稀有金属材料与工程 2010年第3期39卷 460-463页

作者：冷文秀田文怀北京科技大学北京100083 中国石油大学北京102249

研究Ni-Al-Fe系中B2型金属间化合物NiAl(Fe)的硬度随时效时间的变化,同时测定时效处理后含析出相的NiAl(Fe)金属间化合物的屈服强度随温度变化。结果表明,在所有实验温度区域内,NiAl(Fe)化合物的屈服强度均远高于单相NiAl;析出相为体心... 详细信息

研究Ni-Al-Fe系中B2型金属间化合物NiAl(Fe)的硬度随时效时间的变化,同时测定时效处理后含析出相的NiAl(Fe)金属间化合物的屈服强度随温度变化。结果表明,在所有实验温度区域内,NiAl(Fe)化合物的屈服强度均远高于单相NiAl;析出相为体心立方结构的α-Fe相;在时效初期α-Fe相呈球状,过时效之后变成平行于有序基体{100}晶面的板条状。通过透射电镜观察还确定变形过程中位错滑移矢量为。虽然α-Fe析出相的硬度低于NiAl(Fe)基体,但由于α-Fe析出相对运动位错有较强的钉扎作用而使基体得到强化。

关键词： α-Fe析出相时效硬化显微结构 NiAl(Fe)金属间化合物

The Development of Fullerenes in Cosmetics from Domestic and Worldwide Patent Data

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China Detergent & Cosmetics 2022年第2期7卷 73-80页

作者： Gu Lingjun Shang Jingjing Li Guoqing Yu Hongmei tian wenhuai Chinese Academy of Inspection and Quarantine Cosmetic Tech CenterChina University of Science and Technology Beijing School of Materials Science and EngineeringChina

Fullerene is an excellent anti-aging raw material for cosmetic industry,which has strong free radical scavenging *** work on fullerene has been mostly focused on its applications and properties,but there are few studies on the patents regarding its application in ***,the development of fullerene in its application in cosmetics was analyzed by searching the patents regarding fullerene in cosmetic industry in the databases from China National Intellectual Property Administration and European Patent *** main technical fields of patents,the applicants and inventors,the publication date and the region were *** comparison was also conducted according to above aspects at home and *** was found that fullerene-containing cosmetics in China was generally consistent with the world *** started a little later than other countries in terms of time;there are quality problems worldwide,e.g.,the lack of technical *** patents mainly related to appearance or *** the second largest patent applicant country for fullerene-containing cosmetics in the world,China obviously has leading advantage in terms of *** the applicant regions being considered,fullerene industry giants such as Japanese Mitsubishi are the main *** to the late start of domestic enterprises,there is still a big gap with the world’s leading ***,in cosmetics industry,it can be said that domestic enterprises have taken the initiative when contrasted with traditional overseas brands.

关键词： development of fullerene patent cosmetics