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Effects of processing conditions on Hydrothermal Synthesis of K_(0.5)Bi_(0.5)TiO_3 Nano-Powders

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稀有金属材料与工程 2006年第A03期35卷 561-563页

作者： Hongyan Miao Min Dong Guoqiang Tan Jia Li School of Material Science and Engineering Shaanxi University of Science and Technology Xianyang 712081 China

Potassium bismuth titanate nanosized powders were prepared by the hydrothermal method using Ti(C_4H_9O)_4 and Bi(NO_3)_3·5H_2O as raw materials in alkaline *** phase composition,particle size and morphology of the powders were studied by XRD and TEM *** results showed that the powders were well crystallized and *** crystal phase of the powders was K_(0.5)Bi_(0.5)TiO_3 with the grain size of about 50 nm～100 *** temperature and alkaline concentrations had great effects on the phase composition and morphology of the resultant *** K_(0.5)Bi_(0.5)TiO_3 powders could be synthesized at 170℃～180℃with KOH concentration of 8 mol/L～12 mol/L.

关键词： processing conditions hydrothermal synthesis potassium bismuth titanate powders

Magneto-Caloric Effect of Gd5Si2Ge2Compounds under Different processing conditions

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Journal of Rare Earths 2004年第z1期22卷 76-78页

作者： Zeng Hong Yue Ming Niu Peili Zhang Jiuxing Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of TechnologyBeijing 100022 China

The magneto-caloric effect of Gd5 Si2Ge2 compounds produced by various techniques is investigated in terms of their magnetization behaviors in the magnetic field from 0 to 2.0 *** studied materials include arc-melted, annealed and sintered *** results demonstrate that the Gd5Si2Ge2 alloys obtained under different processing conditions possess distinct magneto-caloric effect due to their various *** annealing treatment can enhance the magneto-caloric effect of the alloy *** the sintered alloy bears relatively lower value of magnetic entropy change ( △ SM) than arc-melted *** magnetic entropy change of the annealed Gd5 Si2Ge2 alloy arrives the arrives the maximum value of - △SM = 15.29 J· kg-1· K-1 for magnetic field change under 2.0 T in the present work.

关键词： magneto-caloric effect processing conditions Gd5Si2Ge2 magnetic entropy change

Research on processing conditions of CBS Transparent Glass-ceramics

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Research on Processing Conditions of CBS Transparent Glass-c...

Mathematical Modelling and Numerical Simulation of the Non-isothermal In-mold Vulcanization of Natural Rubber

第八届中国功能材料及其应用学术会议

作者： WANG Yi-min ZHANG Hong-bo SU Chun-hui WEI Qin-lei Changchun University of Science and Technology Jilin Vocational College of Industry and Technology Jilin Teacher's Institute of Engineering and Technology

ISBN: (纸本)9783037859698

On the basis of experimental verification,the optimum processing conditions of CaO-BO-SiO(CBS) system transparent glass-ceramics were *** of main raw powders(wt%) was:CaO 38%,SiO 40%,BO 12%.The precursor glasswas prepared by melting method and annealed at 560℃for2h and cooled to room temperature at a speed of 5℃/*** best nucleating agent is *** appropriate heat treatment regimeto precursor glass was determined to be 2h at 600℃ for nucleation and 3h at780℃ for *** this condition,the transmittion of glass-ceramics at the range of visable light is72%in average and Sm keep good luminescence property doped in this host material.

关键词： Transparent Glass-ceramics processing conditions

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cnki会议

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Chinese Journal of Polymer Science 2015年第3期33卷 395-403页

作者： Dan-hui Wang Qi Dong 贾玉玺 Key Laboratory for Liquid-Solid Structural Evolution & processing of Materials (Ministry of Education) Shandong University

According to the vulcanization kinetic equation of natural rubber （NR） established in the isothermal situation, the numerical computation expression of the degree of cure under non-isothermal condition is constructed by means of incremental method. The description of non-isothermal in-mold vulcanization process is carried out by the finite element method. The mold-opening time, the rubber and mold temperatures, the degree of rubber cure and its distribution characteristics are numerically analyzed, by changing the key formulas and parameters in the process including the temperature of curing medium, the concentration of 2-mercaptobenzothiazole, the heat transfer manner of mold side, and the convective heat transfer coefficient of heating boundary. The quantitative results will help engineers to design proper formulas and optimize processing conditions.

关键词： Natural rubber Non-isothermal vulcanization Degree of cure processing conditions Finite element simulation.

Nickel release rate of 18KW gold alloy for ornaments

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Rare Metals 2013年第1期32卷 33-39页

作者： Jun-Ping Yuan Wei Li Wen-Ming Liu Department of Materials Science and Engineering Jinan University Jewelry Institute of Guangzhou Panyu Polytechnic

Nickel is widely used as a bleaching element in white gold alloys, but it is a potential allergen. In this paper, a popular 18 KW gold alloy, often called ＂safe nickel,＂ was chosen as the experimental material; its nickel release rates under six different processing conditions were evaluated according to the EN1811 standard. The results reveal that both the surface processing method and heat treatment technology significantly affect the nickel release rate. A coarse surface releases more nickel ions than a smooth surface. The sample normalized at 700 ~C in the single region has a lower nickel release rate than the one treated at 550 ~C in the two-phase phase region, while high temperature normalizing at 800 ~C will accelerate it. All the measured nickel release rates of the experimental material under various processing conditions exceed the permitted threshold value in the Nickel Directive, which indicates that there exists the potential risk of nickel- induced allergy when it is used to make jewelries, espe- cially for piercing types.

关键词： 18 KW Gold alloy Jewelry Nickel releaserate Nickel Directive processing conditions

Preparation of a High-Performance Si_3N_4 Ceramic Using Self-Reinforcing Technology

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High Technology Letters 1997年第2期3卷 84-88页

作者：罗学涛 Advanced Materials Institute Wuhan University of Technology Wuhan 430070 P. R. China

The self-reinforced Si_3N_4 ceramics which contain Y_2O_3 and La_2O_3 additives have been prepared by hot-pressing. Under the optimum processing conditions, this material has the flexural strength of 960～1050MPa and the fracture toughness of 11.17～12.74MPa·m^(1/2) at room-temperature, and 720～780MPa and 22～24MPa·m^(1/2) at 1350℃. The effects of heat ing rate, sintering temperature, and holding time on the microstructures and mechanical properties are investigated. The experimental results show that an appropriate β-Si_3N_4 grain size and homogeneous microstructure can be obtained under the conditions of a heating rate of 10℃/min, sintering temperature of 1800℃, and holding time of 1h, which are advantageous to enhancing the mechanical properties. Crack deflection in large rodlike β-Si_3N_4 grains is a principle source of toughening.

关键词： Si_3N_4 Self-reinforcing technology processing conditions Microstructure Mechanical properties

高压成型聚乳酸/聚乳酸-乙醇酸共聚物/羟基磷灰石复合多孔支架的颅骨修复研究

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高压成型聚乳酸/聚乳酸-乙醇酸共聚物/羟基磷灰石复合多孔支架的...