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Relationship between Leucite Content and Compressive Strength of K_2O-Al_2O_3-SiO_2 System Dental Glass Ceramics

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Journal of wuhan university of technology(materials science) 2009年第1期24卷 72-74页

作者：张飚钱法汤 key laboratory of Oral Biomedical Engineering of Ministry of Education Wuhan University

Relationship between leucite content and compressive strength of K2O-Al2O3-SiO2 sys-tem dental glass ceramics were investigated. 10 groups of feedstock powder with different composi-tions were treated according to the same thermal treatment system of leucite micro-crystallization reported in some primary studies. The products of each group were analyzed by X-ray diffractometer, polaring microscope and scanning electronic microscope （SEM）, and then the compressive strength was tested by a material testing machine. A direct proportion was found between leucite content and the compressive strength when leucite content was less than 50 vol%, and compressive strength de-creased with the increasing of leucite micro-crystals when leucite content was more than 50vol%, The leucite content has a notable influence on the compressive strength of K2O-Al2O3-SiO2 system dental glass ceramics.

关键词： leucite content compressive strength glass ceramics

Spark Effect on the Densification of SiCp/Al Composites by SPS

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Journal of wuhan university of technology(materials science) 2006年第1期21卷 72-75页

作者：顾晓峰 state key laboratory of advanced technology for materials synthesis and processing Wuhan University of TechnologyWuhan 430070China

SiCp/ Al composites containing high volume fraction of SiC particles were fabricated by spark plasma sintering （SPS）. and their thermophysical properties, such as thermal conductivity （TC） and *** of thermal expansion （CTE）, were characterized. The electric field in the vacuum column was calculated and the generation condition of the spark was analyzed. Spark can be generated by a low current if the cavity in the green body is large enough. A high relative density of the composites was successfully achieved through the optimization of sintering parameters. The measured TCs of the SiCp/ Al composites fabricated by SPS are higher than 195 W/m ·K.

关键词： spark plasma sintering SiCp/ Al composites thermal conductivity coeffwient of thermal expansion densification

Photocatalytic Degradation of Rhodamine B Dye with MWCNT/TiO_2/C_(60) Composites by a Hydrothermal Method

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Journal of wuhan university of technology(materials science) 2011年第1期26卷 65-69页

作者：史晓亮 School of Mechanical and Electronic Engineering Wuhan University of Technology state key laboratory of advanced technology for materials synthesis & processing Wuhan University of Technology

Multi-walled carbon nanotube （MWCNT）/TiO2/C60 composite catalysts were prepared by hydrothermal method. TiO2 was deposited on the MWCNT surface. Their photocatalytic activities for degradation of Rhodamine B dye were studied. X-ray diffraction, field emission transmission electron microscopy, ultraviolet-visible light absorption spectrum and photoluminescence spectrum were carried out to characterize the composite catalysts. The results indicated that MWCNTs and C60 could greatly enhance the photocatalytic activity of TiO2.

关键词： semiconductors chemical synthesis optical properties surface properties

Micro-alloying of yttrium in Zr-based bulk metallic glasses

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Progress in Natural science:materials International 2011年第1期21卷 46-52页

作者： Wei-jie PENG,Yong ZHANG state key laboratory for advanced Metals and materials, university of science and technology Beijing,Beijing 100083,china state key laboratory for advanced Metals and materials University of Science and Technology Beijing Beijing 100083 China

The effect of yttrium addition on the glass-forming ability(GFA) and mechanical properties of the Zr-based (Zr0.525Al0.1Ti0.05Cu0.179Ni0.146)100-xYxand(Zr0.55Al0.15Ni0.1Cu0.2)100-xYx(x=0,0.2,0.4 0.6,1,2) alloys was ***-alloying of 0.6%yttrium enhances the room temperature ductility as well as the GFA of the Zr-based *** mechanism of enhancing the GFA and room temperature ductility was *** is indicated that proper yttrium addition stabilizes the undercooled liquid by means of forming lots of ordered clusters,thus improving the GFA and the room temperature ductility.

关键词： micro-alloying glass-forming ability Zr-based alloys yttrium

MEAM Potential with Angular Dependence for TiAl

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Rare Metals 2001年第1期20卷 13-17页

作者： Xiaodong Ni, Xitao Wang, Guoliang Chen (Physics Department, university of science and technology Beijing, Beijing 100083, china state key laboratory for advanced Metals and materials, university of science and technology Beijing, Beijing 100083, china) 北京科技大学新金属材料国家重点实验室北京 100083 北京科技大学北京 100083

The modified embedded atom method (MEAM) is an empirical extension of the embedded atom method (EAM) that includes angular forces. By fitted to the lattice constants, the cohesive energy, the APE (anti-phase boundary) energy, and the vacancy formation energy of TiAl, an accurate MEAM potential is obtained for the TiAl system with L10 structure. The calculation results of the properties of TiAl are in good agreement with experiments and the results of first principle (F.P.) calculations.

关键词： embedded atom method TiAl alloy angular dependence potential intermetallics

Microstructure and Mechanical Properties of TiB_2-Al_2O_3 Composites

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Journal of wuhan university of technology(materials science) 2011年第4期26卷 696-699页

作者：刘国玺张金咏 The Ningbo Branch of Ordnance science Institute of china state key laboratory of advanced technology for materials synthesis and processing Wuhan University of Technology

Effects of Al2O3 and Ni as the additives on the sinterability, microstructure and mechanical properties were systematic studied. The experimental results show that only a relative density about 96.2% of hot-pressing TiB2-30%Al2O3 can be attained due to the plate-like TiB2 particle and its random orientation and excessive Al2O3 grain growth. When sintering temperature is higher than 1 700 ℃, TiB2 grain growth can be found, which obvious improves flexural strength of TiB2 matrix but decreases toughness. It seems that mechanical properties of TiB2-Al2O3 composites are mainly depended on relative density besides grain growth. otherwise, they will be determined by relative density and TiB2 matrix strength together. Anyway, Al2O3 addition can weaken the grain boundary and thus improve the toughness of the materials. A flexural strength of 529 MPa, Vickers hardness of 24.8 GPa and indentation toughness of 4.56 MPa·m1/2 can be achieved inTiB2-30vol% Al2O3.

关键词： TiB2-Al2O3 pressureless sintering microstructure mechanical properties

A Modified Integrated Model of the Internal Structure of Chinese Cultured Pearls

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Journal of wuhan university of technology(materials science) 2011年第3期26卷 510-513页

作者：马红艳 key laboratory of Nonferrous Metals and New Material processing technology Ministry of EducationCollege of Materials Science and EngineeringGuangxi University

Optical and micro-infrared microscope were used to observe the internal structure and mineral composition of high and low quality Chinese seawater and freshwater cultured *** clearly reveal that aragonite and calcite are found in seawater cultured pearls,but vaterite is not *** contrast,vaterite and aragonite are found in freshwater cultured pearls,but calcite is not *** on our analysis and observations of the internal structure of high and low quality cultured pearls,a modified integrated model of the internal structure of Chinese cultured pearls was *** revisions to the previous model focus on significant differences within the prismatic layer of Chinese cultured pearls.

关键词： cultured pearls aragonite vaterite calcite integrated model

Microstructure and Phase Stability of Plasma Sprayed Sc_2O_3-Y_2O_3-ZrO_2 TBCs

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稀有金属材料与工程 2011年第S4期40卷 151-154页

作者： Li Q L1,Liu H F1,2,Yang W H1,Li S Q1,Chen H J1,31National key laboratory of science and technology on Power Beam Processes,Beijing Aeronautical Manufacturing technology Research Institute,Beijing 100024,china 2state key laboratory of Powder Metallurgy,Central South university,Changsha 410083,china 3state key laboratory of advanced technology for materials synthesis and processing,wuhan university of technology,wuhan 430063, china. Beijing Aeronaut Mfg Technol Res Inst Natl Key Lab Sci & Technol Power Beam Proc Beijing 100024 Peoples R China Cent S Univ State Key Lab Powder Met Changsha 410083 Peoples R China wuhan Univ Technol State Key Lab Adv Technol Mat Synth & Proc Wuhan 430063 Peoples R China

Scandia,yttria-stabilized zirconia (Sc2O3-Y2O3-ZrO2) powder for plasma spraying was synthesized by chemical co-precipitation *** morphology and phase stability of plasma sprayed 6.8mol%Sc2O3-1.2mol%Y2O3-ZrO2 thermal barrier coatings (TBCs) were *** of the coatings were heated at 1400℃ for 500 hours and then examined by X-ray *** was found that the Sc2O3-Y2O3-ZrO2 coatings showed excellent phase stability to retain single tetragonal t' phase structure and did not undergo a tetragonal-to-monoclinic phase transition upon cooling.

关键词： thermal barrier coatings Scandia yttria-stabilized zirconia microstructure phase stability

Relationship between Ballistic Coefficient and Static Mechanical Properties for Armor materials

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Journal of university of science and technology Beijing 2001年第1期8卷 53-54页

作者： Junpin Lin, Yong Zhang, Zhi Lin, Guoliang Chen The state key laboratory for advanced Metal materials, university of science and technology Beijing, Beijing 100083, china state key Lab. advanced Metal Mat. Univ. of Sci. and Technology Beijing Beijing 100083 China

The relationship between the ballistic coefficient and the static mechanical properties of armor materials was studied. The results show that the ballistic coefficient is determined by the strength, hardness and the toughness of materials. According to the Martel rule, the equation of the relationship between ballistic coefficient and static mechanical properties satisfies the following formula: W-s=M(1+NK1C/rho )Hr. From the mixture law of composite, the prerequisite, for which ballistic coefficient has maximum to reinforcement volume fraction, is obtained by the following equation: dWs/Df=b(K(1)rho (0)-K(0)rho (1))H/rho (2)+(a+bK/rho)(H-1-H-0).

关键词： armor materials ballistic coefficient toughness