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Pressureless sintering of La-Y-sialon ceramics and grain growth in later period of sintering

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中国有色金属学会会刊：英文版 2001年第4期11卷 559-562页

作者：王零森张正富樊毅尹邦跃 Cent S Univ State Key Lab Powder Met Changsha 410083 Peoples R China

The pressureless sintering process of sialon ceramics added ( 1.5% La 2O 3+ 4.5% Y 2O 3) as sintering aids was studied. It is found that a β′ sialon with relative density over 99% is obtained by sintering at 1?750?℃ for 1?h. Crystal grain growth was observed at room temperature by SEM for the samples sintered at 1?800?℃ holding for different time. It is proved that grain growth along c axis of β′ phase is a first priority, since (210) and (001) lattice plans have different activation energy. On the present conditions, logarithm of grain aspect ratio / of average grain length to average width is in proportion to sintering time because of proportion of lg to sintering time and proportion of to sintering time.

关键词： sialon grain growth pressureless sintering

Thermodynamic study and syntheses of β-sialon ceramics

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Science China(Technological Sciences) 2009年第11期52卷 3122-3127页

作者： DONG PengLi WANG XiDong ZHANG Mei GUO Min LI WenChao Department of Physical Chemistry University of Science and Technology BeijingBeijing 100083China Chinese Society for Metals Beijing 100711China College of Engineering Peking UniversityBeijing 100871China

Based on the thermodynamic study of β-sialon and one section of Si-Al-O-N phase diagram for Si/Al=9 at 1773 K, the pure β-sialon (Si6-ZAlZOZN8-Z) ceramics with different Z values (viz. 1.4, 1.8, 2.2, 2.6, 3.0) were synthesized at different temperatures using the pressure-less technique. The relationship of the experimental-saturated Z value (the maximum Z value at a constant temperature) with temperature was then discussed. The experimental results indicated that there is a good linear relationship between Z value and temperature, which is Z=_10.76+0.0071T (R=0.9985). The β-sialon stability regions at different temperatures were exhibited in a sketch phase diagram of Si3N4-SiO2-Al2O3-AlN system. In addi- tion, the relationship between experimental-saturated Z value and the lattice parameters was also characterized, and the linear regression results a=7.604+0.02872Z and c=2.908+0.02496Z were obtained, respectively.

关键词： sialon thermodynamics synthesis oxynitride

Reaction mechanism for in-situ β-sialon formation in Fe3Si–Si3N4–Al2O3 composites

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International Journal of Minerals,Metallurgy and Materials 2017年第3期24卷 324-331页

作者： Hai-xia Qin Yong Li Li-xiong Bai Meng-long Long Wen-dong Xue Jun-hong Chen School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

In this work,Fe_3Si–Si_3N_4–Al_2O_3 composites were prepared at 1300°C in an N_2 atmosphere using fused corundum and tabular alumina particles,Al_2O_3 fine powder,and ferrosilicon nitride(Fe_3Si–Si_3N_4) as raw materials and thermosetting phenolic resin as a *** effect of ferrosilicon nitride with different concentrations(0wt%,5wt%,10wt%,15wt%,20wt%,and 25wt%) on the properties of Fe_3Si–Si_3N_4–Al_2O_3 composites was *** results show that the apparent porosity varies between 10.3% and 17.3%,the bulk density varies from 2.94 g/cm^3 and 3.30 g/cm^3,and the cold crushing strength ranges from 67 MPa to 93 *** the experimental conditions,ferrosilicon nitride,whose content decreases substantially,is unstable;part of the ferrosilicon nitride is converted into Fe_2C,whereas the remainder is retained,eventually forming the ferrosilicon *** assessment of the Si_5AlON_7 indicated that the ferrosilicon alloy accelerated the reactions between Si_3N_4 and α-Al_2O_3 fine powder and that Si in the ferrosilicon alloy was nitrided directly,forming β-Si Al ON *** addition,fused corundum did not react directly with Si_3N_4 because of its low reactivity.

关键词： alumina ferrosilicon nitride sialon liquid sintering reaction mechanisins

Preparation,structure and mechanical properties of sialon ceramics by transition metal-catalyzed nitriding reaction

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Rare Metals 2020年第5期39卷 589-596页

作者： Qing-Ming Xiong Zhi Chen Jun-Tong Huang Meng Zhang Hui Song Xi-Feng Hou Xi-Bao Li Zhi-Jun Feng School of Materials Science and Engineering Nanchang Hangkong UniversityNanchang 330063China Tianjin Boya Dadi New Material Technology Ltd. Tianjin 300382China

sialon ceramics were prepared by the nitridation of Si,Al and Al2O3 powders with the transition metals(Fe Co,Ni)*** phase composition,microstructure and mechanical properties of specimens were studied Compared with the catalyst-free specimen,the addition of Fe,Co and Ni greatly promoted the nitridation process of sialon ceramics and improved the weight gain rate and mechanical properties of *** the increased content of catalysts,the apparent porosity of the products decreased first and then increased,contrary to flexural strength and compressive *** specimen with 2.5 wt%Fe had the highest flexural strength 145.8 MPa and it exhibited the highest compressive strength of 594.6 MPa when Co content was 2.5 wt%,whereas they were 71.9 and 78.7 MPa,respectively,when without catalyst.

关键词： Transition metal sialon Whiskers or fibers Nitridation reaction Flexural strength Compression resistance

Load-dependent indentation behavior ofβ-sialon andα-silicon carbide

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Journal of Advanced Ceramics 2013年第2期2卷 185-192页

作者： Prasenjit BARICK Dulal Chandra JANA Bhaskar Prasad SAHA Centre for Non-Oxide Ceramics International Advanced Research Centre for Powder Metallurgy and New MaterialsPO:BalapurRCI RoadHyderabad 500005Andhra PradeshIndia

A comparative study was carried out on the load-dependent indentation behavior with respect to hardness and induced cracks ofβ-sialon andα-silicon carbide *** is observed that silicon carbide(SiC)exhibits lower transition load,early cracking and severely crushed indentation sites,whereasβ-sialon shows higher transition load and damage-free indentation zone even at the maximum applied load(294.19 N).Crack density is higher forα-SiC with comparison toβ-sialon at each *** exhibits both main and secondary radial types of cracking from low indentation load(0.98 N).Cracks are often associated with branching at higher load(>9.80 N)forα-SiC.β-sialon exhibits cracks which are mainly radial types initiated at 4.90 N *** opposing behaviors ofβ-sialon andα-SiC are attributed to their difference in hardness,toughness,and brittleness *** brittleness ofα-SiC results in early and severe cracking around its indentations.β-sialon shows less cracking due to its lower brittleness and higher *** increased size of indentation-induced cracks ofα-SiC is higher than that ofβ-sialon due to the rapid crack propagation inα-SiC with transgranular fracture behavior.

关键词： sialon silicon carbide(SiC) indentation hardness crack

Assessment and Prediction of Thermodynamic Functions of Compounds in sialon System

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Rare Metals 1999年第1期18卷 2-6页

作者：甄强王福明李文超 Beijing Univ Sci & Technol Dept Phys Chem Beijing 100083 Peoples R China

According to the quasi paraboloid rule, a computer program was developed and the Gibbs free energy functions of some compounds in sialon system were assessed and predicted. It makes the theoretical design of the Sial... 详细信息

关键词： sialon Standard Gibbs free energy function Quasi paraboloid rule

The effect of laser surface texturing on the tribological performance of different sialon ceramic phases

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Progress in Natural Science:Materials International 2016年第4期26卷 415-421页

作者： Bhupendra Joshi Khagendra Tripathi Gobinda Gyawali Soo Wohn Lee Research Center for Eco Multifunctional Nano Materials Sun Moon University

A tribological performance was carried out on different types of hot press sialon ceramics regarding the phases, i.e., the α-sialon phase, the β-sialon phase, and the α/β-sialon composite phase. The different phases of sialon ceramics were analyzed by XRD patterns. For the tribological performance, the sialon ceramics were laser textured and the starved lubrication method was applied with different dimple pitches under a load of 10 N at room temperature. The material having a dimple pitch of 200 mm shows the lowest coefficient of friction. The α/β-sialon composite phase shows the least coefficient of friction i.e. 0.04 and 0.1 for the textured and polished(without being textured) samples, respectively. The sialon ceramics show mild wear and therefore, the wear rate of the steel ball(mating partner) was taken into account for the wear analysis. The α-sialon phase having a higher hardness shows the least wear in comparison to the α/β-sialon composite phase and the β-sialon phase.

关键词： sialon Hot press Laser surface texturing Coefficient of friction Wear

Preparation of sialon Powder from Coal Gasification Slag

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Journal of Wuhan University of Technology(Materials Science) 2010年第6期25卷 1044-1046页

作者：汤云 State Key Lab of Western Architecture & Technology(Cultivating Base) Xi'an University of Architecture & Technology

X-ray fluorescence spectrometry（XRF）,X-ray powder diffractometry（XRD） and scanning electron microscopy（SEM） were used to characterize the chemical composition,phase constituent and microstructure of the coal gasification *** powders were synthesized by carbothermal reduction and nitridation using the coal gasification slag as raw *** experimental results showed that glass and amorphous carbon were the main phases,quartz and calcite as minor crystalline phases were also presented in porous coal gasification *** constituents of coal gasification slag were SiO2,Al2O3,CaO and residual *** powder with Ca-α-sialon as main crystalline phase can be synthesized when coal gasification slag powders were reduced and nitrided at 1500 ℃ for 9 h using nitrogen flow of 500 ml/*** coal gasification slag is a valuable and economic starting material for preparing sialon powders.

关键词： coal gasification slag characterization microstructure sialon carbothermal reduction and nitridation

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sialon复相陶瓷刀具材料的研制

无机材料学报 1996年第2期11卷 275-280页

作者：董良金黄莉萍陈菊芳孙兴伟符锡仁中国科学院上海硅酸盐研究所

本文在相关系研究与组份设计的基础上，研制成β－Ｓｉ３Ｎ４／α－Ｓｉａｌｏｎ与α＇－β＇－Ｓｉａｌｏｎ两种复相陶瓷，对这两种材料进行了力学与热学等性能以及力学性能与显微结构关系研究．并以国产原料与德国ＳｔａｒｃｈＬＣ—... 详细信息

本文在相关系研究与组份设计的基础上，研制成β－Ｓｉ３Ｎ４／α－Ｓｉａｌｏｎ与α＇－β＇－Ｓｉａｌｏｎ两种复相陶瓷，对这两种材料进行了力学与热学等性能以及力学性能与显微结构关系研究．并以国产原料与德国ＳｔａｒｃｈＬＣ—１２原料，采用ＧＰＳ与ＨＰ烧成工艺制成刀片，作了金属切削加工对比试验．研究结果表明，国产原料与进口原料差异无几．ＨＰ制成刀片耐磨性略优于ＧＰＳ，但批量生产成本高于ＧＰＳ．

关键词： sialon 复相陶瓷力学性能显微结构刀具材料