惰性气体熔融-红外/热导法测定二硼化钛增强铝基复合材料粉中氧、氮

建立惰性气体熔融-红外/热导法测定增材制造用TiB_2增强铝基复合材料粉中氧和氮含量的分析方法。采用单因素法,对仪器功率、助熔剂种类和称样量等实验条件进行优化选择。以镍箔-镍篮为空白样品,以11次空白样品测定结果标准偏差的3倍作为检出限,计算得氧、氮检出限分别为0.000 8%、0.001 0%。实际样品测定结果的相对标准偏差均小于5%(n=7),氧、氮的加标回收率为95.8%~106.6%。该方法操作过程简单,满足TiB_2增强铝基复合材料粉中氧、氮元素含量的测定要求。

甲基丙烯酰氧丙基三甲氧基硅烷-醋酸乙烯酯共聚物/二氧化硅杂化材料的制备和性能研究

通过溶胶凝胶法制备了甲基丙烯酰氧丙基三甲氧基硅烷醋酸乙烯酯/二氧化硅杂化聚合物材料;用紫外光谱(UV),傅立叶红外光谱(FT-IR)对聚合物进行了结构表征;溶胶抽提结果表明杂化材料体系中凝胶的含量很高;SEM观察了杂化材料的形貌;示差扫描量热法(DSC)、热重法(TG)测试分析了材料的热稳定性。

硅中的氮氧复合物及其施主行为

含氮 CZ硅的电学性能完全有别于含氮的 FZ硅和无氮的 CZ硅 .研究表明 ,含氮 CZ硅能形成一种与氮有关的新施主 ,它随氮氧复合物的形成而形成 ,随氮氧复合物的消失而消失 .文章进一步研究了氮 -新施主的形成和消除与热处理条件的关系 。

Si-Al-O-N系中的新型耐火材料

介绍了Si Al O N系中的新型耐火材料 :Alon结合Al2 O3,Sialon结合Al2 O3,A3S2 -Sialon结合Al2 O3,O’ Sialon结合Al2 O3 及O’ Sialon -ZrO2耐火材料的特点、性能和制备工艺过程 。

聚合物自由基锂二次电池正极材料的合成与电化学性能

合成了一种聚合物自由基聚 4 甲基丙烯酸 2 ,2 ,6 ,6 四甲基哌啶 1 氮氧自由基酯 (PTMA) ,并用红外光谱 (IR)、紫外光谱 (UV)、电子顺磁共振 (ESR)等证实了PTMA的结构 .PTMA的循环伏安曲线 (扫描速度为 5mV·s- 1)显示通过阳极的氧化电量和阴极的还原电量相等且氧化峰电流等于还原峰电流 ,表明PTMA的氧化还原反应可逆性很好 .PTMA的氧化峰电位 (Ea ,p=3 6 6VversusLi Li+ )与还原峰电位 (Ec,p=3 58V)之差为 80mV ,比其它锂二次电池的有机正极材料 (如有机二硫化物 )小得多 ,因此PTMA的氧化还原反应速度比较快 .PTMA的最大放电比容量为 78 4mAh·g- 1(以 0 2C充放电 ) ,是它理论比容量 ( 111mAh·g- 1)的 70 6 % ,它的充放电曲线分别在 3 6 5V和 3 56V处有一个很平稳的平台 ,经过 10 0次充放电循环后电池的放电比容量相对于最大放电比容量只衰减了 2 % ,表明PTMA 锂扣式电池具有优良的循环稳定性 .

高炉软熔带渣对原位TiN/O′-sialon材料侵蚀的研究

采用静态熔滴法研究了模拟高炉软熔带渣对原位TiN/O′sialon材料的侵蚀机制。利用高温X射线透视装置观察炉渣的熔化和与材料的相互作用过程。XRD分析残渣中的物相 ,EPM分析材料被侵蚀部位的显微结构和元素分布。结果表明 :熔渣对材料的侵蚀主要是熔渣渗透并与材料发生化学反应。材料被侵蚀后结构发生变化 ,可大致分为渣带、渗透带和未变带。熔渣与材料相互作用生成的新的高熔点相以及熔入的TiN使熔渣的粘度增大、流动性降低 ,进而阻止熔渣的进一步侵入。材料中TiN含量的增加将提高材料的抗渣侵蚀能力。

纳米SiO_2/有机硅/聚丙烯酸酯复合乳液的合成

以含有共聚基团的有机硅化合物改性纳米 Si O2 ,通过与丙烯酸酯单体共聚 ,合成了一系列纳米 Si O2 /有机硅氧烷 /聚丙烯酸酯复合乳液 ,其硅质量分数可以在 5 %～ 70 %之间连续变化 ,研究了反应时间、单体配比。

Thermodynamic Investigation of Synthesizaing Metastable β—Sialon—Alon Composite Ceramic

Based on its thermodynamic analysis ,β-Sialon-Alon metastable composite ceramic has been prepared by hot pressing sintering,XRD results indicate that the product of hot pressing singering is indeed Sialon-Alon metastable omposite ceramic ,which is in accordance with thermodynamic

微量Al掺杂对2D C/SiC性能的影响

以二维编织碳纤维碳布为预制体,采用聚铝碳硅烷(PACS)为聚合物前驱体,应用化学气相渗透(CVI)结合聚合物浸渗-裂解(PIP)工艺制备微量Al掺杂2D C/SiC复合材料。研究微量Al掺杂对C/SiC微观结构、力学、热膨胀和氧-乙炔焰烧蚀性能的影响。结果表明:掺杂微量Al未改变C/SiC的微观结构和热膨胀性能,也未降低其韧性和强度;但微量Al掺杂提高了C/SiC的抗烧蚀性能,含微量Al的SiC氧化形成微量Al熔于SiO2的固熔体,微量Al提高了SiO2的黏度和致密度,减小SiO2挥发,较未掺杂Al的C/SiC相比,线烧蚀率降低了26%。

Reaction Mechanism of O‘—sialon—ZrO2 Composite by Using Reaction Nitridation Mathod

O'-sialon-ZrO2 composite based on the cheap commercial available zircon and silicon as raw materials can be achieved by using reac-tion nitridation method,More attention was given to the nitriding process and the effect of additives on it .The experimental results show that there are two nitridation paths:one is the direct nitridation of silicon powder and the other is through the reaction between the medi-um compound ZrSi2 and the nitrogen.The effects of addition of calcia and the incorpora-tion of BN on the nitriding reaction were also investigated,the primitive experimental results demonstrated that both of calcia and BN could deteriorate the nitriding degree.

Fractal Calculation of Mo／β‘—Sialon Functionally Gradient Materials by Powder Metalurgy

The preparation of disk shaped Mo/β'-sialon functionally gradient material(FGM) is studied.Random fractal of diffusion interface in Mo/β'－sialon FGM is also studied by variation method.

Improvement of FeO Corrosion Resistance by Addition of β－Sialion in Matrix of Corundum Castable

Silicon aluminum oxynitride (β-Si4Al2O2N6) powder was added into corundum castable and its FeO corrosion resistance was tested in crucible method.It was found that FeO corrosion resistance of sialon containing corundum castables was better than that of no sialon powder added ,The optimum content of the sialon powder in castables was higher than mass of the sialon powder in castables was higher than mass 15%.Moreover,O'-sialon phase,together with β-sialon phase occurred in corundum castables heated in coke bed at 1500℃,although β-sialon powder was initially admixed into the matrix of castables.The EPMA results showed these nitrogen-containing phases located in the matrix of castables were favorable to hinder the penetration of FeO melt at high temperature in comparison with pure corundum castable.However,the flowability of corundum castable became worse originated from the sialon powder added.

Slag Corrosion Resistace of β－Sialon－Al2O3 Composites－Part I. Thermodynamics and Mechanism

Slag corrosion resistance of β－Sialon and β－Sialon-Al2O3 composites has been studied .The effects of FeO content and temperature on corrosion rate have been investi-gated by mens of dip method(static and self-rotating).The corrosion process and microstructural analysis.It is shown that FeO preferentially attacks β-Sialon in the composite and the protruded corundum grains would gradualy fall off into the slag.

Investigation on Reaction Synthesis of Sialon Multiphase Refractory from Clay and Additive TiO2

Sialon multiphase composites containting titanium-carbon or titanium-nitrogen have been synthesized from clay nd additive titania through different sintering processes,The experimental results indicated that there was a great change of crystal phase in the similar-composition specimens singtering in air ,nitrogen and bedding protecive poder respectively,determined by XRD analysis,The subsequent evidences were also supplied by SEM.The improvement in mehanical properties of multiphase refracto-ries was observed as the amount of titania changing from 0 to 16%,The main causes maybe come from the excellent properties of high hardness and in-situ strengthening effects of the in-situ formed secondary phase,TiC or TiN.

Development of Sialon Bonded Corundum Bricks

Influence of additives and composition of the matrix on mecharical properties of Sialon bonded corundum brick with appropriate nitridation sintering curve was investigated in present paper.The phase composition and microstructure of the sintered specimen were analyzed by means of SEM and XRD.The results indicate that with appropriate content of ultra-fine alumina powder and aditive A,both cold and hot mechanical properties of speimens are notably enhanced.The microstructure of specimen is dense and with less porosity,Main phase of the specimen is corundum, β－sialon is also observed as the bonding phase, little impurity is observed.

Analysis and Prediction of Sintering Behavior of Diphase Sialon and Diphase β—Sialon／Alumina Composites by Artificial Neural Network

In this paper,the sintering behavior of diphase β-Sialon and Al2O3/diphase β-Sialon composites has been studied and predicted by using ANN (Artificial Neural Network) method.It is found that relative density is well correlated with phase composition and sintering temperature and that the predicted values by this method are very clos to experimental results.Effectiveness of modeling has been discussed nd analyzed by presenting formulas, This may be the first attempt of applying ANN mthod in the study of refractories science and has indicated that ANN is an efficeint method.

Synthesis of β‘—SIALON Powder from Clay

The synthesis of β'-sialon powder by carbothermic reduction of clay followed by nitridation has been carried out.The effect of charge mixture,temperature,holding time and nitrogen flow rate on synthesis was examined.The fired sample was identified by XRD and the nitrogen content of fired sample was measured.The synthesis process of sialon powder was described.

Study on the Microstructure of β‘—Sialon／SiC（w） Composites

The phase composition and microstructure of β'-Sialon/SiC whisker compostie materials were studied by means of XRD ,SEM,EDAX and HREM.Besides β'-Sialon and β-SiC as main crys-talline phases,15R AIN polytypoids presented in the materials,Yttrium,added in Y2O3 as sintering aid,was concetrated mainly in glassy phase,A mosaic structure of SiC whisker in β'-Sialon grains was observed,Two kinds of grain boundaries were also observed:one was a direct-contact grain boundry between β'-Sialon and β-SiC,while the other was a boundary between β'-Sialon grains wqith glassy phases.

Slag Corrosion Resistance of β－Sialon－Al2O3 Composites－Part Ⅱ.Kinetics

The kinetic process of slag corrosion for β－Sialon and β-Sialon-Al2O3 composites has been studied by means of dip method (static and self-rotating),The corrosion model is buitl and the formula of corrosion rate is deduced,which are in accordance with experimental results.