Protective coatings for carbon bonded carbon fibre composites

Carbon bonded carbon fibre composites (CBCF) were modified by direct reaction with molten silicon in order to obtain a silicon carbide layer on the composite surface. Subsequently, the Si-infiltrated CBCF material was coated with a silica-based glass containing yttria and alumina by means of a slurry-dipping technique. On heat treatment the glass yielded a glass-ceramic layer thus giving a multi-layered oxidation and erosion protection system. The microstructural characterisation of the coating was conducted by standard microscopy techniques and by X-ray diffraction. The controlled crystallization of the glass-produced cristobalite, yttrium silicate (Y₂Si₂O₇, keiviite, β-form) and mullite as main crystalline phases. These are excellent ceramic materials for oxidation and erosion protection of SiC-coated carbon-based composites since their coefficients of thermal expansion (CTE) closely match that of SiC. The possibility of healing (closure) of micro cracks by a thermal treatment at 1375 °C, thus exploiting the viscous flow of the residual glass in the glass-ceramic, was explored in order to extend the service life of the protection system.     

Dielectric relaxation of monoesters based poly(styrene-co-maleic anhydride) copolymer

A series of alkyl-grafted copolymers based on styrene-maleic anhydride (SMA) copolymers were synthesized by esterification of SMA with several long chain normal aliphatic alcohols. The prepared copolymers were characterized by FT-IR and ¹H NMR and DSC. The dielectric behavior of these copolymers was investigated in the frequency 20–10⁵ Hz and temperature −40 to 180 °C ranges. Two relaxation processes were observed, α, and β-relaxation. The former is associated with the glass-rubber transition and is characterized by the Vogel–Fulcher–Tammann temperature dependence and the latter relaxation is related to the local motion of the ester side groups attached to the polymer backbone. The apparent activation energy for the β-relaxation was found to depend significantly on the alkyl chain length. The dielectric analysis of the β-relaxation process detected is discussed.     

离子交换增强玻璃的EPMA研究

应用电子探针研究了两种钠钙硅玻璃经低温离子交换后表面层中 K~ 离子的浓度分布与交换条件的关系。结果表明:在离子交换过程中,K~ 与 Na~ 是一对一交换的;交换层厚度和交换总量都与时间的平方根成正比,与绝过温度间有指数关系。运用 Fick 定律对结果进行了讨论。     

MgF_2镀膜对 ZrF_4-BaF_2-AlF_3-YF_3系统玻璃耐侯性的影响

本文采用红外透射光谱、红外反射光谱、扫描电子显微镜、X 射线能量色散谱仪等方法研究了表面蒸镀 MgF_2镀膜对 ZBAY 系统玻璃耐风化性能的影响,并对该玻璃试样风化侵蚀机理和水化侵蚀机理进行了比较。实验结果表明:ZBAY 系统玻璃的风化侵蚀机理和水化侵蚀机理并不完全相同。ZBAY系统玻璃在较强的风化条件下和较强的水化条件下发生严重的侵蚀。而 MgF_2镀膜能够有效地改善ZBAY 系统玻璃的耐风化和耐水侵蚀性能。     

镁基大块金属玻璃的研究进展

从发展过程、制备、性能、复合材料等几个方面，对镁基大块金属玻璃的研究进展进行了回顾，并对镁基大块金属玻璃研究中遇到的问题和镁基大块金属玻璃的发展前景进行了探讨，认为在重视开发新型镁基大块金属玻璃的同时，必须不断探索镁基大块金属玻璃制品的开发和商业应用。     

Estimating creep deformation of glass-fiber-reinforced polycarbonate

Thermoplastic resin and fiber-reinforced thermo-plastics (FRTPs) were used without post-cure treatment as “molded material.” For such materials, creep behavior and physical aging occur simultaneously. This study examined the creep behavior of polycarbonate (PC) and glass-fiber-reinforced polycarbonate (GFRPC) injection moldings, including the effect of physical aging and fiber content, and determined that the time–temperature superposition principle could be applied to the creep behavior for different fiber contents. The effects of physical aging on creep behavior were evaluated quantitatively on pure resin and with various fiber contents without heat treatment. We found that the effect of physical aging could be evaluated with the proposed factor, “aging shift rate.” To discuss the linearity of viscoelasticity in FRTPs, this study used two shift factors: time and modulus shift factors. The fiber content affected creep behavior by both retarding and restraining it through changing the elastic modulus. This was shown by generating a grand master curve of creep compliance, which included the effects of time, temperature, and fiber content. Using the grand master curve of creep compliance and shift factors, it was possible to estimate the creep deformation of molded materials under varying conditions and fiber contents. The estimated creep deformation gave a very good fit to the experimental creep deformation.     

真丝斜纹绸转移印花工艺的探讨

探讨了用三聚氰胺、多聚甲醛和聚乙二醇合成的树脂ＴＰ对真丝斜纹绸预处理和转移印花工艺及机理，真丝斜纹绸转移印花织物手感良好，耐洗色牢度达到一等品要求。     

涤棉细布酸减量仿丝绸生产工艺探讨

涤棉织物经过酸减量整理后，手感柔软滑爽，具有仿真丝效果。文章介绍了酸减量仿丝绸的生产工艺，并提出了生产中应注意的事项。     

非晶转变的两种主要理论模型

本文首先总结了非晶转变的特点，然后着重评述了关于非晶转变的两类主要理论模型及非晶转变的理论研究进展，并简要介绍了我们对非晶转变的观点。     

功能织物的研究及应用开发

以纳米粒子作为载体,通过特殊的工艺试图制造出具有抗紫外线、抗可见光、抗红外线和抗电磁波等性能的多功能织物,以求对于人类健康作出贡献。