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81.
R. C. Pennefather D. H. Boone 《International Journal of Pressure Vessels and Piping》1996,66(1-3):351-358
Cyclic oxidation tests were performed on a large variety of commercially available overlay coatings. The results of cyclic oxidation tests confirmed that the composition of the coating as well as the processing method of the coating can affect the life of the system. Coating life was determined by the time to coating penetration and initiation of substrate attack. As this work was part of a effort to evaluate the relative protectiveness of available coating systems for Industrial Gas Turbine applications at relatively high temperature, an extensive testing programme was undertaken. The different coatings were tested to visual failure. The results presented in this paper concentrate on the surface instability of the coating. Apart from usual oxidation of the coating an additional degradation mechanism was observed. A mechanical effect caused by the instability of the coating as a result of the difference in the thermal coefficient of expansion and mechanical properties between the substrate and coating. This effect, the so-called “rumpling” effect, resulted in a significant reduction in time to penetration and was in some systems the life controlling factor. 相似文献
82.
K Umakantham K Chandramouli G Nageswara Rao A Bhanumathi 《Bulletin of Materials Science》1996,19(2):345-355
Rare-earth doped strontium barium niobates were synthesized using usual ceramic technique. The dopants are La, Ce, Gd, Sm
and Nd. The materials were characterized by XRD and density measurements. The grain sizes were determined from SEM analysis.
Lattice parameters changed uniformly with rare-earth dopants in unfilled structures. Density measurements and SEM analysis
confirmed only minute changes in the densities of the ceramics. 相似文献
83.
We analyze specific features of the design of equipment used for mechanical testing of sheet structural materials under the conditions of biaxial static, cyclic, or dynamic loading. We propose original solutions of the problems related to the fatigue testing of crosslike specimens performed without using complex hydraulic systems and their dynamic testing carried out by using very simple testing machines for uniaxial tension–compression. 相似文献
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85.
The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces,and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were inverstigated.The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed.Experimental results show that the concentration,the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption.Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption. 相似文献
86.
液相添加剂对PTCR陶瓷电性能的影响 总被引:3,自引:2,他引:1
液相添加剂AST(Al2O3+SiO2+TiO2)对BaTiO3陶瓷材料电性能的影响很大,随着Al2O3含量的增加,材料的电性能降低;SiO2、TiO2的物理特性对材料电性能影响较大;过量TiO2对材料PTC效应有重要影响,适当过量TiO2含量,可得到性能优良的PTCR陶瓷。 相似文献
87.
氮化硅的性能及其聚合物材料 总被引:1,自引:0,他引:1
陈继兰 《高分子材料科学与工程》1996,12(6):144-147
叙述了氮化硅(Si3N4)的性能并制备了含Si3N4的聚合物材料,这种材料在医学上具有重要价值,对改变医学方面的概念、和对促进人类健康长寿具有重要意义。 相似文献
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