Yanbao Zhao Guofang Li Zhijun Zhang
材料科学技术（英）
BiIn/In2O3 composite dendritic nanocrystals were prepared by dispersing alloy droplets in paraffin oil. The morphology and structure of the alloy nanocrystals were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), and X-ray powder diffraction (XRD). The composite nanocrystals have dendritic morphology, with an average diameter of 10 nm and lengths up to tens and even hundreds of nanometers. Tribological results indicate that the composite nanocrystals as oil additives can improve antiwear ability of base oil, which is better than that of the corresponding monometallic particles. In addition, the lubricating mechanism of the composite nanocrystals was also discussed.
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Alloys
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null
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null
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O.B.Perevalova
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E.V.Konovalova
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N.A.Koneva
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E.V.Kozlov
材料科学技术（英）
The study of the triple junctions of the grain boundaries in some fcc solid solutions, ordered alloys and intermetallics with L12 has been carried out using the optical metallography and TEM methods. Two-types of the triple junctions were found in the alloys investigated (1), consisting of the boundaries of the random (RT), and (2), consisting of the RT boundary and the special boundaries (ST). The relative values of the RT and ST boundary energy were determined on the basis of the measurements of the angles between the grain boundary planes. It has been shown that the energy of ST boundaries increases with the increase of the stacking fault (SF) energy. The energy of the RT boundaries does not depend on the SF energy.
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Alloys
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null
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null
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S. Ahmad
材料科学技术（英）
The structure and thermal parameters of Ni20Pd80 alloy were studied by X-ray diffraction(XRD). The diffraction experiments performed in the temperature range of 308-1100 K revealed that the alloy formed a face centered cubic (fcc) A1-type structure. The temperature dependence of the lattice parameters was investigated by using the Bragg line displacement method showing that the lattice parameter increases with the increase of temperature. The mean linear thermal expansion (MLTE(%)), coe±cient of thermal expansion (CTE, α), the characteristic Debye temperature (θD) and mean square amplitudes of vibration were determined from XRD data. The value of Debye temperature was found to be 253 K. It was found that temperature factor was independent of the static displacements.
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Alloys
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null
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null
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吴崇周
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2016.05.002
介绍国内50多年以来,发展比较成熟和使用性能稳定可靠的一些钛合金,可供设计人员选用.同镍基高温合金和不锈钢相比,钛合金的组织比较复杂,对制造工艺比较敏感,这也是在制造钛合金零部件时,必需注意的问题.本文介绍和推荐了高强钛合金TC18、TC21和T86的一些基本性能,高温钛合金则介绍和推荐了TC25、TC11、TC6、TC4、TA19和TA15合金,与国外的Ti-100、IMI834、BT18Y、BT25Y和BT36等高温钛合金相比,TC25和TA15合金综合性能较好,加工制造工艺比较简单,成本低,更适合在国内推广应用.同时也对钛合金的发展趋势作了一些说明.
关键词:
飞行器
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合金
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强度
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高温强度
