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91.
92.
V. A. Lavrenko L. A. Glebov A. P. Pomitkin V. G. Chuprina T. G. Protsenko 《Oxidation of Metals》1975,9(2):171-179
The kinetics of titanium carbide oxidation in oxygen over the temperature range of 600–1200°C and oxygen pressure from 0.1 to 740 Torr have been studied with a vacuum microbalance. Layer-by-layer x-ray analysis, petrography, metallography, and gas chromatography have been used to analyze the oxidation products. A paralinear nature of the oxidation of material was established, and the rate constants of the process were calculated for the corresponding parabolic and linear portions of the kinetic curves. It was shown that a gaseous product, CO2, formed, as well as a solid product, TiO2 (rutile), both stoichiometric and nonstoichiometric. The lower oxides, Ti3O5, Ti2O3, TiO, were noted in the scale at temperatures from 700 to 800° and low oxygen pressures, their relative quantity rising with decreasing pressure. Based on x-ray analysis and microhardness measurements, it was concluded that titanium oxicarbides formed in the TiC, directly adjacent to the scale. A possible oxidation mechanism of titanium carbide is proposed. 相似文献
93.
采用固相合成法制备出系列Fe掺杂的Bi2Sr2Co2Oy,样品,并对样品进行XRD分析,电阻率(p)、热电势(固和顺磁共振研究。结果表明:Fe掺杂浓度x≤0.3时样品基本为单相。Fe掺杂使体系的电阻率略微增大,热电势显著升高,这可能与Fe掺杂降低了空穴载流子浓度有关。Fe掺杂浓度x=0.05样品获得最大的功率因子(power factor,S^2/P)。顺磁共振结果显示,不掺Fe的样品有着较强的顺磁共振(ESR)信号,随着Fe含量的增加,ESR信号向低频方向移动,并逐渐宽化减弱直至消失。这表明Fe掺杂改变了体系的自旋关联状态,占据了Co位参与了Co—O—Co之间的自旋关联。研究结果表明合适的元素掺杂可以有效地调整体系的自旋关联状态,改善材料的热电性能。 相似文献
94.
S.V. Zherebtsov G.A. Salishchev R.M. Galeyev O.R. Valiakhmetov S.Yu. Mironov S.L. Semiatin 《Scripta materialia》2004,51(12):1147-1151
The “abc” deformation method for production of large-scale billets with submicrocrystalline structure was developed. A large billet of Ti–6Al–4V alloy (150-mm diameter × 200-mm length) with a homogeneous submicrocrystalline structure was produced. The refined structure with a grain/subgrain size of about 0.4 μm leads to a substantial mechanical properties improvement. 相似文献
95.
机械能辅助渗铝工艺及渗铝层性能研究 总被引:1,自引:0,他引:1
机械能辅助渗铝是将机械能与热能相结合一种新渗铝工艺,可以将渗铝温度降低到560~650 ℃.本文通过实验对机械能辅助渗铝工艺进行了研究,对主要工艺参数进行了优化,获得了组织致密、渗层厚度≥60 μm、以Fe2Al5相为主要组成相的渗铝层,并研究了渗铝钢的抗高温氧化性能及机械性能. 相似文献
96.
《Synthetic Metals》2006,156(18-20):1187-1193
Miscible blend of conductive polyaniline/polyurethane (PANI/PU) showed preferable electrical property at low percolation threshold compared to immiscible blend of PANI/polystyrene-isoprene-copolymer (PANI/SIS) and carbon black/PU composite (CB/PU). The time dependence of the electrical conductivity was investigated with these samples aged under different humidity and temperatures. The electrical conductivity of PANI/PU (11.5/88.5, v/v) decreased with aging time and the morphology changed with time in the coexistence of high moisture and high temperature. After the aging treatment, the film of the miscible blend was re-dissolved and re-cast. The morphology and electrical conductivity were found to recover to the same state as the original film. In addition, the recovery mechanism of the morphology and the conductivity was also proposed here. 相似文献
97.
98.
V. A. Pavlovskii 《Protection of Metals》2007,43(3):281-284
Electroplating tantalum coatings on molybdenum, copper, and steel is studied. The effects of various factors (the composition
of a fluoride bath, its temperature, current density, and the electric charge spent) on the electrocrystallization of the
deposit, its roughness, the degree of dendrite formation, current efficiency, and a possibility to plate multilayer coatings
and produce tantalum wares by electrotyping are investigated. To compare the characteristics of the coatings, the studies
in a standard chloride-fluoride salt system containing potassium fluorotantalate (K2TaF7) were also carried out under similar conditions.
Original Russian Text ? V.A. Pavlovskii, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 303–306. 相似文献
99.
100.