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41.
42.
钛合金优良的耐海水腐蚀性能、高的比强度、无磁性等特点,使其在船用领域大有潜力可为,我国的船用钛合金经过近40年的研究开发,基本能满足舰艇不同强度级别的需求,在舰船上应用具有明显的社会效益和经济效益,值得进一步应用推广。本文介绍了国内外舰船用钛合金的开发及应用情况。对钛合金在鱼雷发射水缸、高压气瓶、一回路危急冷却器、声扫雷具、二回路泵、阀及管系、声纳导流罩、螺旋桨等方面的应用作了重点介绍。 相似文献
43.
44.
A Ml (NiCoMnA1)5 hydrogen storage alloys was prepared by double-roller rapid quenching.Its microstructure, electrochemically and kinetic characteristic were studied.A uniform crystal phase with CaCu5 structure could be detected by XRD analyses, whose average grain size is 30 ~ 50 nm and the ratio of c/a of nano-crystal hydrogen storage alloy is larger.The hydrogen absorption/desertion p - C isotherms of alloy show that its fiat-performance is perfect and the magnetic stagnant effect is very little.An simulate cell is used for electrochemical measurement.Electrode is 10C, the capacity decreasing rate via the 450 cycles at 7C is less than 20%. 相似文献
45.
J.H Xiang 《Corrosion Science》2004,46(8):2025-2039
The oxidation of the ternary alloys Ni-45Cu-10Al and Ni-30Cu-10Al has been studied at 800-900 °C under 1 atm O2. The presence of 10 at.% Al reduces significantly the oxidation rate of the corresponding Cu-Ni alloys during the initial oxidation stages, even before the establishment of a complete Al2O3 layer. The weight of individual sample of the two ternary Ni-Cu-10Al alloys at 800 °C increases more rapidly than at 900 °C during the initial oxidation stage. As oxidation proceeds, the weight gain at 800 °C slows down to a degree that the total weight gain after 24 h oxidation at 800 °C is less than that at 900 °C. Due to a faster formation of the Al2O3 layer, which suppresses earlier the further oxidation of Cu and Ni, the external region of the scales grown on Ni-45Cu-10Al contain much less Cu and Ni oxides than those grown on Ni-30Cu-10Al. The transition from the internal oxidation to the selective external oxidation of the most reactive component Al in Ni-Cu-Al alloys is favored by higher values of the Al content, of temperature and of the Cu/Ni ratio. 相似文献
46.
L.Q. Xing P. Ochin M. Harmelin F. Faudot J. Bigot J.P. Chevalier 《Materials Science and Engineering: A》1996,220(1-2)
Cylindrical bulk amorphous samples with diameters up to 10 mm have been prepared by casting ZrTiAlCuNi alloys in a copper mould. In order to rank glass-forming ability as a function of alloy composition, alloys were also cast into wedge-shaped moulds; to a first approximation, the thickness of the amorphous region obtained can be taken as an indication of glass-forming ability. The compositions which lead to the production of bulk glasses all have reduced glass transition temperatures in excess of 0.65 and the extremely high glass-forming ability of these compositions is discussed. We suggest that both the Al and Ti contents are determining factors for the production of bulk amorphous samples and these are believed to reduce the driving force for, and hence the rate of, crystallisation. These amorphous alloys have been found to display high thermal stability and can be annealed for several minutes in the supercooled liquid region. They are ductile at room temperature and have a high value of yield stress. 相似文献
47.
随着电力和电子技术的飞速发展,相应的元器件向高频化,小型化,高效率和节能的方向发展,从而对元器件用材料也提出了更高要求。为此,本文概述了冶金部钢铁研究总院近年来所研究的用于开关电源,脉冲变压器,传感器,电流互感器和电感器等方面的非晶软磁合金的性能及其应用概况。 相似文献
48.
Jennifer K. Edwards Adrian Thomas Benjamin E. Solsona Philip Landon Albert F. Carley Graham J. Hutchings 《Catalysis Today》2007,122(3-4):397-402
The direct synthesis of hydrogen peroxide from H2 and O2 using a range of supported Au–Pd alloy catalysts is compared for different supports using conditions previously identified as being optimal for hydrogen peroxide synthesis, i.e. low temperature (2 °C) using a water–methanol solvent mixture and short reaction time. Five supports are compared and contrasted, namely Al2O3, -Fe2O3, TiO2, SiO2 and carbon. For all catalysts the addition of Pd to the Au only catalyst increases the rate of hydrogen peroxide synthesis as well as the concentration of hydrogen peroxide formed. Of the materials evaluated, the carbon-supported Au–Pd alloy catalysts give the highest reactivity. The results show that the support can have an important influence on the synthesis of hydrogen peroxide from the direct reaction. The effect of the methanol–water solvent is studied in detail for the 2.5 wt% Au–2.5 wt% Pd/TiO2 catalyst and the ratio of methanol to water is found to have a major effect on the rate of hydrogen peroxide synthesis. The optimum mixture for this solvent system is 80 vol.% methanol with 20 vol.% water. However, the use of water alone is still effective albeit at a decreased rate. The effect of catalyst mass was therefore also investigated for the water and water–methanol solvents and the observed effect on the hydrogen peroxide productivity using water as a solvent is not considered to be due to mass transfer limitations. These results are of importance with respect to the industrial application of these Au–Pd catalysts. 相似文献
49.
镇沅金精矿选择性固砷焙烧—氰化浸出新工艺研究 总被引:6,自引:0,他引:6
对云南镇沅金矿的难当金精矿进行了选择性固砷焙烧-氰化浸出的试验研究,取得了满意结果。砷固定率大于92%,硫挥发率为78%-84%,金浸出率可达91%-93%。选择性固砷焙烧-氰化浸出新工艺可有效消除砷害,综合利用有价成分硫,特别适宜于含砷高硫,同时含碳等杂质的细粒浸染型难浸金矿石的处理,在我国有较大的发展前景。 相似文献
50.
通过对组成打结料成分特性的研究,提出以优质原料生产的MgO-CaO-Fe2O3系合成砂为骨料,用MgO〉97%,粒度〈0.088mm烧结镁砂做细粉,适当添加超微粉等工艺措施,制成适当高碳铬铁电炉炉底用的高基质打结料,通过调控基质成分,实现材料相和固相的复合烧结。 相似文献