The oxidation of two ternary Ni-Cu-10 at.% Al alloys in 1 atm of pure O2 at 800-900 °C

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.     

Cast bulk ZrTiAlCuNi amorphous alloys

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.     

中高频小功率电子元器件用非晶材料的开发与应用

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。     

人工神经网络在单晶合金设计中的应用

把一种新发展的功能极强的信息处理技术－计算机人工神经网络技术用于单晶合金的高温持久性能预测并和其它方法进行比较，结果表明：这种方法精度最高。     

共混合金力学性能的研究 Ⅲ.CPP对PVC共混体系力学性能的影响

将ＰＰ氯化后作为ＰＶＣ共混体系的刚性体分散相，旨在改善高分子合金的相容性，ＤＳＣ实验表明，ＣＰＰ（氯化聚丙烯）与ＰＶＣ的相容性比ＰＶＣ与ＰＰ的好。在用弹性体增韧的ＰＶＣ／ＣＰＥ和ＰＶＣ／ＡＢＳ共混体系中加入刚性体ＣＰＰ后，随着ＣＰＥ、ＡＢＳ用量的增加，共混合金的冲击强度增加，并且由刚性的ＣＰＰ的加入所产生的冲击强度最大值的幅度也有所提高，其趋势是ＣＰＥ、ＡＢＳ用量越多，共混合金冲击强度值达到最大值时所需ＣＰＰ的量越多，增加的幅度也越大。ＣＰＰ对共混合金的拉伸屈服强度和断裂伸长率的影响比较小。     

Comparison of supports for the direct synthesis of hydrogen peroxide from H2 and O2 using Au–Pd catalysts

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.     

Strengths and ductility of Mo–TiC alloys after secondary recrystallization

A series of Mo–TiC alloys were heated in vacuum at 2473 K for 36 ks. First grain growth behavior was observed using a scanning electron microscope. Then effects of TiC addition on the strengths and ductility at low temperature were discussed from the viewpoints of chemical composition and grain structure.

Materials with TiC additions of not larger than 0.1% demonstrated a single-crystalline grain structure. Both yield and maximum strengths increased by TiC addition and consequently ductility was improved.     

富Ag的Ag—Cu合金再结晶

用度测量、示差扫描量热（ＤＳＣ）、金相显微镜、透射电镜等技术研究了富Ａｇ的Ａｇ－Ｃｕ合金的再结晶。对合金再结晶温室随Ｃｕ含量的变化规律以及在相同变形量下，Ｃｕ含量对合金再结晶过程中冷加工储存能的释放的影响进行探索，并讨论了结果。     

介绍一种生产冲挤用铝合金坯料的新工艺

哈兹列特铝板带连铸连轧工艺已被成功地用于铝和铝合金冲击挤压用坯料的生产。在对哈氏四个有关用户扫描的基础上，列举了其产品及其用途，并介绍了相关工艺及其优点。     

Ti-Mo合金的氢化物热解析动力学研究

本文对不同钼含量的钛钼合金Ti(1-x)Mox(x=3,11,20,33,50,at%)氢化物的热解析动力学进行了研究, 在高真空金属系统中测试了合金氢化物热解析量随时间的变化关系,应用反应速率分析方法计算了解析速率常数和表观活化能.研究结果发现,氢化物的热解析过程可用一级反应速率方程来描述,而氢原子在合金体相中的扩散是热解析过程的控速步骤.热解析表观活化能随Mo含量的增加而减小,说明氢化物的热稳定性随Mo含量的增加而降低.