Fe3Al/TiC复合材料的高温抗氧化性能

研究了Fe_3Al/TiC复合材料的高温抗氧化性能。结果表明:Fe_3Al/TiC复合材料在950℃的氧化动力学特征均近似服从抛物线规律,并且随TiC含量增加,Fe_3Al/TiC复合材料的高温抗氧化性能降低。     

Al2O3和Fe2O3为何不溶于盐酸

一、若干实验事实回顾初中化学讲"酸的化学性质"时,将生锈的铁钉分别放入盛有稀盐酸和稀硫酸的试管里,观察反应所发生的现象。Fe_2O_3 6HCl=2FeCl_3 3H_2OFe_2O_3 3H_2SO_4=Fe_2(SO_4)_3 3H_2O高中化学讲元素周期律和 Al_2O_3性质时,曾讲过     

言语行为理论在英语教学中的渗透和运用

在英语教学中运用言语行为理论,有助于学习者对语意的正确理解,有利于提高教学效果。     

Al和Fe的GAEAM模型

用普适分析型嵌入原子模型（GAEAM）[1]确定了Al和Fe的嵌入原于模型参数，并用得到的模型参数计算了它们的空位形成能、表面能等物理常数．结果表明。Al的RX结构是最稳定的结构。Fe的麟结构是最稳定的结构．     

试论言语行为理论在英语教学中的渗透和运用

在英语教学中运用言语行为理论,有助于学习者对语意的正确理解,有利于提高教学效果.     

Ti—Al基合金的组织和性能研究

Ti-Al基合金作为一种新型材料,拥有众多优越的性能。本文对Ti-Al基合金的组织、性能及最新的研究状况做了综合的介绍。     

凹凸棒石吸附地下水中的Fe3+研究

凹凸棒石是一种含水,富镁、富铝的硅酸盐黏土矿物,由相互平行的硅氧四面体双链组成,比表面积大,具有良好的吸附性能.通过静态实验,探讨了凹凸棒石吸附水中Fe3+时的影响因素.结果表明,在Fe3+浓度为20.00 mg/L时,使用2.00 g凹凸棒石、水浴温度为30℃、初始pH值为4至5,吸附40 min后对水中Fe3+的去除率最大.另外,研究表明,Fe3+去除率随吸附时间的增加呈曲线变化,随凹凸棒石样品的用量的增加有所增加,随pH的增加明显增加,随着温度升高影响不大.根据吸附等温线知,凹凸棒石吸附Fe3+的规律较好地满足Langmuir吸附等温式.     

Al2O3粒子在镁合金空化强化中的作用效果

通过空化泡溃灭产生的微射流促使Al2O3纳米粒子对镁合金进行冲击强化.采用显微硬度仪、扫描电镜(SEM)、X射线光电子能谱(XPS)对强化后的样品硬度、表面形貌、元素含量与化学态等参数进行分析.结果表明,强化5 min后,通过SEM发现在样品表面出现纳米级颗粒,结合XPS测试、发现样品中Al2 O3含量明显增多,表明A...     

液膜扩散法鉴定溶液中的Fe3+和Fe2+

介绍了液膜扩散法鉴定溶液中存在的Fe3+和Fe2+.鉴于不同浓度的Fe3+、Fe2+与不同的鉴定试剂反应呈现不同的现象,通过不同反应体系的"比邻式"或"同心圆"的自然扩散实验,得出一定实验条件下Fe3+、Fe2+与不同鉴定试剂反应的最佳浓度比,可以鲜明、准确地对Fe3+、Fe2+进行鉴定,由此为中学化学实验中其他常见阳离子的鉴定提供了新思路.     

Hydrogen permeation behavior in Fe3Al-based alloy

Ultra-high vacuum gaseous hydrogen permeation experiments on Fe₃Al-based alloy were performed in the temperature range of 330∼450°C with an upstream hydrogen pressure between 3. 38×10⁴ Pa and 7.28×10⁴ Pa. The results show that the hydrogen diffusivity and permeability in Fe₃Al-based alloy obey Arrhenius relationship in the experimental temperature range and the hydrogen permeation process is controlled by the lattice diffusion of hydrogen at relative high temperature. The activation energy of hydrogen diffusion in the Fe₃Al-based alloy was found to be 75 kJ/mol. Supported by the National Natural Science Foundation of China (59895157)     

The Kinetics of Hydrogen Diffusion in Ti_3Al-Based Alloy

lIntroductionAIloysbasedOI1inter111etanicsTi3AlI1avebee11stndied..inconsiderabledetaiIinrecentvearsI"'1.Theyarelegiti111ateca11didaten1ateriajsforaerospaccsysten1s,suCI1asenginesa11dairti-al11esofahydrogen-burl1ingpropulsion'syste111.Tl1erefore,theinterac…     

Hydrogen Diffusivity in Single Crystal Stoichiometric NiAl

The hydrogen diffusion behavior of single crystal stoichiometric NiAl was investigated.The results show that the dydrogendiffusivity and permeabilty of single crystal stoichiometric NiAl obey Arrhenius relationship in the experimental temperature range.The activation energy of hydrogen diffusion in single crystal stoichiometric NiAl is about 45 kJ/mol.     

硼对金属间化合物Ni_3Fe氢气诱发环境氢脆的影响(英文)

In this paper the tensile properties of both ordered and disordered Ni-24Fe and Ni-24Fe-0.03%B(wt%)alloys in gaseous hydrogen was investigated.The result shows that the ductility of the disordered Ni_3Fe is significantly larger than that of ordered material in gaseous hydrogen.However,the ductility of ordered Ni3Fe doped with 0.03%B is nearly the same as that of disordered one indicating the obvious suppressing effect of boron on the H_2-induced embrittlement.Based on the segregation behavior of boron in Ni_3Al,it is proposed that the suppressing effect of boron in Ni_3Fe on the H_2-induced embrittlement is attributed to the segregation of boron on grain boundaries,thereby reducing the hydrogen diffusivity along the grain boundaries.     

冷轧退火Fe3(Al，Cr，Zr)金属间化合物的室温环境脆性及择优取向

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赭石的不同煎出液中Fe2+、Fe3+含量测定研究

目的:建立赭石的水煎液和醋煎液中Fe2+、Fe3+含量分别测定的方法。方法:在pH值为3~5之间,波长为396 nm,以邻二氮菲作显色剂,用紫外-可见分光光度计测定铁含量;在波长为510 nm处测定Fe2+的含量;再由2个浓度之差求得Fe3+的含量。结果:赭石的醋煎液和水煎液中铁含量有明显不同。结论:该方法精度好,回收率大于90%,操作简便,可用于Fe2+、Fe3+含量的测定。     

储氢合金粉表面电化学修饰镍磷合金的研究

作为镍氢电池负极活性物质,储氢合金是影响电极电化学性能的主要因素,对储氢合金进行表面处理可有效提高镍氢电池电极的电化学性能。实验采用电化学方法对储氢合金表面进行镍磷合金修饰处理,通过扫描电镜(SEM)及EDX能谱对电极表面进行了表征分析,测定了处理前后镍氢电池在1.5C和2C下的大电流放电性能,通过交流阻抗和循环伏安曲线对处理后电极进行了评价。测试结果表明,通过电化学修饰镍磷合金,储氢合金电极的大电流放电性能有所提高,电化学阻抗减小,循环寿命增长,有效提高了镍氢电池的性能。     

有序度对Ni_4Mo合金在氢气中脆性的影响(英文)

1IntroductionNickel-based alloys containing 20 -30 wt % Mo isknown to be essential for corrosion resistance in re-ducing media[1],especially for resistance to HCl at alltemperatures and concentrations[2]. However , uponexposure to elevated temperatures in the range of600 -800 ℃,these alloys suffer an al most completeloss of roomtemperature ductility as a result of long-range ordering (LRO) to Ni4Mo .It is considered thatthe loss of ductility mainly results from the environ-mental embrittle…     

硼对金属间化合物Ni3Fe氢气诱发环境氢脆的影响

In this paper the tensile properties of both ordered and disordered Ni-24Fe and Ni-24Fe-0.03%B （wt%） alloys in gaseous hydrogen was investigated. The result shows that the ductility of the disordered Ni3Fe is significantly larger than that of ordered material in gaseous hydrogen. However, the ductility of ordered Ni3Fe doped with 0.03%B is nearly the same as that of disordered one indicating the obvious suppressing effect of boron on the H2-induced embrittlement. Based on the segregation behavior of boron in Ni3A1, it is proposed that the suppressing effect of boron in Ni3Fe on the H2-induced embrittlement is attributed to the segregation of boron on grain boundaries, thereby reducing the hydrogen diffusivity along the grain boundaries.     

原子吸收光谱法测定TC11钛合金中微量Fe

将TC11钛合金试样经盐酸-硝酸在加热的条件下滴加氢氟酸溶解后,加入锶盐以消除基体钛及其它元素对铁的干扰,采用原子吸收分光光度法对其中铁元素含量进行了测定.结果显示,其RSD为0.7%,加标回收率为99.99%～100.05%,微量Fe的质量百分含量为0.020%.该方法测定速度快,灵敏度高,干扰小,测定结果可靠.