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Mo(Si,Al)2粉末材料的机械合金化合成 总被引:1,自引:0,他引:1
通过机械合金化由MoSi2,Mo和Al粉末合成了Mo(Si1-x,Alx)2粉末材料,用X射线衍射分析了相的变化和粉末的晶粒度,用扫描电镜观察球磨后的粉末形貌与粒度,并根据Burgio模式估算了生成Mo(Si,Al)2相的球磨能.结果表明MoSi2,Mo和Al混合粉经高能球磨5 h后生成了MoSi2和Mo(Si,Al)2,没有单质粉末剩余,也无Al-Mo中间相产生;球磨40 h后的粉末粒度为亚微米级,晶粒度在21 nm~40 nm之间,Mo(Si,Al)2相的机械合金化合成机理为类自蔓延反应,其生成所需的球磨能量约为15.4 kJ/g. 相似文献
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采用电感耦合等离子体质谱仪,运用钴内标法测定海绵锆中铅、钒、铝、锡、铜的质量分数,通过优化等离子体条件减少质谱干扰,采用内标法校正基体效应和信号漂移。工作曲线的相关系数大于0.999。运用ICP-MS法对其进行测定,其测定结果的精密度、准确度满足分析要求,与ICP-AES法比较,符合要求。 相似文献
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直读发射光谱法测定银硼钼锡铅的载体缓冲剂研究 总被引:1,自引:0,他引:1
研究推荐以Al_2O_3、K_2S_2O_7、SiO_2、BaCO_3、NaF、S、CaCO_3、Fe_2O_3为主要组分的载体缓冲剂,通过与地球化学样品中待测元素发生热化学反应生成氟化物、硫化物确保其蒸发浓集率,与样品基体生成难以挥发的硅铝酸盐降低其干扰程度。在此基础上建立了直读光谱快速测定Ag、B、Mo、Sn、Pb的单电极载体蒸馏法,采用国家一级标准物质校准工作曲线及分析结果的量值溯源,检出限分别为Ag 0.006μg/g、B 0.84μg/g、Mo 0.08μg/g、Sn 0.19μg/g、Pb 0.59μg/g,待测元素结果的精密度≤8.14%、准确度≤0.089,满足多目标地球化学调查、生态地球化学评价等要求。 相似文献
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M. Moukassi M. Gougeon P. Steinmetz B. Dupre C. Gleitzer 《Metallurgical and Materials Transactions B》1984,15(2):383-391
In order to investigate the reduction mechanism of wustite in the presence of impurities usually met in the ironmaking industry,
single crystals have been prepared with Mg, Mn, Ca, Al, and Si as dopants. The amounts of dopant in the lattice is around
4,4,2.5,0.5, and 0.01 mol pct, respectively, at 800 ‡C. For reduction with pure hydrogen, from 600 to 950 ‡C, Ca is the most
efficient for accelerating the process at high degrees of reduction (75 pct) Mg and Mn are also active in this respect. Al
has only a slowing down effect. Si also slows down the reaction at temperatures between 600 <T < 850 ‡C, but it becomes accelerating atT > 850 ‡C. In the presence of 20 torrs of water vapor in the gas, Mg and Mn are less efficient and unable to prevent the same
slowing down of reaction observed with pure wustite at around 850 ‡C and classically called the ‡rate minimum‡. Our interpretation
of these results is mainly based upon the observations of microstructures of partly reduced crystals which show a change in
the texture of the iron produced which can be correlated with the reduction rate. These observations lead to a possible explanation
in terms of the role of inclusions of impurity oxides on the sintering process of the metal, correlated with their ability
to dissolve into the wustite lattice. However, this suggestion cannot apply in the case of Si at low temperatures, and this
element is therefore supposed to play a role in the stages of reaction associated with the surface of the crystals. 相似文献