共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
草酸钴的氧化条件对氧化钴及还原钴粉性能的影响 总被引:2,自引:1,他引:2
利用X-衍射、扫描电镜研究了草酸钴氧化温度对氧化产物、及其相应还原钴粉性能的影响。结果表明,氧化条件影响了钴粉的粒度,草酸钴直接还原的钴粉具有更小的粒度。 相似文献
5.
6.
7.
8.
9.
以CoSO4溶液和NaOH溶液为原料,通过将二者混合反应得到Co(OH)2沉淀,再将沉淀清洗、干燥、氢气还原得到纳米钴粉.研究了CoSO4溶液、NaOH溶液浓度以及还原温度对钴粉粒度的影响.结果表明:CoSO4溶液的初始浓度为0.8mol/L时,最终得到的钴粉BET粒度最小,达到15.8nm;钴粉粒度随NaOH溶液浓度降低而减小,NaOH溶液浓度为0.4mol/L时,钴粉BET粒度为16nm;温度对钴粉粒度影响大,还原温度越低,钴粉粒度越细,350℃还原可以得到平均粒度44nm钴粉,其形状基本为球形,分散度好. 相似文献
10.
金属钴粉的制备及应用 总被引:2,自引:0,他引:2
钴粉具有特殊的物理、化学性质和力学性能,它的应用比较广泛,国内外对金属钴粉的制备有很多研究.本文介绍了高压水喷雾法、电解法、多元醇法、γ射线辐照制备法、微乳液法、高压氢气还原法和超声雾化热分解法等钴粉制备方法的原理及其优缺点;介绍了钴粉在硬质合金、陶瓷、催化、特种工具、电子器件和电池等行业的应用现状;对我国钴粉生产的发展方向提出了建议. 相似文献
11.
乙二醇还原制备超细钴粉 总被引:3,自引:0,他引:3
以硝酸钴、碳酸钴和硫酸钴为原料,制备Co(OH)2,乙二醇为溶剂和还原剂,制备了分散性较好的球形超细钴粉。研究了不同钴盐制备的前驱体Co(OH)2对后续反应的影响及单位体积乙二醇中Co(OH)2和NaOH加入量及反应时间、温度和添加剂对钴粉的粒径和形貌的影响。用SEM和XRD测试钴粉的粒子形貌、晶体结构。结果表明,乙二醇还原的钴粉为球形,晶体结构以面心立方为主,平均粒径0.8μm,钴含量>99.5%。 相似文献
12.
Cobalt ammine sulphate solutions are reduced by gaseous hydrogen at elevated temperatures and pressures to metallic cobalt powder. The reduction is a catalytic reaction. In the refinery, the cobalt is produced in a cycle comprising a nucleation reduction with a suitable catalyst and densification reductions in which the produced cobalt powder is used as a catalyst.The kinetics of the nucleation and of the densification reductions were studied as a function of catalyst concentration, reduction conditions and solution compositions.The physical properties of the cobalt powder are controlled by the reduction procedure and addition of surface active agents. 相似文献
13.
Solonin Yurii M. Kolomiets Lyudmila L. Solonin Sergei M. Skorokhod Valerii V. 《Powder Metallurgy and Metal Ceramics》2003,42(9-10):491-496
Multicomponent intermetallic absorbers of hydrogen which are used as active materials in secondary current sources have a number of shortcomings: low electrical capacity and excessively high cost, particularly for cobalt containing alloys. A contemporary progressive method to improve the properties of electrode material is optimization of the alloy microstructure. Intermetallic hydrogen absorbers with controlled structural disorder were obtained by powder metallurgy techniques, and the effect of such on the electrochemical properties examined. 相似文献
14.
进行硫酸锌溶液净化除钴时,多采用锑盐-锌粉法。在该法技术条件基础上研究了锑盐-锌铅合金锌粉除钴的效果及其对钴返溶的抑制,认为锑盐-锌铅合金锌粉除钴在技术上可行,经济上合理。 相似文献
15.
A. P. Amosov S. M. Akhmetsagirov G. V. Bichurov A. G. Ishchuk M. A. Sal’nikov 《Russian Journal of Non-Ferrous Metals》2007,48(6):445-451
The paper contains the results of the investigation of powder raw materials (tungsten, cobalt, cobalt oxide, tungsten carbide) using scanning electron microscopy and X-ray diffraction. The effect of the raw-material characteristics on the quality of the end product (tungsten carbide) is discussed. 相似文献
16.
A. A. Kiiski P. R. Ruuskanen J. B. Rubin 《Metallurgical and Materials Transactions A》1996,27(8):2297-2304
Wear-resistant metal-matrix composite coatings with a thickness of 1.5 mm were fabricated on low-alloy steel substrates by
explosively generated shock waves. Starting materials were equivolume mixtures of WC or Cr3C2 powder mixed with either titanium or cobalt powder as a binder phase. Three different planar geometries were used, with powder
layer thicknesses varying from 1 to 3 mm. Microstructural examination showed that fully dense, crack-free coatings could be
produced with a uniform distribution of the carbides within the metallic binder phase. Shear strengths in excess of 40 MPa
were measured for coatings composed of equivolume powder mixtures of (Cr3C2 + Ti) and (WC + Ti). The weight loss of a coating produced from an equivolume (WC + Co) powder mixture measured from a two-body
abrasive wear test was significantly lower than that measured for a wear-resistant tool steel used as a reference material. 相似文献
17.
烧结合金广泛地用于制作汽车发动机阀座圈(VSI)。就增高耐热与耐磨耗性能而言,在合金化设计上,烧结合金远比常规的锻钢与铸造合金灵活。特别足,一些高钻烧结材料由于耐磨耗与耐热性高而广泛用作排气阀座圈材料。鉴于近来将发动机的A/F比(空气/燃料比)调整到比常规的贫化(即空气/燃料比增高),排气阀座圈的工作环境趋于严酷。这种A/F比贫化的趋向旨在减少排出的废气和减低燃料消耗。另一方面。也需要不断地减少使用像钴之类环境负荷高的材料。同时,钴昂贵,减低钴含母有利于节省这些材料。这篇论文详细报道了无钴、无铅及有利于环境的排气阀座矧的开发与使用。 相似文献
18.
19.
20.
The magnetic properties (magnetic induction and coercive force) of iron powder coated with nickel and cobalt as a result of chemical deposition from hypophosphite electrolytes are studied. Thermogravimetry, differential thermal and x-ray phase analyses are used to study in detail the kinetics and mechanism of high-temperature oxidation in air (up to 1200°C) for the original and coated powders. The phase composition of oxide films on specimens annealed at all temperatures of the DTA-curve peaks is determined. The possibility of increasing the high-temperature oxidation resistance of iron powder coated with nickel or cobalt is demonstrated. 相似文献