微细金属镍粉的制备及其在导电浆料中的应用
文献类型：学位论文
| 作者 | 白柳杨 |
| 学位类别 | 博士 |
| 答辩日期 | 2009-05-27 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 过程工程研究所 |
| 导师 | 袁方利 |
| 关键词 | 微细镍粉 电极材料 镍包覆复合粉体 高频等离子体 液相还原 |
| 其他题名 | Preparation of Fine Nickel Powders and Their Applications in Conducting Paints |
| 学位专业 | 化学工程 |
| 中文摘要 | 微细镍粉在磁性材料、催化剂、电池材料、表面涂层材料、硬质合金等许多领域具有广泛的应用。微细球形镍粉具有导电性好、熔点高、价格便宜等特点,是理想的贱金属电极材料。尤其是随着多层陶瓷电容器（multilayer ceramic capacitor, MLCC）等电子元器件的发展，作为电极材料的微细镍粉用量越来越大，同时对产品的要求也越来越高。我国镍资源相对匮乏，镍被视为战略金属，目前，很多领域需求的高端镍粉主要依靠进口，因此，开发具有自主知识产权的制备微细镍粉的工艺并推进其产业化，对我国镍资源的高效利用和促进MLCC等产业的国产化进程都具有重要的意义。 本论文主要围绕微细镍粉的制备工艺进行研究，并将产品镍粉应用于导电浆料中。主要的研究工作及结果如下： （1）高频等离子体法制备微细球形镍粉。分别采用羰基镍粉和碱式碳酸镍/氢氧化镍为原料，在氢气提供还原气氛的条件下制备微细球形镍粉。采用碱式碳酸镍/氢氧化镍为原料，与直接采用金属镍粉为原料相比可以降低成本，另外，碱式碳酸镍/氢氧化镍的还原副产物为水和二氧化碳，保证了产品镍粉的纯度，也不会污染环境和损害设备，有利于实现绿色生产。热力学计算和XRD结果显示，产品为纯相的金属镍粉。EDX结果显示，镍粉中的氧含量为1%左右。FESEM结果显示产品为分散较好的纳米球形镍粉，颗粒尺寸为50-100 nm左右，产品镍粉的振实密度大于3.7 g/cm3，实验室规模的产量可以达到300 g/h。 （2）液相还原法制备微细金属镍粉。采用无钠的水合肼还原体系，制备无钠金属镍粉，以消除碱金属离子对镍粉在电极应用中的不良影响。产品镍粉为分散很好的球形颗粒，粒度分布均匀。此工艺可以生产200 nm以上的的系列产品。XPS结果显示，此工艺在一定程度上解决了传统液相还原法制备镍粉表面富含羟基的问题。另外，借鉴贵金属粉体在形貌控制中的成功经验，制备规则的微细镍晶体，并在实验结果的基础上提出了正二十面体晶体层层包裹的生长机制。采用乙醇和水合肼组合还原的方法，制备了分散较好且表面光滑的纳米球形镍粉。 （3）镍包覆复合粉体的制备。将无钠的思路进一步拓展到镍包覆复合粉体中，制备无钠的镍包覆复合粉体，消除碱金属离子对镍包覆复合粉体导电性能和磁性能的影响，以提高其在导电填料和电磁屏蔽等领域的应用性能。分别采用乙醇还原醋酸镍和低温无钠水合肼还原体系制备了镍包碳纤维、镍包二氧化硅、镍包云母、镍包天然石墨等一系列产品。在低温无钠水合肼还原包覆体系的基础上提出了一步法制备镍包覆铜纳米复合金属粉体的新途径。 （4）微细球形镍粉在导电浆料中的应用研究。将液相还原法和等离子体法制备的微细球形镍粉制成导电浆料，并测试它们烧结后的导电性能。结果显示，液相还原法和等离子体法制备的微细球形镍粉都符合导电浆料应用的要求。其中液相还原法制备的镍粉中，无钠镍粉具有较小的电阻率。 |
| 英文摘要 | Fine Ni powders have been widely used in magnetic materials, catalysts, battery materials, surface coatings, hard alloys, etc. Fine spherical Ni powders have good conductivity, high melting point, and low cost, and it is the ideal base metal for electrode materials. Especially with the development of electric devices such as multilayer ceramic capacitor (MLCC), the demand for fine Ni powders becomes larger and larger. At the same time, the quality of the product should also be improved. Ni is regarded as the strategic metal in China due to its shortage. Most of the Ni powders used now are supplied from abroad. Therefore, it is of great importance to develop practical techniques on Ni powders production. In the present paper, the preparation of Ni powders and their applications in conducting paints are investigated. The main work and results are given below: (1) Preparation of fine spherical Ni powders by the RF plasma process. Carbonyl nickel powders and nickel hydroxide/carbonate were used as precursors to prepare Ni nanopowders via an RF plasma technique. The use of nickel hydroxide/carbonate as the precursor was of lower cost compared to the use of metallic Ni powders. It also guaranteed the products of high purity and the processing of environmental safety. Thermodynamic analysis and XRD characterization revealed that metallic nickel powders could be obtained. EDX result showed that the mole content of oxygen was approximately 1%. FESEM observation indicated that the products consisted of well-dispersed spheres with an average diameter of about 50-100 nm. The obtained nickel powders exhibited a tap density as high as 3.7 g/cm3. A production yield of 300 g/h was achieved in the laboratory. (2) Preparation of fine Ni powders via wet chemical reduction process. A hydrazine reduction system was proposed for the preparation of fine spherical Ni powders without alkali metal hydroxide/carbonate added, in order to get rid of the bad effects of alkali metal ions on the applications in electrode. The obtained Ni powders were well-dispersed microspheres with a narrow size distribution. A series of products could be prepared with the particle size above 200 nm. XPS analysis revealed that the hydroxide on the surface of Ni powders was much reduced compared to that synthesized via a conventional wet chemical reduction process. In addition, Ni nanocrystals were also synthesized and a layer-by-layer mechanism was proposed for the icosahedra growth. By combining the hydrazine and ethanol reduction, well-dispersed nanospheres with smooth surface were prepared. （3）Preparation of Ni-coated composites. Ni-coated composites free of alkali metal ions were also prepared in order to get rid of their bad effects on the conducting and magnetic properties. Two methods including ethanol reduction of nickel acetate and hydrazine reduction were employed. A series of Ni-coated composites including carbon fiber/Ni, SiO2/Ni, mica/Ni, and graphite/Ni were obtained. In addition, a new one-step route for the preparation of Ni-coated Cu metallic composite was proposed. (4) Study on the applications of Ni powders in conducting paints. Conducting paints were made from the prepared fine spherical Ni powders, and electrodes were made using these conducting paints. Results showed that fine spherical Ni powders prepared from both RF plasma and wet chemical reduction met the requirement of electrode materials. Ni powders without Na ions exhibited better electrical conductivity than those with Na ions. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 147 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1313]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 白柳杨. 微细金属镍粉的制备及其在导电浆料中的应用[D]. 过程工程研究所. 中国科学院过程工程研究所. 2009. |
入库方式： OAI收割
来源：过程工程研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。