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世界钽粉生产工艺的发展 总被引:11,自引:1,他引:10
论述了国内外电容器级高压钽粉、中压钽粉、高比容钽粉的生产工艺发展过程。在钽粉生产工艺发展过程中,各种先进的装备被应用,各钽粉生产厂家围绕着钽粉比容的提高,杂质含量的降低,物理性能的优化等综合性能的改善,不断开发出新工艺、新技术,使钽粉适应并推动着钽电容器的发展。 相似文献
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本文介绍了一种扁度(径厚比)为2~20的FTP片状钽粉的微观结构,有像树叶般的原生粒子和多孔团聚的颗粒;展示了片状钽粉与粒状钽粉的化学成分、物理性能和电气特性的比较,可以看出,片状钽粉具有更耐烧结性和耐电压的特征,特别适合作为中、高压电解电容器的原材料。 相似文献
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提纯和后续加工各种钽萃取方法提供了纯度为99.5~99.8%的钽粉,表1列举了用不同方法还原的钽原料化学成分。杂质的存在使得钽不能直接投入使用,因为与杂质的沸点相比,钽的熔点是非常高的。可以通过真空或者惰气内加热来提纯芝,并且必须在还原过程中精 相似文献
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The results reported here, showing the effect of a non-continuous degassing sequence on the Al-20Si-3Cu-1 Mg powder, are a complement of previous work concerning the continuous degassing of the same powder. The degassing experiments were carried out, under high vacuum, in the temperature range 20 to 550 °C in a horizontal furnace heated at a uniform heating rate of 2.5 °C min–1. The partial pressures of the released gases were monitored and analysed during the heating phase by a computerized Edwards EQ80F residual gas analyser (RGA). RGA measurements indicate that water and hydrogen are the main degassing products. A complete degassing can only be achieved if the sample is heated up to a temperature where the chemical reactions are finished in the applied time. Thermodynamical equations alone are not enough to explain the kinetics of degassing of aluminium powders. The diffusion of aluminium through its surface oxide layer (Al2O3), described by the self-diffusion of aluminium, can explain to a large extent the kinetics of degassing aluminium powders. 相似文献
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The present capabilities of ultra high vacuum pumping systems are such that the major limitation on the attainment of ultra high vacuum is the gas loas presented by degassing and permeation of walls and of internal components. Considerable work has been undertaken, theoretically, and experimentally, to illustrate the effects of high temperature bake-out on minimizing outgassing rates but these usually refer to effects at ambient or constant elevated temperature. The present communication analyzes the rate of degassing of components when subjected to time varying heating cycles, in terms of diffusion from the bulk of the solids. It is shown that measurements of degassing rate as a function of increasing temperature can lead to detailed knowledge of the diffusion process which is important in determining the degree of bake-out necessary for individual systems. 相似文献
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Powder-Technology has developed into a significant and still increasing market. There is a demand for high quality meaning highest purity and spherical particle shape of the powder. In order to reach this aim metal alloys are melted under vacuum and atomized with intertgas. To improve the chemical purity the produced powder is treated under vacuum for instance by the static or dynamic degassing process. 相似文献
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新型真空熔炼设备的研究 总被引:1,自引:0,他引:1
对真空原位反应合成炉的工作原理及其结构特点作了系统介绍,着重解决了真空冶金熔炼中加入微粉料的难题,采用了特殊的机械传动方式,利用压力差及惰性气体携带的方法将微细粉料加入熔池中并采用变频装置增强搅拌能力。该设备是真空冶金领域中的新型生产设备。 相似文献
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介绍了30吨VOD/VHD真空精炼炉所达到的去碳保铬能力,脱氧去气能力和净化钢液的能力,结合生产实际应用专业理论知识客观地分析了该设备所达到的技术水平。 相似文献
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随着微电子封装向小型化、高密度化、高可靠性的方向发展,各行业对钎焊技术提出了高钎透率、高钎焊接头质量、材料具备高净化度等需求。高真空钎焊技术也随之日益普及、加速发展。该技术通过保障真空室的洁净度及焊接真空度,进而保障元器件的焊接质量及寿命。高真空钎焊技术要求真空钎焊炉具备高真空度、低压升率。高温下材料出气是高真空状态下炉体内的主要气源,直接影响着保真空时间。针对已组装完成的真空钎焊炉,本文进行了炉体材料表面放气、炉体压升率的理论研究计算;实际测试了真空钎焊炉所能达到的真空度及压升率;详细分析了高温下炉体材料表面出气特性;分析了不同温度对材料放气的影响;建立了一种材料放气-压升率模型,以期更好地指导真空钎焊炉设计。 相似文献