Research on Micro-Thermal Materials Processing with Pulsed Field Emission Current

脉冲场发射电流微热材料加工研究

基本信息

批准号：
14350387
负责人：
HIRATA Yoshinori
金额：
$ 10.69万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14350387/
关键词：
Field emission Precise thermal materials processing In-situ observation by SEM Carbon-Nano-Tube Vacuum breakdown Melt spot Work function FN plot 電解放出放電プラズマCVD 入熱分布

项目摘要

In this project the fundamental experiments were carried out to make clear the problems and the mechanisms of the precise thermal materials processing in micro-meter to nano-meter size with high density field emission current. The results obtained are summarized as follows :1.Theoretical prediction of field emission current from a pointed cathode coated with Carbon-Nano-Tube(CNT)The electron current distribution field-emitted from a pointed cathode, of which surface was coated by CNT on the substrate of nickel, was theoretically calculated using Fowler-Nordheim equation. The cathode shape was assumed to be axial symmetric hyperbola. The current distribution on the anode surface is varied depending on the gap length and the tip radius of the cathode.2.Measurement of field emission current from a pointed cathode coated with CNTThe field emission current was precisely measured in the range of 0.1 to 2 μm of the gap length between the cathode and stainless steel anode by applying the sinus … More oidal wave voltage. The current measured increases exponentially with increase of applied voltage. Then, the current was confirmed to be field emission current with the aid of FN plotting. The theoretical prediction of the relationship between the field emission current and the parameters such as gap length and tip radius qualitatively accorded with that by measurement. However, the current value by the measurement was higher than the calculation. It is necessary to make clear the equivalent work function of CNT and/or to treat the cathode shape carefully in the next stage of the research.3.Precise thermal materials processing by field emission currentThe precise materials processing by field emission current was tried with the CNT coated cathode in the SEM vacuum environment. The experiment showed that the melt spot was formed on the surface of stainless anode only when the electrical breakdown between both electrodes occurred. Then, it is necessary to make higher current density on the anode surface in the next stage of the research. Less

本课题开展了基础实验，以明确高密度场发射电流对微米至纳米尺寸材料进行精密热加工的问题和机理，所得结果总结如下： 1、理论研究。表面涂覆碳纳米管（CNT）的尖阴极场发射电流预测理论计算了镍基体上表面涂覆CNT的尖阴极场发射电子电流分布假设阴极形状为轴对称双曲线，阳极表面的电流分布根据阴极的间隙长度和尖端半径而变化。2.测量尖状阴极涂层的场发射电流。用CNT通过施加正弦波在阴极和不锈钢阳极之间的间隙长度0.1至2μm范围内精确测量场发射电流测量到的电流随着施加电压的增加而呈指数增加，然后借助FN图来理论预测场发射电流与间隙长度和参数之间的关系。尖端半径定性地与测量结果一致，但是测量的电流值高于计算值，有必要在下一阶段明确CNT的等效功函数和/或仔细处理阴极形状。研究.3.精密热材料加工场发射电流在SEM真空环境下对CNT涂层阴极进行了场发射电流精密加工，实验表明，只有当两个电极之间发生电击穿时，不锈钢阳极表面才会形成熔点。，下一阶段的研究需要使阳极表面的电流密度较小。