阳极表面微弧诱发及其自组织反应动力学研究

In an appropriate electrochemical environment, the thermal electron emission could be induced in the discrete micro zone due to the uneven distribution of electron flux on the anode surface, which made oxygen molecule at the solid-liquid interface to be ionized after collision, and then oxygen plasma with "micro arc" strength and distribution characteristics would be formed. In this project proposal, an electric field would be built, using valve or non-valve metal with its oxide having the resistance value covered conductors and insulators range as the anode, and the "convex point" existing on the electrode surface lead to the uneven electric field intensity along the surface between the cathode and anode, and the spreading of high impedance deposition layer induced the competitive distribution of electron flux at the solid-liquid interface of the anode side. The effective mechanism of the non-uniform degree of geometry parameters and impedance of deposited layer on the competitive induced rule and self-organizing reaction of micro arc would be researched. The feedback and regulation mechanism of the kinetics of micro arc self-organizing reaction for the increment of micro zone resistance value due to the oxide formation under the electronic micro arc transfer condition at the liquid-solid interface would be revealed. The effective strength of the distance between electrodes, peak and valley shaped curvature radius and impedance of deposited layer on inducing the start of micro arc self-organizing reaction and influencing the survival state of the product would be characterized under the different incremental conditions of resistance values. Finally, the mathematical model of the control parameter sand survival state could be established. It would provide the support in the application of metal surface modification and special precision machining field for extending micro arc plasma.

合适的电化学条件下，阳极表面电子通量的不均衡分配可引发离散微区热电子发射，并使液固界面的氧分子经碰撞电离，形成具有“微弧”强度和分布特征的氧等离子体。据此，本项申请拟以氧化生成物电阻率量值可覆盖导体与绝缘体范围的阀或非阀金属作阳极，构建出因电极表面存在“凸起点”导致阴阳极间电场强度沿面强弱不均，和因高阻抗沉积层铺展引发阳极侧液固界面电子通量竞争分配的电场环境，研究阳极表面几何电场和沉积层阻抗的不均布程度对微弧诱发的竞争强度及微弧自组织反应的作用机制；揭示液固界面电子微弧传递条件下，因氧化物生成而导致微区电阻值增量大小对微弧自组织反应动力学的反馈与调控机理；分析在不同电阻值增量条件下，极间距离、峰谷曲率半径及沉积层阻抗分别对引发微弧自组织反应启动和影响生成物续存状态的作用强度；建立可调控参量与生成物续存状态的数学物理模型。为微弧等离子体在金属与半导体材料表面改性和微细加工领域的应用提供支撑。

合适的电化学条件下，阳极表面电子通量的不均衡分配可引发离散微区热电子发射，并使液固界面的氧分子经碰撞电离，形成具有“微弧”强度和分布特征的氧等离子体。本项目对诱发微弧等离子体的膜层组织结构和电导特性进行了分析，揭示由于膜层中微裂纹和杂质颗粒界面的随机分布引起微区阻值分布存在不均衡的涨落，微弧等离子体诱发是电流在氧化膜微区中非平衡态分布的必然结果。在缺陷微区对电流竞争分配和杂质能级逐级反馈的作用下引起缺陷微区出现丝状电流的固体电击穿行为。固体电击穿后续引发热电子发射和气体碰撞电离最终导致微弧等离子体形成。缺陷微区放电后离子晶体的融化引起电流局部均散致单个弧斑具有自生自灭的毫/微秒量级时间分布，微裂纹/杂质颗粒界面致单个弧斑具有微纳米量级的空间分布，热电子发射机制致单个弧斑具有局部热力学平衡高温等离子体的能量特性。