空心脉冲激光管内热力效应对电极反应的作用机制及微制造研究

A new micro-fabrication technology, which can deposit locally the metal material with the compound process of laser shock and electrochemical, is presented to meet the requirement of fabricating and repairing the metal parts with microstructure. Firstly, the solid laser beam is transform into the hollow laser beam by axicon-lens system. The hollow laser permeated the solution would form the virtual laser-pipe electrode, which can bring the centripetal thermal-mechanical shock effect onto the electrochemical deposited reaction. Then the quality and the locality of electrochemical deposited machining are improved. Based on the theory of mechanics and electrochemistry reaction, the electrodes reaction processes at the interface of material and liquid is investigated below the irradiation of hollow laser beam. And the mechanism of the laser-force effect, thermal-electricity effect and force-electricity effect onto the electrochemical deposition of metal ions would be studied. Based on the laser shock theory, the temporal and spatial dynamics model of circline plasma would be founded. Based on the hydrodynamic equations, the character of temperature field and the model of convective mass transfer would be discussed. This investigation will illustrate the process and mechanism of hollow pulse laser thermal-mechanical effect onto the electrochemical electrode reaction and found the relational theory model, which can provide scheme and foundation for the compound micro-fabrication of laser shock and electrochemical deposited. Finally the micro scale, localization electrochemical deposition technology will be actualized. Its application is very important in the micro-manufacture field of aeronautics and astronautics, precision instrument, IC produce, etc.

针对微米级尺寸金属零件的加工、修复和制造需求，提出将实心圆形激光束通过轴棱锥透镜转换成空心环形激光束，利用其透过溶液照射在电极表面形成的非实体光管电极，对光束中心的电化学沉积反应形成向心会聚的热力冲击作用，提高沉积质量，增强电化学反应的定域选择性。根据力学电化学原理，研究激光光管辐照条件下材料/溶液界面的电极反应过程；分析光力效应、热电效应、力电效应对金属离子结晶沉积的作用机制；根据激光冲击波理论，建立空心激光辐照在水下工件表面形成的环形等离子体的时空动态模型；根据流体动力学方程，研究空心激光管内溶液的温度场特征和对流传质模型。项目预期将揭示空心激光热力效应对光管内电极反应的作用机制，建立反应过程的理论模型，实现定域性好、材料致密度高的微米级沉积制造技术。该技术对于航空航天、精密仪器以及IC产品等领域的微细制造具有重要意义，可以为金属材料的激光电化学复合微制造提供理论指导和可行方案。

本项目针对微米级尺寸金属零件的加工、修复和制造需求，将实心圆形激光束通过轴棱锥透镜转换成空心环形激光束，利用其透过溶液照射在电极表面形成的非实体光管电极，对光束中心的电化学沉积反应形成向心会聚的热力冲击作用，影响电极的扩散传质、前置转化、电荷传递和电结晶过程，增强电化学反应的定域选择性，加快反应速度，提高了沉积层质量。根据力学电化学原理，研究了激光光管辐照条件下材料/溶液界面的电极反应过程；分析了光力效应、热电效应、力电效应对金属离子结晶沉积的作用机理。研究了电场、温度场和流场的复合能场协同作用机制，利用有限元分析方法模拟了激光与电化学复合沉积过程中的温度场特征和对流传质模型，对金属离子在电场、温度场和应力场复合作用的扩散和迁移过程进行了仿真。构建了激光电化学复合沉积制造试验系统，利用过程检测和试验分析的方法，检测了脉冲激光辐照所产生的热效应、力效应，以及热-力效应下复合沉积的电压-电流波形，研究了激光的光束能量、电化学电源的脉冲电流等加工参数对沉积质量的作用规律；实现了定域性好、材料致密度高的微米级沉积制造技术。该技术对于航空航天、精密仪器以及IC产品等领域的微细制造具有重要意义，可以为金属材料的激光电化学复合微制造提供理论指导和可行方案。