微能电脉冲场单道扫描加工的积分作用机理及规律研究

Micro-electrical discharge machining (Micro-EDM) is being not able to meet the realistic requirement of increasing surface integrity and machining efficiency simultaneously, especially for mesoscopic feature. One of the most important reasons is that both positive and negative poles appear arc shape during single-channel scanning manufacturing. The phenomenon and its effect on precise erosion ability have been verified by many famous research institutes in the world. A lot of scholars have done much work in order to keep the shape of tools. They intend to reduce the effect and limitation of arc shape on precise erosion ability. Great result has been obtained. However, they have not established accumulative effect model for single-channel scanning manufacturing process based on mechanism. The current research is not able to explain the essence of arc shape on both poles with scanning process. The project is mainly to explore and explain the reason of arc shape on both poles. It will refer to some important corresponding research achievements in the world, including that of the project team. The combination of establishing model and experiment research will be adopted for simulation and analysis. It will extract polarity erosion feature and varying rules with energy of single electrical pulse. The model of integration mechanism on minutiae feature will be deduced about micro-energy electrical pulse field and geometric field at both poles during single-channel scanning manufacturing. Afterwards, the cause and rules of arc shape will be analyzed. Some technical methods will be explored to control arc shape and improve precise erosion ability. The project has feasible technology. Furthermore, there has been of good preparation for both experiment and team.

微细电火花扫描加工技术已不能同时满足日益提高的介观特征的表面完整性和加工效率的现实需求，其中一个重要原因是正、负两极在单道扫描加工过程中出现的钝圆现象。该现象及其对精密蚀除能力的影响已在国内外很多著名科研机构的研究中得以证实，国内外学者对此开展了大量研究，虽然成效显著，但并未从机理上建立单道扫描加工过程的累积作用模型，还不能从本质上分析两极轮廓随扫描轨迹而出现的钝圆现象。本项目主要针对此基础问题，参考国内外最新研究成果及项目组已有研究基础，通过建模仿真分析与实验研究相结合的方式，发掘单位微能电脉冲场的极性蚀除特征及其随脉冲能量变化的规律，建立连续微能电脉冲场在单道扫描加工过程中对正、负两极放电几何场的积分作用模型，进而分析两极产生钝圆现象的根源及各主要影响因素累积作用的规律，并探索控制钝圆现象、提升精密蚀除能力的工艺方法。本项目技术可行、科研条件和人才团队均具有良好的基础。

现有微细电火花加工技术已不能同时满足更高的表面完整性和加工效率的现实需求，其中一个重要原因是正、负两极在单道扫描加工过程中出现的钝圆现象，这限制了众多关键微小精密零件性能的验证、提高和广泛应用，制约甚至阻碍了某些重大科学技术的研究进展。本项目主要针对此基础问题，通过建模仿真分析与实验研究相结合的方式，研究了其产生的机理，揭示了单位微能电脉冲场的微纳极限蚀除特征及其随脉冲能量变化的规律，建立了微能电脉冲场在单道扫描加工过程中对正、负两极放电几何场的积分作用模型，自主编制了微细电火花单道扫描加工仿真软件，进而分析了两极产生钝圆现象的根源和规律，找出了形成钝圆现象的主要影响因素，并探索了控制钝圆现象、提升精密蚀除能力的工艺方法。通过分别开展实芯电极和中空电极在不同主要影响参数下的放电加工对比实验，加工出了不同钝圆形貌的微小特征，与自主仿真软件的仿真分析结果相符；同时，还加工出了直径分别为20μm、30μm，高25μm的圆柱特征，其拐角半径小。这有效的实现了微小特征底部拐角钝圆形貌的复现和有效抑制，验证了本项目对微细电火花单道扫描加工形成钝圆现象机理的分析的正确性。此项研究有利于为进一步发挥该技术在细节特征精度、表面质量、效率等方面的潜力和优势提供理论依据和指导规律，推动更精密的放电加工机理与工艺的深入研究，为后续探索纳米级精密放电蚀除机理与工艺的研究具有重要现实意义。