离散悬浮阴极脉冲电化学超精复合加工回转件的跨尺度精确成型机理与方法

Precision parts with rotative surface occupy a very important position in national economy. From the sophisticated to the normal technology, it is the indispensable key parts for many products. In this topic, the parts with rotative surface are machined by electrochemical mechanical machining using the discrete and floating cathode. In the machining process, the inter-electrode gap is formed by the dynamic and static pressure of the electrolyte in between the anode and the cathode, the transition of the locating error to the machining error of parts is blocked through the cathode floating, the range of the electrochemical action is expanded and the copy function of the precision from the cathode to the workpiece is strengthened so as to modify the genetic error. Due to the cathode is floated, the cathode could be moved to the anode automatically with a small gap along with the material removal of the anode. The thickness of the monolithic cathode could be reduced by discretizing the cathode. By reducing the cathode thickness and applying the pulse effect, the flowing field of electrolyte could be improved and the machining process could be carried out with a small inter-electrode gap which is in favor of enhancing the machining accuracy. The mechanism-based problems, such as the formation mechanism and adjustment method of the inter-electrode gap and the transition characteristics and the correcting mechanism of the anode error, will be researched. The key technical problems, such as the structure and moving mechanism of the floating cathode will be solved. The mechanism and rule of the gap's influence on the roughness, waviness and roundness will be revealed. Based on above studies,the across scales precise forming technology of electrochemical mechanical machining for the parts with rotative surface could be constructed, which has important scientific significance for enriching the theory and technology of surface non-traditional precision machining.

精密回转件在国民经济中占有重要地位，是尖端到民用众多产品不可或缺的核心零件。课题提出离散悬浮阴极脉冲电化学超精加工实现回转件跨尺度精确成型，通过悬浮阴极阻断零件定位误差向加工误差传递，采用离散阴极扩大电化学作用范围，以阴极精度向阳极精度复印纠正工件遗传误差；利用极间电解液液膜支撑阴极悬浮，实现阴极随阳极材料去除以小间隙实时自动向工件表面微量进给；阴极离散化减薄单片阴极厚度，辅以脉冲效应，强化小间隙加工特性，提高精度复印能力。研究极间电解液动静压与外载平衡条件下的间隙形成机理与调整方法、离散式阴极悬浮条件下阳极误差的传递特征与纠正规律，解决离散悬浮阴极实现结构和极间间隙调控机构等方面的关键技术问题，揭示间隙变化对粗糙度、波纹度和圆度的影响机理和规律，形成电化学机械加工回转件跨尺度精确成型的理论架构与技术手段，对丰富精密光整加工理论、提高精密零件加工技术水平具有重要的科学意义和应用价值。

精密回转件在国民经济中占有重要地位，是尖端到民用众多产品不可或缺的核心零件。课题提出离散悬浮阴极脉冲电化学超精加工实现回转件跨尺度精确成型，通过悬浮阴极阻断零件定位误差向加工误差传递，采用离散阴极扩大电化学作用范围，以阴极精度向阳极精度复印纠正工件遗传误差；利用极间电解液液膜支撑阴极悬浮，实现阴极随阳极材料去除以小间隙实时自动向工件表面微量进给；阴极离散化减薄单片阴极厚度，辅以脉冲效应，强化小间隙加工特性，提高精度复印能力。研究极间电解液动静压与外载平衡条件下的间隙形成机理与调整方法、离散式阴极悬浮条件下阳极误差的传递特征与纠正规律，解决离散悬浮阴极实现结构和极间间隙调控机构等方面的关键技术问题，揭示间隙变化对粗糙度、波纹度和圆度的影响机理和规律，形成电化学机械加工回转件跨尺度精确成型的理论架构与技术手段。基于流体力学理论，仅考虑流场条件下的间隙模型。基于流体力学和电极过程动力学理论，考虑流场及电场条件下的间隙模型。进行不同阴极覆盖范围的加工结果表明，不同阴极覆盖范围具有不同的圆度误差改善能力，覆盖范围90º和120º的阴极较27º的阴极对轮廓圆度误差的修正能力高一倍，且对长波长的轮廓整平效果更加显著。说明电极覆盖范围对圆度具有重要影响，随着电极覆盖范围的增加，可使得圆度误差均化，因而改善圆度的能力显著增强。通过正交实验获得了电化学超精加工回转件的关键工艺参数，对表面粗糙度而言，机械作用占主导地位, 对圆度而言，电化学作用占主导地位。通过单因素实验，获得了加工电流、加工间隙、磨具压力、工件转速、加工时间的最佳取值。轴承作为回转件的一类代表性零部件，是本课题研究成果的主要应用对象。课题成果在精密轴承套圈加工应用当中，取得了良好效果。课题研究结果对丰富精密光整加工理论、提高精密零件加工技术水平具有重要的科学意义和应用价值。