基于界面分形特征的TiAl合金电解加工表面质量控制模型研究

轻质高温TiAl合金已应用于制作航空发动机低压涡轮叶片，由于其机械加工刀具成本太高成为制约它应用的首要因素，而电解加工作为一种无刀具损耗的高效加工方法，可用于TiAl合金加工，目前TiAl合金电解加工表面质量还不能满足发动机叶片高品质要求。本项目采用相空间重构、分形理论等非线性动力学方法研究脉冲电解加工过程工件/溶液界面状态变量的时间分布规律，建立工件溶解动力学模型，揭示工件表面成形演变规律；确立宏观工艺参数、工件/溶液界面状态变量和工件表面微观形貌三者之间的映射关系，提出表面质量预测模型；利用分岔原理和涨落理论调控工件/溶液界面结构和性质，提出电解加工表面质量控制模型，为TiAl合金航空发动机叶片高效、高精度稳定电解加工提供强有力的理论支撑。

Light-weight and high-temperature TiAl alloys have been applied in aero-engine low-pressure turbine blades. However, the high cost of machining tools is a primary factor restraining their wide application. Electrochemical machining is a high-efficiency machining technology without tool loss and can be used to the machining of TiAl alloys. Currently, the machining accuracy and surface quality of TiAl alloys can not meet the high quality requirement of the aero-engine blades. This project is to investigate temporal distribution disciplines of state variables of the workpiece / solution interface in the process of TiAl alloy pulse electrochemical machining, nonlinear dynamics methods, such as phase space reconstruction and fractal theory, will be used. Firstly, the dissolution kinetics model will be established to reveal the surface formation evolution law. Secondly, the mapping relationship among macro process parameters, state variables of the workpiece / solution interface and microstructures morphological on the workpiece surface will be built to put forward a surface quality forecast model. Finally, the structure and property of the workpiece / solution interface will be adjusted by bifurcation theory and fluctuation theory, a surface quality control model will also be proposed. This project can present a strong theoretical foundation for the high-efficiency, high-precision and stable electrochemical machining of TiAl alloy aero-engine blades.