场域封闭的复杂型面进排气边电解加工基础研究

Complex surface components such as blisk and blade are the key components of aero engine. Leading and trailing edges, which are the important parts on them, determine the aerodynamic performance of complex surface. Its manufacture is the key problem in machining the complex surface. Electrochemical machining (ECM) has its own unique advantages, such as no cutting force and being independent of the material mechanical property, so it is very suitable for manufacturing the leading and trailing edges. This project proposes a leading/trailing edge manufacturing method in ECM by using a closed physical field in view of the control difficulties in accuracy and machining stability at present. And the following work will be carried out in this project. 1 A feeding mode with crossed cathodes is proposed in which the concave part cathode and convex part cathode are closed at leading and trailing edges in the entire process. This mode can decrease the change of electric field and increase the machining accuracy. 2 An electrolyte flow mode with annular channel is proposed for the entire region to make the flow field at leading and trailing edges closed. This flow mode can weaken the change of flow field and enhance the processing stability. 3 A material removal model of margin profile with small radius under multi-field coupling conditions is established through the research of the characteristics of electric field, flow field, and electrochemical field in inter-electrode gap, and the cathode will be designed. 4 Experimental investigation will be carried out and the parameters will be optimized to realize the fabrication of leading and trailing edges. Original achievements and a wide range of industrial applications will be obtained by this project.

整体叶盘/叶片等复杂型面是航空发动机中的关键零部件，进排气边是其重要组成部分，对复杂型面气动性能起决定性作用，其加工成形是复杂型面制造中的瓶颈问题。电解加工具有不受材料力学性能限制、不存在切削力等优势，非常适合难加工材料复杂型面进排气边的加工。项目针对进排气边电解加工中精度和稳定性难以控制的问题，提出了场域封闭的进排气边电解加工方法，具体将开展以下工作：1提出阴极交叉进给模式，设计全过程封闭阴极结构，减弱进排气边处电场变化，提高加工精度。2提出环形截面全区域供液方式，使间隙内流场实时封闭，减弱流场变化，提高加工稳定性。3研究小曲率半径边缘轮廓在成型演变过程中的电场、流场等特性，建立多场耦合条件下的材料溶解模型，开展阴极型面设计。4开展进排气边电解加工试验，优化工艺参数，实现复杂型面进排气边的精密稳定加工。课题研究将获得具有自主知识产权的原创性成果，具有重要的科学理论意义和工程应用价值。

叶片等复杂型面是航空发动机中最为重要的零部件，叶片进排气边曲率半径小、精度要求高，对制造提出了极高的要求。针对进排气边电解加工中存在物理场变化剧烈、加工稳定性差等问题，提出了场域封闭的复杂型面进排气边电解加工方法，减小了进排气边成型过程中的电场、流场波动，实现了进排气边精密成型；提出了流域封闭的全轮廓均匀供液流场形式，建立了多场耦合复杂型面电解加工模型，阐明了极间间隙沿程分布规律，提高了加工稳定性；开展了小曲率半径轮廓交叉阴极设计研究，明晰了交叉点、交叉量等参数对间隙影响规律，获得了进排气边交叉阴极设计方法；开展了复杂型面精密电解加工应用研究，研制出新型航空发动机扭曲静子叶片、新型弹用发动机静子叶片、大型运输机辅助动力装置扩压器试件、第四代航空发动机整体叶盘扇段试件，实现了复杂型面全轮廓精密加工，显著提高加工精度和效率，降低制造成本。项目发表学术论文10篇，其中SCI收录9篇；申请发明专利9项，其中已授权5项；参与制定了2项行业标准；项目负责人获中国航空学会青年科技奖、国防科技创新团队奖（第14）；项目负责人入选教育部长江学者奖励计划青年学者、江苏省六大人才高峰高层次人才和青蓝工程优秀青年骨干教师等人才工程。