镍基高温合金整体叶盘叶栅通道电解加工的成形精度控制

The Accuracy Control of Ni-Based Superalloy Blisk Channels by Electrochemical Machining

针对整体叶盘叶栅通道电解加工中存在的成形精度较低、余量分布不足的问题,采用叶栅通道径向电解加工方法,建立了径向进给方式中加工间隙的数学模型,得到了通道成形过程中侧面间隙的影响规律。在此基础上,分析了电极侧面裸露端、电解液特性、脉冲电流参数以及进给速度等对通道成形的影响,并给出了优化结果。同时开展了叶栅通道径向电解加工实验研究,结果显示:采用优化后的各项参数,在高温镍基合金GH4169叶盘上稳定地加工出了具有较高成形精度的叶栅通道,其叶盆、叶背面的最小精加工余量从1.82 mm和1.56 mm分别提高至2.43 mm和2.41 mm。为后续叶片精加工提供了良好的加工基础。

In order to solve the problem of lower forming accuracy and distribution insufficient of the channel finish- ing margin of blisk channel, the method of radial feeding in electrochemical machining is proposed, and a mathe- matical model of machining gap is established to study the influence rule of side gap on channel forming process, then the process parameters such as bare end of electrode, characteristics of electrolyte, pulse processing parame- ters ~ and tool feed rate are studied and optimized. With optimized parameters, the high accuracy channels of Ni- based superalloy are machined with good stability, and the result reveals that the minimum finishing margin of the concave and convex airfoil surface can be increased to 2. 43 mm and 2.41 mm at the corresponding area of the blade sampling point, in contrast to 1.82 mm and 1.56 mm with unoptimized parameters. The process environment of blade finishing is hence improved.