基于电解扫掠成形原理的整体叶盘叶根加工方法

采用片状或管状阴极电解加工(ECM)后的整体叶盘由于加工运动、阴极形状等原因在叶根处会形成一定的加工残留,影响整体叶盘的加工精度。针对叶片电解加工后形成的叶根残留,开展去除叶根残留电解加工方法的研究,解决叶根电解加工的阴极结构、加工路径设计等难题。首先,分析了叶根的残留分布情况以及叶间通道的结构,采用了电解扫掠成形加工方案。其次,设计了阴极结构与加工路径,在阴极结构上采用了扇形流道并分析了电解液流速分布,通过增加引流槽、改变倾角等措施改善了流场;对阴极的运动路径进行了规划,利用专用仿真软件对阴极运动干涉与加工程序进行了检验;通过附加叶盘转动补偿了由于不同截面内叶间通道宽度与阴极刃口尺寸不一致给加工带来的不足。最后,制作了电解加工装置并通过试验对叶根电解加工方法进行了验证。试验结果表明,该加工方法有效去除了叶根残留,加工表面质量好,加工精度达到了要求。

Processing method of blade root of blisk based on principle of electrochemical sweep shaping

The machining residual will be formed at the blade root after the blisk is processed by the electrochemical machining (ECM) method by the sheet or tubular cathode because of the influences of the movement and shape of the cathode, and it will reduce the machining precision of the blisk. In order to remove the residual at the root of the blade after electrochemical machining, the electrochemical machining scheme on blade root is carried out. Firstly, the machining scheme is determined according to the residual distribution and the structure of the channel. Secondly, the cathode structure is developed and the processing paths are calculated. The sector structure is adopted in the flow path and the flow velocity distribution is analyzed; therefore, the flow field of the cathode is improved by adding the drainage, changing the angle and other measures. The processing paths are optimized and the motion interference and the NC program are verified by the special-purpose simulation software. The lack resulting from the difference between the width of the channel and the width of the front edge of the cathode is compensated by the increase of additional rotation of the blisk. Finally, the ECM unit is made and the electrochemical machining tests about the root are carried out and verify the method. The result proves that the residual is effectively removed at the blade root and the surface quality and the processing accuracy meets the requirements.