2D Electrochemical Airfoil Machining Process Model

A 2D Electro-Chemical Machining (ECM) process model was developed to aid with tooling design and process optimization by simulation of the ECM process. The boundary element method (BEM) was used to numerically solve the field equations of the process model. The electrochemical anodic reaction was furnished by Faraday’s Law, which provided the relationship for the rate of dissolution at the surface of the workpiece as a function of charge transfer. Accordingly, the workpiece shape change and mass of metal removed by the machining process can be determined as a function of time. The process model includes a library of workpiece material and electrolyte combinations for predicting the electrochemical machining behavior, e.g., titanium alloy 6Al-4V and NaCl electrolytes. These metal/electrolyte combinations are of special interest in the aircraft engine industry for manufacturing heat-resistant, rotary components with complex geometry such as airfoil blades. The major features of the numerical computer program are briefly described with a selected example of machining a typical fan blade. Preliminary comparison of the numerical predictions with the nominal airfoil geometry showed good agreement and is discussed below.