Electrode feed path planning for multi-axis EDM of integral shrouded impeller

Multi-axis electrical discharge machining is an effective approach for machining integral shrouded blade components. The key is to plan an interference-free and optimized tool electrode feed path while keeping the size of the electrode as large as possible. In this paper, a new electrode feed path planning method called tangent tracking was proposed. The electrode feed path planning can be formulated as a dynamic programming problem which consists of N discrete steps. In each step, the electrode posture optimization can be divided into pre-optimization and re-optimization. By using such a planning method, the electrode can have a smoother feed path and a larger size as compared with traditional methods. The machining tests for an integral shrouded impeller show that the tangent tracking method not only improves the machining efficiency, but also reduces the number of electrodes used.