Tool wear compensation in 3D micro EDM based on the scanned area

Complex 3D micro-structures can be fabricated layer by layer in alloys by micro electrical discharge machining (EDM) using simple shaped electrodes. However, electrode wear is a serious problem which significantly affects machining accuracy. The electrode wear compensation method is a key issue in micro EDM milling and effectively solves this problem. This paper proposes a new compensation method based on the scanned area (BSA) in each layer machining. The new method is integrated with a CAD/CAM system to generate 3D micro cavities. Experimental results have been compared with those using the uniform wear method (UWM) and those using a combination of linear compensation with UWM. It was found that using the proposed method machining efficiency was improved and tool wear ratio was reduced.