Efficient machining of diffuser-shaped film cooling holes by multi-axis fast ED-milling

This work presents a newly proposed multi-axis fast ED-milling approach for machining of diffuser-shaped film cooling holes on turbine blades. It aims to overcome the issues of alignment error and low overall efficiency raised by involving fast ED-drilling cooperated with sinking EDM. The new method fully utilizes the capabilities of fast ED-drilling and milling together with multi-axis simultaneous control functionality. The characteristics of this machining scheme are investigated, and an electrode wear compensation strategy was developed accordingly. Machining tests assure that the new method guarantees rather higher machining efficiency and comparable surface quality in contrast with layer-by-layer fast ED-milling.