Developments of non-conventional drilling methods—a review

Abstract

Demand for drilled micro-holes on difficult to machine materials have increased over the past years and non-traditional drilling processes are commonly used to fabricate such micro-holes on difficult to machine materials. This research investigates different non-traditional drilling processes, such as electro discharge, laser beam, abrasive water jet, electrochemical and electrochemical discharge drilling methods. Drilling mechanism, material removal rate/machining speed and surface finish have been analysed for every process. These analyses clearly show that vaporisation, melting, chemical dissolution and mechanical erosion are dominant material removal mechanism during non-traditional drilling. The understanding on electro discharge, laser beam and abrasive water jet drilling are more developed than that of electrochemical, electrochemical discharge and hybrid drilling processes.