Chemical assisted laser machining for the minimisation of recast and heat affected zone

Laser processing techniques have been widely used for high speed, high accuracy subtractive manufacturing such as cutting, drilling, milling and micro-machining. Most of these processes are based on thermal mechanisms. For the machining of metallic materials, a layer of recast and heat affected zone is normally present on the laser-machined components. This paper reports a novel technique that aims to minimize such heat affects and at the same time to improve the material removal efficiency. A relatively environmentally friendly salt solution, in contact with the beam-material interaction point, was used in this study to enable material removal to be based on laser activated thermal-chemical mechanism. It has been shown that, not only the recast layer can be removed during the processing, the material removal rate can be increased up to 300% for 316 stainless steel work piece.