Scope of non-conventional machining techniques for fibre metal laminates: A review

Fibre metal laminates are one of the most popular structural materials for the automotive and aviation industry. Fibre metal laminates comprise alternating laminae/sheets of metallic alloys and fibre-reinforced polymer matrix. The amalgamated stackup imparts superior mechanical properties of high tensile/ shear strength, excellent stiffness-to-weight ratio, fatigue resistance, impact strength, apart from being lightweight. For obtaining the desired shape and size of components from these laminated materials, forming and machining are vital processes. Due to the contrasting machinability of the monolithic metals and alloys, as compared to that of the fibre-reinforced polymer matrix materials, machining is very challenging. Conventional machining processes like drilling and milling are known to cause delamination in the laminates, heat affected zones at the edges of the monolithic metallic layers and accelerated tool wear. To overcome the challenges of conventional machining, non-conventional machining processes like abrasive water jet machining, laserjet machining, electric discharge machining, and ultrasonic machining are being employed with great success. In this review article, the non-conventional machining processes for fibre-metal laminates, the parameters affecting the machining have been covered.