Laser-based hybrid micromachining processes: A review

Laser beam micromachining is a prominent method for micromachining applications. But it has some drawbacks like thermal stresses, uncontrolled dimensions, burrs, and spatter. Similarly, non-conventional processes like ECM, EDM, and conventional machining processes, namely turning, drilling and milling, also have limitations due to slow process and tooling costs. Researchers are continuously seeking hybrid machining, like laser-based hybrid machining methods, to improve the product's quality characteristics. Researchers have thoroughly investigated the laser-based hybrid process mechanism in the last decade and have identified different issues and control strategies to improve its performance. This paper reviews laser-based hybrid micromachining processes (LHMMP) in which LBM is combined with conventional processes and non-conventional processes in an assisted or sequential manner. Also, other energy sources assisting the laser beam machining process, viz. vibration, magnetic field, electric field, fluids, and gases, are reviewed in the current work. This paper summarizes the work performed on metals, non-metals and ceramics in the area of the LHMMP to create 3D micro features. Theoretical and experimental studies, mechanisms of machining, machining setups, and the impact of process parameters on laser-based hybrid micromachining techniques are reviewed in detail. The hybrid processes elevate the process efficiency, surface quality, tooling cost and precision of fabricated parts. In the last section of this paper, future development efforts needed in this area of laser-based hybrid machining are suggested to multiply the process utility.