Experimental Study in the Process Parameters in Laser Percussion Drilling

In order to service and grow in the present day of global competition, every manufacturing concern focuses mostly on two factors i.e. productivity and quality. Laser drilling is a popular non-traditional machining technique for producing large numbers of cooling holes of various sizes (less than mm diameter) and angles in modern aerotech components such as turbine blades, injector nozzles, and combustion chambers. Although the productivity of microhole in very high, the quality of hole (straightness, circularity, aspect ratio, heat affected zone, micro-crack spatter rate etc.) is poor due to unique nature of the process. In the present paper experimental investigation has been carried out using Taguchi’s L9 orthogonal array technique to optimize the main laser and process parameters to get a quality hole in case of in plane carbon steel specimen. Pulsed Nd: YAG laser beam has great ability for micro-machining of plane carbon steel materials because of high laser beam intensity at low mean beam power, good focusing characteristics due to very small pulse duration and less heat effected zones. The quality characteristics such as aspect ratio (depth / diameter), heat affected zone, spatter deposition, hole circularity are studied though scanning electron micro-scope (SEM). The specific advantages of this Taguchi’s technique of optimization are that with a very less number of experiments, optimization is possible.