Quality Optimization of Micro-Hole In Laser Drilling

Abstract

Laser drilling is a popular non-traditional machining technique for producing large numbers of cooling holes of various sizes (<1mm) and angles in modern aerospace gas turbine components such as turbine blades, nozzle guide vanes, combustion chambers and after burners. Though the rate of production of micro-hole (i.e. productivity) is very high but the quality of hole (such as straightness, circularity, HAZ) is very poor due to unique nature of the process. In the present study, SEM analysis is carried out on the micro-holes produced on a medium carbon steel specimen based on Taguchi’s orthogonal array and finally recommendation is made for optimum selection of process parameter such as: pulse frequency, pulse width and assist gas flow rate for getting a good quality hole.