High aspects ratio micro-drilling of super-alloys using ultra short pulsed laser

摘要

The demand for high aspect ratio micro holes is growing day by day. Functional micro-holes are necessary for application areas in aeronautic, automobile, semiconductor and biomedical industries. It requires holes with high contour accuracy and minimum thermal damage. Further, the materials used in these applications are alloys, super alloys and composite materials, which are difficult to cut. Laser-machining has demonstrated outstanding capability to generate high precision micro features. The development of femto, pico-second lasers has provided a precise method for micro-fabrication. In this paper, micro-hole drilling was carried out using a 12 W, Ti-sapphire 50-100 fs laser. Holes are analysed for size and shape. It analyses the effect of pulse duration for SS-316L, Inconel-718 and Ti6Al4V. It also investigates effect of laser drilling techniques like percussion, trepanning and helical. Study concludes that with proper control on beam positioning, beam energy and pulse width one can achieve quality holes using ultrafast lasers.