this study is focused on investigating the parameters of laser percussion drilling process of nickel-base super alloy inconel 718 with thickness of 1 mm. fiber laser with the power of 500 watts was used as the laser source. laser pulse frequency, duty cycle, laser power, focal point position, were assumed as the laser drilling process variables. the hole geometry features, i.e. entrance hole di...

Laser drilling has emerged in the last five years as the most widely accepted method of creating microvias in high-density electronic interconnect and chip packaging devices. Most commercially available laser drilling tools are currently based on one of two laser types: far-IR CO2 lasers and UV solid state lasers at 355 nm. While CO2 lasers are recognized for their high average power and drilli...

Results of spectroscopic temperature measurements of the laser-induced plasma generated during percussion drilling with a high power diode-pumped, pulsed Nd:YAG laser are presented. SAE 52100 steel was drilled with varying average powers. Helium and oxygen were each used as the shield gas. Emission spectra were collected with a monochrometer and an intensified charge coupled detector connected ...

1. Abstract Modem aerospace gas turbines require large numbers of small diameter holes « 1 mm) to provide cooling in the turbine blades, nozzle guide vanes, combustion chambers and afterburner. A typical modem engine will have 1 00,000 such holes. Such holes can be successfully produced by laser trepanning, but this is a relatively slow process compared with laser percussion drilling. With perc...

Abstract The influence of the laser fluence on quality percussion-drilled holes was investigated both experimentally and by an analytical model. study reveals that edge drilled microholes depends reaching rear exit hole changes with number pulses applied after breakthrough. minimum must reach hole’s in order to obtain high-quality stainless steel found be 2.8 times ablation threshold.

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 ...

This paper studies systems of partial differential equations modelling laser percussion drilling. The particular phenomenon considered in detail is the ejection of the thin layer of molten material. This thin layer is modelled as an inviscid flow between the fluid surface and fluid/solid interface, both of which are unknown moving boundaries. Through a regular asymptotic expansion, the governin...

Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm−2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic ...