The Effectiveness and Working of the Laser Drilling Machines

The Effectiveness and Working of the Laser Drilling Machines Laser an acronym for (Light Amplification by the Stimulated Emission of Radiation) is a technology that makes use of the coherent beam of light in stimulating molecular or electronic transmissions to the lower energy levels resulting in the emission of the photons. This is the core principle behind the working of the laser drilling machines.

The Laser Drilling Laser drilling is an automated process that can be used to make drills of alloys and composites that cannot be drilled by the use of the conventional methods. Laser drilling provides the only solution for the toughest and the hardest drilling challenges.

The use of laser drilling machine enables nearly all the solid materials ranging from metals to diamonds can be drilled by the use of a suitable laser. Time minute holes that are impossible to create with the use of mechanical processes cab be facilitated by the use of a laser. The drilling is done contact-free with the use of the extreme small optical systems that make drilling be possible at locations where the use of other methods could fail. The laser beam melts and evaporates the material. This leads to an increase in the material volume in the drill hole leading to the creation of high vapor pressure. The high vapor pressure drives the melt out of the drill hole. In laser drilling, all the laser light is reflected from the rear mirror with 30-50% of the light passing through the front mirror. The laser light continues through the shutter assembly to the angled mirror and down through the focusing length up to the work piece. The laser beam in the laser hole drilling process is coherent with a high energy content. When focused on a surface, the laser light creates the heat that is used for the hole drilling. Types of Laser Drilling Processes 1. The Single-pulse drilling and percussion drilling This method is used in the penetration of the drill holes which have a small material thickness, creating a few micrometers of depth. Percussion drilling makes use of the desired drilling depth with the thicker materials by the means of a couple of laser pulses with a low pulse energy and short pulse duration. This results in the creation of holes that are deeper, more precise and with the smaller diameter as compared to the single pulse drilling. 2. Trepanning Trepanning is a combination of the drilling and cutting process that is used in obtaining larger diameter. The starting hole is created by the use of percussion drilling with the use of several laser pulses. The laser beam the travels over the material in increasing large circular tracks over a certain work piece enlarging the initial hole with the melted material displacing downward from the drill hole. 3. Helical Drilling Helical drilling is used in the creation of large and deep drill holes of high quality. Using this process, no initial hole is created bit the drilling is done with the use of many large pulses in a circular track into the work piece. Here, the material is displaced upwards and the focus is controlled so that it always remains at the bottom of the hole. When the material has been penetrated, the laser is used to widen the bottom of the drilling and to smoothen the edges.

The benefits of using laser drilling include; – The processing of high alloy metals without difficulty – Low cost tools that do not wear – Facilitation of the angled drilling of holes even at the most difficult access areas. – There is an economic setup time – It is a non-contact process as there is no tooling wear or breakage with minimal material distortion – Produces high accuracy and consistent results – There is the ability to produce small diameter holes with high aspect ratio – Ease of programming and the adaptability to automation – Increases the production rates with flexible and faster setup times and less tooling The use of laser drilling machines enhances versatility as the same tool can be used for laser drilling and laser cutting. There is flexibility in the changeovers for the different prototypes used with small batch processing. The machine has the capacity for a higher degree of beam manipulation including the ability to drill shallow angles

and shaped holes. The laser machine has the capacity to drill multiple features simultaneously with the ability to process a wide range of materials.