Laser Drilling Series:

Trepan DrillingGeneral Overview

What is Laser Drilling?

• Laser drilling has made it possible to drill very small; precisely tapered; unusually shaped and blind holes in a variety of objects.

• A single set-up can drill different shapes and sizes of holes over 3D surfaces, even on difficult to process materials.

• They can create discrete pulses with controllable temporal profile, energy and peak power.

Small holes drilled sample

Common Drilling Types

The most common types of drilling techniques include:– the trepan drilling technique– the percussion laser drilling method

Percussion Technique

• In the percussion technique, there’s no relative motion between the part to be cut and the laser beam during the drilling process.

• It is possible to drill holes with diameters between 5µm and 1000µm.

• This technique can allow for special drilling processes such as the “on-the-fly drilling”.

Percussion Technique II

• This method has increased the drilling speed.• It is used to produce turbine engine

components.• The accuracy and the quality of the drilled

parts depend on the interaction between the material and the laser beam.

Trepan Technique I

• The trepan drilling technique is used in applications that require that a diameter tolerance, which is almost half that of the percussion drilling technology.

• There should be a motion system that can allow for relative motion between the laser light to that of the section to be cut.

Trepan Technique II

• The system should be able to produce an accurate movement with a high level of programming capability.

• It can allow for the production of a comprehensive range of shapes such as complex 3D, particular shapes and immense holes.

Trepan Drilling

How is Trepan Laser Drilling Used?

• The laser trepanning is mainly used in applications where the laser beams should be smaller than the desired hole.

• There are several types of trepanning drilling, which are used in a number of manufacturing processes such as:

• (See next slide)

Simple Trepanning

• In this technique, the material to be cut is pierced with a laser beam after which the hole is cut using a single circular cut.

• In most cases, materials that have been drilled from this technique may have either start-end or start defects.

Helical Cutting Method

• In this process, a number of circular cuts are used rather than making a single piercing the material immediately.

• The material is drilled in such a way that the next hole to be drilled is always deeper than the previous hole.

• This process is repeated until the desired hole is achieved.

• This technique is mainly used where quality holes should be drilled.

Trepanning Approaches I

• The first approach focuses on translation, acceleration and deceleration and “settling” for all the laser pulses.

• With this approach, the spiral tapering can be achieved quickly.

• The initial laser penetration can occur in the interior of the perimeter.

Trepanning Approaches II

• The trepanning orbit can be completed several times.

• The main advantage of this technique is that the final pulse and the initial penetration in the trepanning sequence take place away from the perimeter of the wall.

• This prevents any form of drilling artifacts.

Trepanning Approaches III

• The second approach is mainly based on the continuous circular motion between the starting and stopping of the trepanning pulse.

• The primary advantage of this technique is that it eliminates the required acceleration and deceleration time.

Accuracy

The accuracy of the hole that have been manufactured through this technique can be determined by the: • hole diameter• Taper• recast thickness• micro cracking

For additional info, visit:

http://www.laserage.com/laser-drilling/

End of PresentationThank you!