Laser machining

Menu :

• Laser principle
• Laser sources
• Applications
  • Cutting
  • Metallic welding
  • Plastic welding
  • Soldering
  • Brazing
  • Marking, engraving
  • Cleaning and surface preparation
  • Cladding
  • Surface alloying
  • Laser assisted machining
  • Laser machining

In the processes of complex 3D shape making, electro-erosion is a process of high precision but limited to only conductive materials. Besides its capacities of machining metal, laser also enables to machine complex 3 D shapes in non conductive materials like ceramics, plastics, polymers or wood.

Principle :

Laser beam shaping for a machining can be done in two ways:

• beam focussing : an optical system focuses the laser beam in a spot of a defined size which will enable by melting or vaporization of the piece to obtain geometrical shapes (for example round hole for drilling).
• Mask : this technique uses the properties of geometrical optics. It consists to obtain from an object, through an optical system, an image with perfectly controlled sizes. In this case, material is not molten but the phenomenon of photo ablation will create a breaking in the chemical bonds of the material.

Drilling of cooling pipes on a turbine blade by Nd-YAG laser.

Characteristics

There are different types of laser machining :

• Drilling: Drilling was the first laser application to be introduced the industry in 1966. Now this technology has become one of the main drilling processes, with electro erosion, ultrasounds and electron beam.
• Graining
• 3D shaping: laser can used to make grooves of various size and cone-shapes.
  

Drilling of 10 micrometer holes in plastic film

Advantages of laser drilling:

• Possibility to make holes with a small angle of inclination compared with the surface (less than 15°)
• Drilling speed
• Complex shapes in not easy accessible zones
• Drilling in hard materials like diamond, tungsten, ceramics and some Nickel based alloys.
• Precision of about 1 micrometer