Cladding

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

To cope with the stress a piece is subjected to at its interface (abrasion, corrosion .) and in its mass (elongation, flexion), it is necessary that the piece possesses characteristics of high hardness, mechanical resistance and ductibility (elongation, resistance).

Principle :

The cladding material, generally powder, is injected inside or in front of the laser beam. As soon as the superficial melting starts, powder is caught and transfers its energy to the feeding of the superficial melting. Thus, the process self-regulates, ensuring metallurgical bond, low dilution and fine structures due to fast cooling kinetics. A coating is the result of several welds made side by side.

Characteristics

Laser cladding offers new possibilities for repairing and cladding worn pieces.

This technique already used for many alloys to make anti-wear, anti-corrosion and heat barriers coatings is very different from other thermal spray processes and offers following advantages :

• It generates fine microstructures that give a better behaviour and low porosity to the clad
• High precision that reduces further machining
• Low waste of the treated parts
• No risk of coating delamination
  
• Possibility to clad new alloy compositions
• Respect of piece geometry

Industrial examples

• Stellite cladding: turbine blades, automotive valves
• Repairing of costly pieces in shipyard industry: axes, engines, catapults
• Anti-wear carbide cladding : boring tools, grinders
• Heat barriers in zirconia oxyd for aerospace industry