Coaxial laser cladding nozzle for use with a high power diode laser

Abstract

Coaxial laser cladding has generally been confined to CO2 and to a lesser extent Nd:YAG lasers. The major drawback with these types of laser cladding systems is their low deposition rates when compared to competing non-laser techniques such as PTA (Plasma Transferred Arc) and TIG (Tungsten Inert Gas) processes. This has meant that laser cladding has generally been confined to small-scale repair work, since the laser focal spot is usually limited to only a few millimetres in diameter. However, advancements in recent years in the area of the high power diode laser (HPDL) means that HPDL units, delivering rectangular focal spots, can also be utilised for laser cladding.This work introduces a new and novel coaxial-blown powder-feeding nozzle for use with a 6 kW diode laser. Wide clad tracks of the order of 20 mm wide and 1,5 mm thick, have been deposited with this nozzle, exhibiting very low dilution. Novel, adjustable features incorporated into the nozzle provide the possibility to modify the shape and angle of the exiting powder stream by the use of focussing gas jets.Coaxial laser cladding has generally been confined to CO2 and to a lesser extent Nd:YAG lasers. The major drawback with these types of laser cladding systems is their low deposition rates when compared to competing non-laser techniques such as PTA (Plasma Transferred Arc) and TIG (Tungsten Inert Gas) processes. This has meant that laser cladding has generally been confined to small-scale repair work, since the laser focal spot is usually limited to only a few millimetres in diameter. However, advancements in recent years in the area of the high power diode laser (HPDL) means that HPDL units, delivering rectangular focal spots, can also be utilised for laser cladding.This work introduces a new and novel coaxial-blown powder-feeding nozzle for use with a 6 kW diode laser. Wide clad tracks of the order of 20 mm wide and 1,5 mm thick, have been deposited with this nozzle, exhibiting very low dilution. Novel, adjustable features incorporated into the nozzle provide the possibility to modify the shape and angle...