In situ observation of CoCr-alloy layer formation by multi laser coating

The direct injection type laser coating system using combined multi lasers, which supplies a coating powder from a center nozzle, was developed for realize of low dilution area and fine coating. A cobalt- chromium alloy (CoCr-alloy) called by Stellite, was coated on the stainless steel type 304 plate for adding the function of wear resistance, corrosion resistance and resistance to environment. The melting and solidification process for CoCr-alloy was observed in real time using synchrotron radiation imaging technique at BL22XU in SPring-8. From results, it was clarified that the CoCr-alloy melt-solidification phenomenon greatly differs for laser output power. At the output power of 60W, it was found that a minimum amount of molten pool was formed and then solidified to form the cladding layer.