Effect of laser wavelength from blue to IR on pure copper film formation by laser cladding

A laser cladding technique is widely used for various industrial applications. This process have been employed infrared lasers with wavelength of 0.8-10.6um. But it is difficult for pure copper to coat on a metal substrate with IR lasers, of which a refractivity of copper has low in IR region and very narrow process window. On one hand, the reflectance of copper drastically decreases at wavelength less than 500 nm. So, in this study, in order to compare with IR and blue diode laser, the copper layer was formed on the SUS 304 stainless steel with our laser cladding system. The copper layer was formed on SUS plate to melt and solidify the powder by blue laser irradiation. From these results, it became clear that shorter-wavelength laser was effective to form the pure copper layer even if it was the same sweep speed and power density.A laser cladding technique is widely used for various industrial applications. This process have been employed infrared lasers with wavelength of 0.8-10.6um. But it is difficult for pure copper to coat on a metal substrate with IR lasers, of which a refractivity of copper has low in IR region and very narrow process window. On one hand, the reflectance of copper drastically decreases at wavelength less than 500 nm. So, in this study, in order to compare with IR and blue diode laser, the copper layer was formed on the SUS 304 stainless steel with our laser cladding system. The copper layer was formed on SUS plate to melt and solidify the powder by blue laser irradiation. From these results, it became clear that shorter-wavelength laser was effective to form the pure copper layer even if it was the same sweep speed and power density.