Laser cleaning of copper in air and nitrogen atmospheres

We examine the physical and chemical processes occurring on the surfaces of copper and copper-alloy objects that are laser-cleaned using a Smart Clean 2 (El. En., Italy) pulsed YAG:Nd laser and a commercial MiniMarker2 M20 ytterbium pulsed fiber-optic laser, both with emission wavelengths of 1064 nm. We show that discoloration of the copper surface can be mitigated by performing the laser treatment in a nitrogen atmosphere.