Corrosion behavior of laser-alloyed copper with titanium fabricated by high power diode laser

Laser surface alloying of commercially pure copper (cp Cu) with preplaced Ti powder has been successfully achieved using a high power diode laser. All laser-alloyed specimens have corrosion potentials in between that of cp Cu and commercially pure titanium (cp Ti) and their corrosion current densities are lower than that of cp Cu. Particularly, the specimen with 85 wt.% Ti fabricated at scanning speed of 35 mm/s shows the highest corrosion resistance, that is, about 150 times that of cp Cu and very close to that of cp Ti. Improvement of corrosion resistance is attributed to presence of Ti in the intermetallic and metallic phases for forming the protective oxide.

► Laser surface alloying of cp Cu with 25–85 wt.% Ti was achieved using a diode laser. ► Surface hardness of laser-alloyed Cu is 8.8 times that of cp Cu. ► Laser-alloyed specimens have corrosion potentials in between cp Cu & cp Ti. ► Corrosion current densities of laser-alloyed specimens are lower than that of cp Cu. ► Presence of Ti in intermetallic & metallic phases improves the corrosion resistance.