Oxidation Interference in Direct Laser Nitridation of Titanium: Relative Merits of Various Ambient Gases

A comparison is performed between the relative merits of using an ambient NH 3 atmosphere or a stoichiometrically equivalent N 2 -H 2 (1:3) mixture for the direct laser nitridation of titanium samples by multipulse excimer laser ( λ = 308nm) irradiation. It is shown that the N 2 -H 2 mixture proves more effecient in inhabiting the unwanted interference of the oxidation process and that the whole process proceeds through the action of an erosion plasma on a molten layer covering the laser-irradiated area.