Pulsed plasma treatment of Ti–Al coatings produced by mechanical alloying method

By means of the mechanical alloying method (MA), Ti–Al coatings were deposited on Ti substrates. Then, as-synthesized coatings were treated by pulsed argon plasma with energy up to 185 J/cm2. Irradiation of the Ti–Al MA-coating with pulsed argon plasma beams with energy density higher than 135 J/cm2 resulted in melting of the near-surface layer that in turn initiated the liquid-phase reaction between Ti and Al to form the Al3Ti compound. Melting led to smoothing of the coating structure. The coating microstructure and volume fraction of Al3Ti phase was conditioned by plasma energy. The thickness of the modified layer was several microns. Phase composition of plasma-treated coatings depended on its element composition. The plasma treatment of the Ti–Al–Si–C and Ti–Al–W–C coatings with energy of 150 J/cm2 led to formation of Ti5Si3 and TiC along with Al3Ti compound.