Formation and study of electrospark coatings based on titanium aluminides

Coatings containing Ti-Al intermetallics are fabricated by the electrospark deposition of titanium on aluminum and aluminum on titanium. The microstructure and composition of the grown coatings is studied by scanning electron microscopy, X-ray diffraction, and S-ray microanalysis. It is found that the surface layer formed in argon mostly contains the α-TiAl3 intermetallic independent of the duration and frequency of discharge pulses. The γ-TiAl and α2-Ti3Al phases can be obtained by aluminum deposition on titanium followed by the subsequent deposition of a second titanium layer. Aluminum oxide and titanium nitride are additionally formed during the deposition of electrospark coatings in air.