Metal oxide (Ti,Ta)-(TiO2,TaO) coatings produced on titanium using electrospark alloying and modified by induction heat treatment

Metal oxide coatings (Ti,Ta)-(TiO2,TaO) on VT1-00 cp-titanium and VT16 titanium alloy (Ti-3Al-4.5 V-5.0Mo) were formed by electrospark alloying (ESA) at an operating current from 1 to 2.5 A and subsequent induction heat treatment (IHT) with the duration from 30 to 300 s at the temperature of 800 °C. ESA at a high operating current I = 2.5 A and subsequent IHT with a long exposure time t = 300 s ensured the formation of coatings with a high content of tantalum (about 4.5-5%) and tantalum oxide TaO (about 7-8%). The resulting coatings were characterized by high hardness of 9.5-15 GPa and elastic modulus E of 450-700 GPa.