Tantalum coatings formed on titanium by electrospark deposition in controlled gas atmosphere

The coatings were obtained on titanium using an automated complex for electric spark deposition in air or argon at normal and reduced pressure. Tantalum monolayers were deposited at an operating current of 0.5...2.0 A and a constant speed of movement of the electrode-tool (60 mm/min) along a straight trajectory. Local coatings in the form of lines were characterized by a thickness from 3.6...6.5 μm to 13.2...22.0 μm and a width from 0.27...0.49 mm to 0.41...0.89 mm. The layers deposited in air contained oxygen from 17.36...19.38 at. % to 40.81...47.15 at. %, as well as nitrogen from 2.07...2.61 at. % to 3.73...4.17 at. % (the rest is titanium and tantalum). The particle size varied from 72.6...74.4 μm to 118.1...202.4 μm. The surface microhardness varied from 5.4...7.7 GPa to 12.1...12.3 GPa. The use of argon made it possible to limit the oxygen content in the range of 17.99...41.00 at. %, reduce the nitrogen content to 1.65...2.20 at. %, stabilize the average splat size in the range of 89.0...121.9 μm, and reduce the microhardness to 5.3...9.0 GPa.