Production and Properties of Oxidation-Resistant Spark Coatings on Titanium Alloys

Abstract

The paper examines the formation, on titanic alloys, of spark-deposited coatings from Ni–Cr–Al alloy pressed and sintered in vacuum. The electrospark parameters are optimized to obtain coatings with a thickness to 30 µm, density not lower than 80%, and hardness about 8 GPa. It is shown that spark-deposited coatings on VT6 and VT22 alloys permit increase in their oxidation resistance by a factor of 1.5 to 2.5 during isothermal holding at 800 ⁰C. This increase is due to the formation of oxidation-resistant titanium phases on coatings, which prevent the diffusion of elements from air into the coating.