Oxidation Behavior of a Ti–Al–C + Y–Al–O Two-Layer Coating

This paper examines the use of a two-layer coating consisting of a Ti–Al–C carbide-based sublayer and Y–Al–O outer oxide layer, both produced by vacuum arc deposition in reaction gases, for protecting VTI-4 Ti–Al alloy (Ti49‒11Al‒40Nb) from oxidation under high-temperature (up to 750°C) cyclic loads. To gain insight into the mechanism responsible for degradation of the coating, we have studied the structure and chemical composition of the coating during thermal cycling tests. The testing results demonstrate stability of the two-layer coating during thermal cycling tests, without macroscopic damage.