High temperature oxidation and inter-diffusion behavior of electroplated Ni–Re diffusion barriers between NiCoCrAlY coating and orthorhombic-Ti2AlNb alloy

•The interfacial reactions of various specimens at 800 °C were investigated.•The inter-diffusion was effectively restrained by the Ni–Re layer.•The specimens with Ni–Re layer exhibited excellent oxidation resistance at 800 °C.

Electroplated Ni–Re film was fabricated as diffusion barrier between NiCoCrAlY coating and orthhombic-Ti2AlNb alloy. The plated Ni–Re film was intact, continuously grown and well-bonded with orthhombic-Ti2AlNb alloy. The oxidation and inter-diffusion behavior of coatings with and without diffusion barrier were both investigated in isothermal and cyclic oxidation tests at 800 °C. The results indicated that substantial inter-diffusion and rapid oxidation occurred in the coating without diffusion barrier; while deferred inter-diffusion and improved oxidation resistance were observed, and were attributed to the Ni–Re diffusion barrier.