Effect of NiCoCrAlYHf overlay coating on performance of Ni3Al-based alloy IC6A

A variety of experimental techniques have been used to study the effect of NiCoCrAlYHf overlay coating on the performance of alloy IC6A. The results showed that NiCoCrAlYHf overlay coating slightly influenced the microstructure of alloy IC6A by elemental diffusion, which however had no obvious influence on tensile properties at room temperature and high temperature stress rupture properties. The hot corrosion resistance at intermediate temperatures and oxidation resistance at high temperatures of alloy IC6A were improved by the NiCoCrAlYHf overlay coating, due to the changes of the oxide species and morphology, mainly NiO for uncoated specimens while α-Al2O3 for coated specimens.