LAUSR

Abstract A multilayer composite coating, comprised of alternating Ni + CrAlYSiHfN sub-layers and AlxN sub-layers, was manufactured by magnetron sputtering. The multilayer is composed of β-NiAl, α-Cr and AlN phases after annealing, and their volume fractions are 72 vol.%, 12 vol.% and 16 vol.%, respectively. Due to doping with nitrides, the CTE of multilayer coating is reduced to around 12.7*10−6/K. The lower CTE mismatch allows multilayer coating to exhibit good resistance to oxide scale spalling in thermal cycling at 1100 °C. The θ-to-α Al2O3 transformation in oxide scale caused a small drop of residual stresses on multilayer coating in initial oxidation stage.