Improved plasma sprayed thermal bond coat system

摘要

PROBLEM TO BE SOLVED: To provide a method for forming a thermal barrier coating system with higher performance and lower cost than conventional coating methods, which does not give any adverse effect to environmental resistance and exfoliation resistance, by employing a thinner bond coat than conventional ones. ;SOLUTION: The coating system (20) comprises a ceramic layer (26), and an environmentally resistant bond coat (24) of β-NiAl for making the ceramic layer adhere to the surface of a component. A thin aluminum oxide scale (28) is formed on the surface of the β-NiAl bond coat during heat treatment. It may have an additional diffusion layer of aluminide formed under the ceramic layer (26). The bond coat of β-NiAl can contain alloy elements such as hafnium, chromium, and zirconium as well as nickel and aluminum. The powder of β-NiAl is supplied as powder with particle sizes of 20-50 μm. The β-NiAl powder is deposited by means of an atmospheric plasma spraying technology to form the bond coat with surface roughness of 400 micro inches or more.;COPYRIGHT: (C)2003,JPO