Platinum-modified diffusion aluminide coatings on nickel-base superalloys. Final report, June 1985-June 1988

Technical Report · Mon Mar 01 04:00:00 EST 1993

OSTI ID:6207764

Kim, G M; Meier, G H; Pettit, F S

Conventional and platinum modified diffusion aluminide coatings on some state-of-the art single crystal and polycrystalline nickel-base superalloys have been compared in tests designed to establish conditions representative of those existing in gas turbines operating over a range of applications. Resistance of these coatings to oxidation, high temperature hot corrosion, and low temperature hot corrosion have been compared. Platinum has been found to significantly improve the resistance of diffusion aluminides to all of these forms of degradation but the improvement with regard to low temperature hot corrosion is not as great as in the case of the other two forms of attack. Substrate composition has been found to exert a very significant effect on the lives of coatings in the high temperature tests. In the case of high temperature oxidation, elements such as Hf are important in that they extend coating lives whereas for high temperature hot corrosion the type and concentration of refractory elements are significant factors affecting coating lives. A limited number of experiments have indicated intermittent hot corrosion exposures degrade the subsequent cyclic oxidation resistance of Pt-aluminide coatings.... Superalloys, Nickel-base superalloys, Oxidation resistance, Platinum coatings, Single crystals.

• Research Organization: Pittsburgh Univ., PA (United States). Dept. of Materials Science and Engineering
• OSTI ID: 6207764
• Report Number(s): AD-A-263597/7/XAB; CNN: DAAG46-85-K-0008
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COATINGS
CORROSION RESISTANCE
CRYSTALS
ELEMENTS
EQUIPMENT
GAS TURBINES
HAFNIUM
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INTERMETALLIC COMPOUNDS
LIFETIME
MACHINERY
MATERIALS
METALLURGICAL EFFECTS
METALS
MONOCRYSTALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
OXIDATION
PLATINUM
PLATINUM METALS
SERVICE LIFE
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0400-1000 K
TRANSITION ELEMENTS
TURBINES
TURBOMACHINERY