Compressive fatigue of a plasma-sprayed ZrO{sub 2}-8wt%Y{sub 2}O{sub 3} and ZrO{sub 2}-10wt%NiCrAlCoY TTBC

Journal Article · Sat Jul 01 04:00:00 EDT 1995 · Journal of Engineering Materials and Technology

DOI:https://doi.org/10.1115/1.2804544· OSTI ID:94427

Johnsen, B P; Cruse, T A ^[1]; Miller, R A; Brindley, W J ^[2]

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1. Vanderbilt Univ., Nashville, TN (United States). Mechanical Engineering Dept.
2. National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center

Design of TTBC`s for use in diesel engines requires definition of the compressive fatigue strength of TTBC`s for high numbers of applied load cycles. Here, high cycle (> 10{sup 6} cycles) fatigue (HCF) behavior of thick thermal barrier coatings (TTBC`s) was examined for applied stresses near the compressive strength of the material. Test data were obtained on four coating systems: two base materials in the unsealed and CrO{sub 2} dip sealed conditions. Free standing tubular specimens were evaluated. The data show that compressive fatigue limits exist for the four coating systems at room temperature (RT) and sealing with CrO{sub 2} improves RT fatigue life. Test results also show the ratio of the peak cyclic stress, at 10{sup 5} cycles, to ultimate compressive strength (UCS) of the Yttria Stabilized Zirconia (YSZ) tubular specimens approaches 0.90 at R = 0.6 (R = minimum/maximum compressive stress). Residual UCS increases were observed after fatigue run-outs at elevated temperatures (5 at 700 C and 1 at 400 C) for both YSZ and the cermet. Ratchetting with cyclic hardening was observed during fatigue with deformation occurring primarily in the initial portion of the high cycle fatigue life of the specimens.

• Sponsoring Organization: USDOE
• OSTI ID: 94427
• Journal Information: Journal of Engineering Materials and Technology, Journal Name: Journal of Engineering Materials and Technology Journal Issue: 3 Vol. 117; ISSN 0094-4289; ISSN JEMTA8
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CERMETS
CHROMIUM ALLOYS
COBALT ALLOYS
DIESEL ENGINES
EXPERIMENTAL DATA
FATIGUE
NICKEL BASE ALLOYS
PLASMA ARC SPRAYING
PROTECTIVE COATINGS
SPRAYED COATINGS
YTTRIUM ADDITIONS
YTTRIUM OXIDES
ZIRCONIUM OXIDES