Stress analysis of elastic-plastic contact damage in ceramic coatings on metal substrates

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1996.tb09024.x· OSTI ID:413313

Fischer-Cripps, A C; Lawn, B R; Pajares, A; Wei, L ^[1]

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1. National Inst. of Standards and Technology, Gaithersburg, MD (United States). Materials Science and Engineering Lab.

An elastic-plastic analysis of damage in ceramic coatings on metal substrates from contacts with spherical indenters is made using finite element modeling. Computations are carried out specifically for plasma-sprayed alumina:titania on a soft steel. The algorithm assumes an elastic sphere with frictionless contact on a flat elastic-plastic layered specimen, and incrementally evaluates the expanding contact field as a function of applied load. Two key aspects of the contact field are examined: (i) the indentation stress-strain curve; (ii) the damage zone geometry. Composite coating/substrate indentation stress-strain curves are computed for two coating thicknesses, using input material parameters from iterative fits to data from control tests on free-standing coating and substrate materials. Contours of principal shear stresses, most notably those contours corresponding to yield zone boundaries in both the softer substrate and the harder coating, are mapped out in the fully plastic region. Corresponding distributions of tensile stresses are also mapped out, and are shown to correlate with the locations of transverse fractures in the coating. General implications concerning material and geometrical design of ceramic-based layer structures are discussed.

• Sponsoring Organization: DGICyT (Spain)
• OSTI ID: 413313
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 10 Vol. 79; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
DEFORMATION
ELASTICITY
FINITE ELEMENT METHOD
FRACTURES
HARDNESS
MATHEMATICAL MODELS
PLASMA ARC SPRAYING
PLASTICITY
STEELS
STRAINS
STRESS ANALYSIS
STRESSES
TITANIUM OXIDES