Designing Damage-Resistant Brittle-Coating Structures: I. Bilayers

Published

August 1, 2003

Author(s)

P Miranda, Antonia Pajares, F Guiberteau, Y N. Deng, Brian R. Lawn

Abstract

A FEA study of coating/substrate bilayers is conducted as a foundation for damage analysis. Attention is focused on the stresses along the contact axis immediately adjacent to the bilayer interface, where radial cracking or yield in the coating, or yield in the substrate, tend to occur. The stress analysis is used to determine critical loads to initiate each damage mode in terms of basic material properties and coating thickness. Controlling material parameters are strength (brittle mode) and yield stress or hardness (plastic mode). The critical loads are shown to have a simple quadratic dependency on coating thickness, but more complex dependencies on elastic modulus mismatch ratio. Simplified explicit modulus functions afford a route to prediction of the critical loads for design purposes. Implications concerning the design of bilayers for specific applicationsare discussed.

Citation

Acta Materialia

Volume

51

Issue

No. 14

Pub Type

Journals

Keywords

bilayers, brittle coatings, cracking, critical loads, finite element analysis, plasticity

Citation

Miranda, P. , Pajares, A. , Guiberteau, F. , Deng, Y. and Lawn, B. (2003), Designing Damage-Resistant Brittle-Coating Structures: I. Bilayers, Acta Materialia (Accessed December 22, 2024)