Effects of segregating elements on the adhesive strength and structure of the α-Al2O3/β-NiAl interface

Karin M. Carling, Emily A. Carter

Research output: Contribution to journalArticle

83 Scopus citations

Abstract

We investigate with first-principles density functional theory (DFT) the adhesion of the Al2O3(0 0 0 1)/NiAl(1 1 0) interface as a model for the thermally grown oxide/bond coat alloy interface in thermal barrier coatings. We find that the clean interface has an ideal work of adhesion of 0.66 J m-2. We predict that S impurities reduce interfacial adhesion significantly, due to a reduction in cross-interface bonds. The presence of Pt alters the interface adhesion only slightly, while Hf dopants dramatically increase adhesion via formation of strong Hf-O bonds, as expected from Hf's open-shell character. We discuss the implications of these predictions, which are consistent with experimental observations of the effects of S, Pt, and Hf on the lifetime of thermal barrier coatings.

Original languageEnglish (US)
Pages (from-to)2791-2803
Number of pages13
JournalActa Materialia
Volume55
Issue number8
DOIs
StatePublished - May 1 2007

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Keywords

  • Crystalline oxides
  • Density functional
  • Interface segregation
  • Interface structure
  • Nickel aluminides

Fingerprint Dive into the research topics of 'Effects of segregating elements on the adhesive strength and structure of the α-Al<sub>2</sub>O<sub>3</sub>/β-NiAl interface'. Together they form a unique fingerprint.

  • Cite this