Final Technical Report for AFOSR Grant Number F49620-00-1-0054 (December 1, 1999 - November 30, 2002)
Final report. 1 Dec 1999-30 Nov 2002
CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND BIOCHEMISTRY
Pagination or Media Count:
The report summarizes the accomplishments by E. A. Carter during Dec. 1, 1999 to Nov. 30, 2002. New theories for describing the structure of electrons in condensed matter were developed i a quantum mechanical embedding theory allows treatment of localized electronic excited states of adsorbates or impurities on and in metals ii the most advanced kinetic energy density functional was derived, which allows for a linear scaling treatment of metallic electronic structure. Of more immediate interest to the Air Force are insights into the nature of metal-ceramic and ceramic-ceramic interfaces relevant to understanding the failure of thermal barrier coatings TBCs. Alumina-nickel interfaces in the TBCs are predicted to be the weak links in these multicomponentmultilayered coatings. These fundamental insights led to proposed changes in the composition of the alloy bond coat lying between the metal engine component and the thermal insulating ceramic. In particular, promotion of open shellcovalent character at interfaces was suggested as a design principle to increase adhesion. To this end, early transition metals doped at the alumina-nickel alloy interface were predicted dramatically increase adhesion, and replacement of alumina by silica also starkly increased adhesion to both the nickel substrate and the zirconia top coat of the TBC.
- Physical Chemistry
- Atomic and Molecular Physics and Spectroscopy