Accession Number : ADA133056

Title :   A Molecular Orbital Model of Intergranular Embrittlement.

Descriptive Note : Interim rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE CENTER FOR MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Eberhart,M E ; Johnson,K H ; Latanision,R M

PDF Url : ADA133056

Report Date : 20 Sep 1983

Pagination or Media Count : 16

Abstract : A current atomistic model for intergranular embrittlement is reviewed. It is argued that this model is incomplete and cannot explain the observed sudden onset of embrittlement at critical grain boundary concentrations of segregated impurities. It is suggested that the existence of chemical bonds lying within the grain boundary and parallel to it would complete the model. SCF-Xalpha-SW molecular orbital calculations have been performed on a cluster designed to model the impurity-impurity interactions within a grain boundary. The results of these calculations indicate that these interactions are present and provide a basis for understanding the qualitative features of intergranular embrittlement.

Descriptors :   *Nickel, *Embrittlement, *Grain boundaries, *Molecular orbitals, Sulfur, Impurities, Chemical bonds, Cracking(Fracturing), Models, Molecular structure, Clustering

Subject Categories : Inorganic Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE