Accession Number : ADA320410

Title :   Quantum Mechanical Approach to Understanding Micro-Structural and Mechanical Properties of Intermetallics.

Descriptive Note : Final rept. 1 Jan 92-31 Jan 95,

Corporate Author : NORTHWESTERN UNIV EVANSTON IL

Personal Author(s) : Freeman, Arthur J.

PDF Url : ADA320410

Report Date : 28 FEB 1995

Pagination or Media Count : 20

Abstract : The primary goal of the proposed research was to study and develop alloying concepts for understanding intermetallic alloys as derived from a first principles quantum mechanical approach. Thus, a major part of our effort was to study and determine ductilizing effects of alloying elements in several intermetallic compounds and to work closely with experimental efforts to evaluate the applicability of the theoretical approach to alloy design. Specifically, highly precise all-electron quantum mechanical electronic structure methods were applied to the study of a number of materials problems in order to obtain from first principles information of relevance to alloy stability on the design of structural materials. Using our recently developed state-of-the-art all-electron self-consistent total energy methods which gives precise solutions of the local density equations, fundamental information was sought about the structural and electronic properties of these alloys in order to predict stable and metastable phases and how alloying effects bonding, crystal ordering and crystal symmetry. The first principles approach used here addresses questions of a metallurgical nature, such as phase stability, crystal structure, equilibrium lattice constants and mechanical properties including the effect of atomic relaxation.

Descriptors :   *QUANTUM THEORY, *INTERMETALLIC COMPOUNDS, MECHANICAL PROPERTIES, CRYSTAL STRUCTURE, CHEMICAL BONDS, ELECTRONIC STATES, LATTICE DYNAMICS, METASTABLE STATE.

Subject Categories : Metallurgy and Metallography
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE