Accession Number : ADA308569

Title :   Transitions and Defects in Crystals.

Descriptive Note : Final rept. 16 Dec 91-15 Dec 95,

Corporate Author : MINNESOTA UNIV MINNEAPOLIS OFFICE OF RESEARCH AND TECHNOLOGY TRANSFER ADMINIS TRATION

Personal Author(s) : Luskin, Mitchell ; James, Richard

PDF Url : ADA308569

Report Date : 06 MAY 1996

Pagination or Media Count : 9

Abstract : The primary objective of this research has been to give strategies for improving shape memory and magnetostrictive materials based on reliable mathematical and computational models. Our theoretical research has led to the prediction of a new type of material, that combines the shape memory and magnetostrictive effects. Also, relying on experimental data obtained in our laboratory, we have been led to model the kinetics and hysteresis in a Cu-Al-Ni shape memory alloy by a new 'wiggly energy' concept: many little wiggles are superimposed on the energy to reflect small scale microstructural changes. We have developed has rigorous theory for the analysis of the approximation of microstructure which will allow the development of efficient and reliable numerical methods for microstructure. Our research group has also developed methods and codes which have been used to compute complex equilibrium and dynamical microstructures.

Descriptors :   *MICROSTRUCTURE, *ALUMINUM ALLOYS, *COPPER ALLOYS, *MAGNETOSTRICTION, STRESS STRAIN RELATIONS, MATHEMATICAL MODELS, PHASE TRANSFORMATIONS, CRYSTAL LATTICES, FINITE ELEMENT ANALYSIS, THIN FILMS, INDIUM ALLOYS, PHASE STUDIES, AUSTENITE, DEFECTS(MATERIALS), APPROXIMATION(MATHEMATICS), NICKEL ALLOYS, NUMERICAL METHODS AND PROCEDURES, HYSTERESIS, FERROMAGNETIC MATERIALS, MOLECULAR ENERGY LEVELS, MARTENSITE, THALLIUM ALLOYS.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE