Accession Number : ADA272088

Title :   Microstructure Evolution in the Presence of Constraints and Implications on the Properties of Mg - Li and Nb - Al Constraints.

Descriptive Note : Final rept. 1 Jun 90-31 May 93,

Corporate Author : CINCINNATI UNIV OH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Sekhar, J. A. ; Fabietti, L. ; Carr, D. ; Cantrell, L. ; Dey, N.

Report Date : 31 MAY 1993

Pagination or Media Count : 358

Abstract : The objective of the research was to gain fundamental knowledge of solidification microstructure evolution in the presence of constraints and to apply this knowledge to relevant intermetallic composite designs. The work involved numerical modeling, transparent material solidification and the solidification of Mg-Li and Nb-Al composites. All work was completed and several novel findings are described in this report. This report is the first comprehensive document dealing with morphological evolution of solidification microstructure when constrained by diffusional barriers with different types of interface. First time report of non-directional dendrites and S/L interface strain energies leading to defect formation are disclosed. Development strategies and microstructure maps for particulate and fiber composites are reported.

Descriptors :   *MICROSTRUCTURE, *PARTICLES, *MAGNESIUM, *LITHIUM, *NIOBIUM, *ALUMINUM, *COMPOSITE MATERIALS, *INTERMETALLIC COMPOUNDS, BARRIERS, DIRECTIONAL, DOCUMENTS, FIBERS, GAIN, INTERFACES, MAPS, MATERIALS, PARTICULATES, SOLIDIFICATION, STRATEGY, TIME, DIFFUSION, DEFECT ANALYSIS, FIBERS, NITRILES, ACETONES, ALLOYS, DENDRITIC STRUCTURE, WETTING.

Subject Categories : Laminates and Composite Materials
      Inorganic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE