Accession Number : ADA311191

Title :   Investigation of High-Temperature Eutectic-Based Microcomposites.

Descriptive Note : Final rept. Mar 93-Mar 96,

Corporate Author : GENERAL ELECTRIC CORPORATE RESEARCH AND DEVELOPMENT SCHENECTADY NY

Personal Author(s) : Bewlay, B. P. ; Lipsitt, H. A. ; Jackson, M. R. ; Sutliff, J. A.

PDF Url : ADA311191

Report Date : 29 APR 1996

Pagination or Media Count : 57

Abstract : The present report describes an investigation of high temperature directionally solidified eutectic-based microcomposites. The principal topics of the present report are the results of the investigations of the third year of this project. Details of earlier investigations have been described in the first and second year annual reports, and published in the open literature. This report describes the results in four areas. First, an advanced niobium-silicide based composite which shows an attractive balance of high and low temperature properties, such as fracture toughness, tensile strength, creep performance and oxidation behavior are described. The density-reduced stress rupture behavior of this composite showed an improvement over current generation advanced Ni-based superalloys. Second, recent studies of toughening mechanisms in composites generated from ternary Nb-Ti-Si alloys are described. Fracture toughness values of >20 MPa square root of m have been measured in as-DS composites. Third, the microtexture of the silicide and metallic phases in a ternary Nb-Ti-Si alloy composite have been investigated using the electron back scattering pattern technique for electron diffraction in the SEM. Microtexture measurements were performed to examine the relationship between texture and mechanical properties. Finally, the recent data relating to the ternary Nb-Ti-Si phase diagram is described.

Descriptors :   *COMPOSITE MATERIALS, *HIGH TEMPERATURE, *EUTECTIC COMPOSITES, STRESSES, THERMAL PROPERTIES, METALS, DENSITY, LOW TEMPERATURE, MECHANICAL PROPERTIES, TENSILE STRENGTH, TOUGHNESS, SOLIDS, RUPTURE, FRACTURE(MECHANICS), PHASE, OXIDATION, SILICON, CREEP, NIOBIUM, NICKEL, TITANIUM, ELECTRON DIFFRACTION, TEXTURE, SILICIDES, SUPERALLOYS.

Subject Categories : Properties of Metals and Alloys
      Inorganic Chemistry
      Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE