Accession Number : ADA190407

Title :   Investigation and Synthesis of High Temperature and Increased Stiffness RSP Aluminum Alloys.

Descriptive Note : Annual rept. 1 Oct 86-30 Sep 87,

Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF MATERIALS SCIENCE AND ENGINEERING

Personal Author(s) : Fine, Morris E ; Weertman, Julia R

PDF Url : ADA190407

Report Date : Sep 1987

Pagination or Media Count : 21

Abstract : This objective of this research is to investigate two promising systems as th basis for high temperature aluminum alloys useful to 425 C (800 F). The first is metal matrix composite consisting of an aluminum magnesium alloy matrix reinforced by spinel (magnesium aluminate) particulate. The second system is tri aluminum (zirconium, vanadium) dispersed in aluminum matrix. Here the lattice parameter matches that of the matrix. Research on dilute alloys has shown a low coarsening rate for this intermetallic at 425 C. Study of more concentrated alloys is underway. A mechanical alloying liquid metal infiltration procedure for preparing specimens of the aluminum alloy matrix spinel composite has been worked out and specimens with 4 vol% spinel have been prepared. Also, 4 vol.% alumina composite samples were prepared for comparison. Spinel particles were within the aluminum alloys grains in contrast to the alumina which was at grain boundaries. The spinel composite had much better creep resistance at 410 C. Extrusions containing 5 vol.% tri-aluminum (0.75 vanadium, 0.25 zirconium) were prepared for this research by Lockheed-Palo Alto from rapidly solidified foil. The measured creep rate at 425 C is much lower than in the current aluminum-iron-cerium alloy. An aluminum vanadium intermetallic compounds, however, forms at grain boundaries leading to a precipitate free zone which grows slowly at 425 C. Keywords: Aluminum, High temperature alloys, Aluminum-zirconium-vanadium, Aluminum spinel.

Descriptors :   *METAL MATRIX COMPOSITES, ALUMINUM COMPOUNDS, ALUMINUM OXIDES, CERIUM ALLOYS, CREEP STRENGTH, EXTRUSION, GRAIN BOUNDARIES, HEAT RESISTANT ALLOYS, INTERMETALLIC COMPOUNDS, IRON ALLOYS, LIQUID METALS, MAGNESIUM ALLOYS, MAGNESIUM COMPOUNDS, MECHANICAL PROPERTIES, PARTICLES, PRECIPITATES, SPINEL, STIFFNESS, VANADIUM COMPOUNDS, ZIRCONIUM, DUCTILITY, CRYSTAL STRUCTURE, MICROPHOTOGRAPHY

Subject Categories : Properties of Metals and Alloys
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE