Accession Number : AD0635694

Title :   SINGLE CRYSTAL ALUMINA BY THE STRAIN-ANNEAL TECHNIQUE.

Descriptive Note : Summary rept. 25 Mar 65-24 Mar 66.

Corporate Author : AVCO CORP WILMINGTON MASS SPACE SYSTEMS DIV

Personal Author(s) : Sellers, D. J. , ; Rhodes,W. H. ; Vasilos,T.

Report Date : 24 MAR 1966

Pagination or Media Count : 16

Abstract : Single crystals of Al2O3 were grown by the strain-anneal technique to a maximum size of 7 cubic centimeters. All the crystals contained a small percentage of porosity, and cracking at the boundary of the polycrystalline region also appeared to be an experimental difficulty. The critical strain for producing few growth nuclei, and thus enhanced single crystal growth, is thought to be approximately 5%. Evidence was obtained for the removal of porosity during grain growth accompanying primary recrystallization. (Author)

Descriptors :   (*REFRACTORY MATERIALS, SINGLE CRYSTALS), (*ALUMINUM COMPOUNDS, OXIDES), (*CRYSTAL GROWTH, REFRACTORY MATERIALS), POROSITY, MICROSTRUCTURE, STRAIN(MECHANICS), ANNEALING, RECRYSTALLIZATION, DEFECTS(MATERIALS)

Subject Categories : Ceramics, Refractories and Glass
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE