Accession Number : AD0728050

Title :   Diffusional Prestressing of Ceramics.

Descriptive Note : Summary rept. 15 Oct 69-14 Oct 70,

Corporate Author : SOUTHERN RESEARCH INST BIRMINGHAM ALA

Personal Author(s) : Bickelhaupt,Roy E.

Report Date : DEC 1970

Pagination or Media Count : 93

Abstract : The report describes the effect of diffusional prestressing on the mechanical properties of magnesium oxide single crystals. Flexural specimens were compressively prestressed by diffusionally developing an NiO-MgO solid solution zone at the surfaces. The compressive prestress occurred due to the favorable difference in coefficient of expansion between the host crystal and the solid solution. Using experimentally determined and known material characteristics, the anticipated quantitative effect of prestressing was calculated. Flexural specimens were mechanically and microscopically characterized. For comparative purposes, specimens were prepared by thermally annealing and by diffusionally annealing crystals that originally either contained grown-in dislocations or fresh dislocations. Half of the specimens were tested after the reintroduction of fresh dislocations. (Author)

Descriptors :   (*MAGNESIUM OXIDES, STRESSES), DIFFUSION, SINGLE CRYSTALS, FLEXURAL STRENGTH, RECRYSTALLIZATION

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE