Accession Number : AD0486701

Title :   A STUDY OF THE PHYSICAL BASIS OF MECHANICAL PROPERTIES OF CERAMICS.

Descriptive Note : Final rept. 15 Mar 65-15 Feb 66,

Corporate Author : MIDWEST RESEARCH INST KANSAS CITY MO

Personal Author(s) : Gross, Gordon E. ; Gutshall, Paul L.

Report Date : MAY 1966

Pagination or Media Count : 48

Abstract : A study of the physical basis for the mechanical properties of ceramics is reviewed. Brittle fracture studies in alumina are presented, along with a test method developed for studying the fracture resistance of ceramics. It has been shown that the fracture resistance of polycrystalline ceramics increases with grain size, whereas the modulus of rupture for the same specimens decreased with increasing grain size. The conclusion reached is that an optimum structural ceramic unit should combine large grains in its interior (for high fracture resistance) with a fine grain surface layer to minimize the depth of initial surface microcracks (for high modulus of rupture). Further evidence of a dislocation fracture mechanism in the alkali halides is also presented. (Author)

Descriptors :   *OXIDES), (*CERAMIC MATERIALS, TENSILE PROPERTIES), (*ALUMINUM COMPOUNDS, FRACTURE(MECHANICS), TEST METHODS, TEMPERATURE, CRYSTAL DEFECTS, DEFORMATION, GRAIN SIZE, POROSITY, INTERNAL FRICTION, PHOTOELASTICITY, HALIDES, ALKALI METAL COMPOUNDS, MODULUS OF ELASTICITY, GERMANIUM, RUPTURE, MATHEMATICAL PREDICTION, BRITTLENESS, DUCTILITY, RADIATION EFFECTS, LIGHT.

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE