Creep, Strength, Expansion, and Elastic Moduli of Sintered BeO As a Function of Grain Size, Porosity, and Grain Orientation

Physical properties are presented for extruded and sintered BeO from 25° to 1400° C as a function of porosity (0 to 15%), grain size (5 to 100μ), and grain orientation (random to 80% preferred). The elastic constants and linear thermal expansion are sensitive to the degree of preferred grain orientation. Measurements on polycrystalline specimens permitted calculation of the anisotropy in single crystals of BeO for these properties. Modulus of rupture data are treated in terms of the Knudsen equation, and compressive creep data have been used to estimate the diffusion coefficient controlling strain rate at 1200°C.