Al2O3 Whiskers Research Articles

Kinetics of Growth of Al2O3 Whiskers

The kinetics of the growth of Al2O3 whiskers by the reaction of Al with a trace amount of H2O in an H2 atmosphere were studied. The activation energy in the region of constant growth rate was ∼77 kcal mol−1. This activation energy value, in the light of thermodynamic calculations and other theoretical considerations, suggests that the rate‐determining step in the growth of these whiskers is the dissociation of H2O molecules on the surface of Al2O3.

Normal modulus of elasticity of ceramic whiskers

1. A technique has been developed for determining the normal modulus of elasticity of whiskers from the rate of propagation of longitudinal ultrasonic vibrations. 2. The normal moduli of elasticity of aluminum oxide, silicon carbide, aluminum nitride, and molybdenum trioxide whiskers were measured. 3. It is shown that the normal moduli of elasticity of Al2O3 and SiC whiskers are virtually identical with those of the corresponding massive single crystals, when measured in the same crystallographic directions.