Volume Fraction Of Aluminum Research Articles

A quantitative analysis of the thermoelectric power measurements on composite Al-Ge films

Thermoelectric power (Seebeck coefficient) measurements at room temperature have been made on composite Al-Ge films for aluminum volume fractions ranging from 20% to 100%, the metal-insulator transition being at about 55%. These measurements were motivated to test theoretical predictions recently suggested by Bergman and Levy. The electrical conductivity, substituted in their equation, was obtained both by direct measurements and an effective media equation while the thermal conductivity was obtained from two different effective media equations. The agreement between the theoretical and experimental results support the correctness both of their theory and the effective media equations used.

Preparation of Alumina/Aluminum Composites by Oxidation of Aluminum

Al2O3/Al composites containing a small amount of tin were prepared by the oxidation of the powder compacts of aluminum and tin coated with MgO powder at 1200° and 1250°C. The composite phase grew mainly on the MgO-coated face of the compacts. The thickness of the composite phase varied with the amounts of coated MgO and tin. The effects of the amount and particle size of the MgO powder on the thickness of the composite phase were explained on the basis of the concentration of magnesium produced by the reaction between MgO and molten aluminum. The volume fraction of aluminum in the composite phase decreased with increasing amount of MgO and increased by the addition of tin. The volume fraction of pore in the composite was less than 3vol% under usual conditions.