Metal-Matrix Composites of Closed Geometries

Abstract

Procedures are described for fabricating Borsic filament-reinforced aluminum-alloy composites of closed circular geometry. Two circumferentially reinforced shapes are considered: a thickwalled right circular cylinder and a thin-walled conic section. The parts were fabricated by plasma spraying the alloy over hoopwound Borsic filament, and then densifying in ways which avoided damage to the brittle filament. Axial compaction of the cylinder resulted in a fully dense part without degradation of the Borsic. The conic section was densified by the radial thermal expansion of an aluminum die which forced a semiliquid matrix alloy between the filaments. Properties were measured by ultrasonic and mechanical methods.