THE USE OF FOIL METALLURGY PROCESSING TO ACHIEVE ULTRAFINE GRAINED MG-9LI LAMINATES AND MG-9LI-5B4C PARTICULATE COMPOSITES

A foil metallurgy processing technique has been developed to prepare fine-grained laminates based on a two-phase Mg-9Li alloy and fine-grained particulate composites based on hard B4C powders embedded in the two-phase Mg-9Li alloy. The processing steps involve principally cold-rolling and low-temperature recovery processing for preparation of foils, and low-temperature press-bonding for preparation of laminates and composites. In this manner, contamination of the highly reactive alloy is minimized. Good tensile strength and ductility were achieved at room temperature with specific stiffness values of about 3.1 × 106 m3. Both the fine-grained laminates and the particulate composite are superplastic at 200 ° C, exhibiting a strain-rate-sensitivity exponent, m, of 0.5. © 1990 Chapman and Hall Ltd.