FRACTURE CHARACTERISTICS OF METAL/INTERMETALLIC LAMINAR COMPOSITES PRODUCED BY REACTION SINTERING AND HOT-PRESSING

Metal/intermetallic layered composites were formed by process recently developed in which a self-propagating, high-temperature synthesis reaction was initiated at the interface between dissimilar metal foils. After the reaction, one of the metal foils was entirely consumed, resulting in a metal/intemetallic laminar composite. This study details the tensile fracture characteristics of these unique composites. Fracture mechanism and failure energy were controlled by varying the intermetallic-to-metal volume ratio. Failure initiated with the formation of cracks in the intermetallic layer. For high intermetallic-to-metal ratios, the intermetallic crack release energy was too great to prevent cracks from propagating through the metal layer and propagating the crack into the adjacent intermetallic layers, leading to a fast, low energy fracture. For lower intermetallic-to-metal ratios, the metal layers adsorbed the intermetallic crack release energy and blunted the propagating crack. Final failure resulted by ductile fracture of the metal layer after extensive intermetallic cracking.