Tensile behavior and dynamic failure of aluminum 6092/B4C composites

Aluminum 6092/(B4C)p metal matrix composites fabricated by two different powder consolidation routes, extrusion (EXTR) and sintering/hot isostatic-pressing (HIP), were made and tested over a wide range of strain rates (10−4 to (3 × 102) s−1) under tension. A tension-compression asymmetry of constitutive behavior is observed: the flow strength and ductility of these composites under tension are lower than those under compression. Such asymmetry is reinforcement volume fraction dependent, and the extent of asymmetry is larger for HIP composites. Fractographic observations show different interfacial bonding characteristics (good bonding for the EXTR composites and relatively weak bonding for the HIP composites), indicating a strong effect of interfacial debonding on the constitutive and failure behavior of these composites. TEM observations reveal a weak amorphous layer composed mainly of aluminum, magnesium and carbon along Al/B4C interface in the HIP composites, which is consistent with the experimental observations.