Fractographic evaluation of crack initiation and growth in Al-CNTs nanocomposite fabricated by induction melting

Abstract

Presence of reinforcement material in the matrix plays a vital role in modifying the fracture topography besides mechanisms of deformation and strengthening of a composite. In the present study, Al-CNT composite was prepared using induction melting technique. The composite was cast into copper mold and cold rolled to 95% reduction in thickness. In as rolled condition, the composite exhibited a simultaneous increase in yield strength (>70%), tensile strength (>50%) and hardness (>40%). The fracture surfaces of the broken tensile specimens were studied using scanning electron microscope. It was observed that the crack initiation was occurred in the matrix followed by void link-ups for its growth. Micro cracks initiation in the matrix played a vital role to sustain the ductility of the material.