Fabrication of aluminium matrix composites reinforced by submicrometre and nanosize Al 2 O 3 via accumulative roll bonding

Aluminium matrix composites reinforced with submicrometre and nanosize Al₂O₃ particles were successfully manufactured in the form of sheets through eight cycles of accumulative roll bonding process. The mechanical properties of the produced composite are compared with accumulative roll bonded commercially pure aluminium. It is shown that only 1 vol.- of submicrometre or nanosize alumina particles as reinforcement in the structure can significantly improve the yield and ultimate tensile strengths. Scanning electron microscopy revealed that particles have a random and uniform distribution in the matrix especially in the less volume fraction of alumina particles, and strong mechanical bonding occurs at the interface of the particle matrix. According to the results of the tensile tests, it is observed that with less alumina content, the composite reinforced by nanosize particles has higher strength than that by submicrometre size particles. However, more reinforcement up to 3 vol.- of submicrometre particles, as a result of including fewer microstructural defects, leads to better mechanical properties in comparison to the nanoparticle composite.