Effect of the Particle Size on the Deformation and Fracture Behavior of Al/4vol.%Al2O3 Composite Produced by Accumulative Roll Bonding (ARB)

In this study, Al/Al2O3 composites with two different particle sizes of 1 µm and 0.3 µm were produced via accumulative roll bonding (ARB). The microstructure evolution, mechanical properties and fracture behavior of the composites were investigated. Results show that higher ARB cycles are required to achieve a uniform distribution of particles in the composite with 0.3 µm particle size. During ARB, dense cluster of the particles broke up and a uniform distribution of particles was achieved after eight ARB cycles. The tensile strength of the composite with 1 µm and 0.3 µm particle size enhanced by increasing the number of ARB cycles, reached to about 170 MPa and 175 MPa, respectively, in comparison to that of the annealed Al (about 47 MPa). The finer particles caused a higher tensile strength due to the decrease in the distance between the particles at a given volume fraction. The fracture surface of both composites revealed ductile type fracture characterized by dimples. The dimples in the composite with particle size of 1 μm were larger and deeper.