The amount of porosity has been increased with the
decrease of the reinforced particle size of Al2O3/SiC
particle reinforced composite. Because of the decreasing
particle size and increasing number of particles in a unit
volume, the larger surface area has occurred. Therefore,
this feature increases the surface energy of particles.
That is why the amount of porosity increases due to the
decreasing particle size. Shuangjie and Renjie [24] have
presented similar results.
Furthermore, during the production process of the
composite materials, the porosities, which have occurred
with particle reinforcement, resulted in lower density
compared to theory.
The results obtained from the experiments showed
that when the solidification-cooling rate decreased, the
crystalline grain size of the matrix alloy and the eutectic
silicon phase increased gradually, but the bending
strength and hardness decreased. Fracture surfaces of
the AMCs broken and cleaved Al2O3/SiC particles were
observed on the fracture surfaces of the composites