Fracture behaviour of SiCp/Al composites with network architecture

It is found that, for discontinuous metal matrix composites (MMCs) with an inhomogeneous network reinforcement distribution, a thin network layer and large alloy cells are favorable for the toughness. The network layers contribute to the high modulus and strength, while large alloy cells work in deflecting crack propagation and thus enhancing the toughness. Furthermore, mutually coordinated and restricted deformation behaviors of alloy cells may create a three-dimensional tensile stress state, which induces the anomalous brittle fracture of intrinsically ductile aluminum matrix in some alloy cells. These phenomena have weakened the matrix alloy plastic deformation capacity, constrained the crack propagation and improved the toughness of network composites.