Characterization of fracture and debonding of Si particles in AlSi alloys

The Al/Si interface debonding, fracture of Si particles and plastic deformation in Al matrix have been studied mainly from morphology point of view using finite element method. An interface debonding model and a fracture model of the particles in the matrix were proposed. Both models were experimentally validated. It has been shown that higher sphericity of Si particles and harder Al matrix are favorable to resistance to interface debonding, particle fracture and matrix plastic deformation. A detailed surface damage map has been composed to display the three surface failure mechanisms corresponding to various particle dimensions/shapes and matrix properties.

Research highlights▶ Particle morphology is one of the main factor determining the wear properties of MMC. ▶ Particles with shape closer to sphere decrease the fracture and debonding in the MMC. ▶ Harder matrixes in the MMC reduce the risk of severe plastic deformation and particle debonding.