Damage behavior and mechanism of SiCp/Al composites under biaxial tension

The deformation behavior and damage mechanism of 17 vol% SiCp/Al composites under biaxial loading were studied by biaxial tension and nano-indentation tests. The results showed that in the process of biaxial tension, the composite in rolling normal direction has underwent less severe damage compared to that in the two tensile directions. However, interfacial debonding, particle shedding and microcrack propagation are accompanied in all three directions. The crack size becomes larger as the cracks gradually propagate on the surface of the material, leading to the failure of the composite. The micromechanical properties of the composite show a trend from a slow increase to a sharp increase. In addition, the distribution characteristics of stress, equivalent plastic strain and stress triaxiality of SiCp/Al composites under biaxial tensile stress are simulated by finite element method. The results showed that the stress and strain of composites increase rapidly along the diagonal direction. In the process of deformation, the stress triaxiality increases gradually, which makes the microcracks propagate easily, so the fracture surface of the composite presents a large number of dimples.