Influence of interface properties on mechanical behaviour of particle reinforced metal matrix composite

AbstractThe mechanical properties and fracture mechanism of an aluminium alloy A356–20 vol.-%SiCP cast composite are presented and related to the treatments experienced during the casting procedure and to the aging evolution of the alloy. The treatments were aimed at investigating possible changes of the composite damage mechanism produced by modifying the properties of the matrix/reinforcement interface region. An A356–5%SiCP composite was also characterised to support the study on the conventional composite and to carry out calculations, based on the ductile fracture mechanism, concerning the interface stress acting in the material at fracture. Notwithstanding the approximation of the calculation method, the results obtained quantitatively confirmed the fractographic observations. It is suggested that there was a progressive weakening or embrittlement of the interfaces either when liquid phase reactions occurred or when the matrix alloy was overaged.MST/1864