Influence of microstructure of fibre/matrix interface on mechanical properties of Al/SiC composites

Abstract

The relationship between microstructure and mechanical properties of composites of squeeze cast Al–Cu and Al–Cu–Mg reinforced with 25 vol.-%SiC whiskers was investigated. Tensile test results were compared with values calculated using a modified rule of mixtures (ROM). The results were found to be in good agreement for the Al–Cu matrix composite, whereas a relatively large discrepancy was observed for the Al–Cu–Mg matrix composite. It was concluded from microstructural observations that this difference resulted from a reduction of the whisker strength due to more pronounced decoration of the interfaces by oxides and spinels. For the Al–Cu–Mg composite, the effect of interfacial phases on the composite strength must betaken into account when the modified ROM is applied.

MST/1242