Abstract
A statistical evaluation by means of Weibull statistics was carried out on the tensile strength data of a short mullite fibre reinforced aluminium alloy composite, which was prepared by squeeze casting. The results show that the material has a high and reliable tensile strength. The area fractions of the fibres on the cut surface and on the fracture surface of specimens have been statistically analysed. The fibre distribution shows heterogeneity in the microsturcture. On the cut surface the average area fraction of fibres which make large angles with the normal of the cut surface (denoted as A fl ) is slightly less than that of those fibres which make a small angle with the normal of the cut surface (denoted as A fs ). However, on the fracture surface of the composite, A fl is much bigger than A fs , and the lower the tensile strength of the specimen, the bigger is A fl on the fracture surface. Debonding of the interface between the large angle fibres and the matrix is an important cause of failure of the composite, and the non-uniform distribution of the large angle fibres is one of the main causes of the large scatter in the data.