Manufacture and mechanical properties of saffil-reinforced aluminium alloys

Composites based upon Al-Cu-Mg-Ag alloys reinforced with Saffil fibre have been manufactured and tested. A good fibre/matrix bond was established duri ng composite processing, as evinced by the match between dynamic modulus me asurements and 'rule of mixtures' calculations. It was also shown that the fibre and preform binder reacted with magnesium and changed the mode of mat rix precipitation, suppressing the Omega phase which characterises heat-tre ated Al-Cu-Mg-Ag alloys in favour of the theta' phase found in binary AI-Cu alloys. The composites exhibited continuous yielding from the start of a t ensile test owing to the way that fibre orientation influenced localised re sidual stress and yielding of the matrix. Proof stress was enhanced by heat treatment although tensile strength appeared to be deleteriously affected by the presence of reacted preform binder. (C) 1999 Elsevier Science Ltd. A ll rights reserved.