The influence of the distribution of alumina continuous fibre on the age hardening behaviour in Al-Si-Cu and Al-Si-Cu-Mg Alloys are reported. Artificial ageing at 433 or 473 K was applied to a series of specimen prepared via solution heat treatment and quenching in ice water. A significant acceleration in the age hardening sequence and an increase in the age hardening response (δHV = HVMAX - HVST) were found in fibre-reinforced Al-Si-Cu alloy. TEM observation revealed that GP zone, θ' and θ phase precipitate on the dislocation around continuous fibres. The acceleration of age hardening sequence is attributed mainly to the precipitation site of these dominant phases. Therefore, λ' phase homogeneously precipitates independent of dislocations in the matrix phase of fibre-reinforced Al-Si-Cu-Mg alloy. The prior formation of MgAl2O4 at the fibre/matrix interface decreases both Mg concentration in the matrix alloy and the age hardening response.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys