Structure Evolution in Rapidly Solidified Al-Fe-V-Si Alloys of Different Components Ratio

摘要

New aluminium alloys designed for application at elevated operating temperatures are of special interest lately. The presence of transitional elements as main components in the alloy enables a multiphase structure sensitive to thermal treatment to appear. An as-cast structure with high volume ratio of fine inter-metallic compounds could be produced by solidification of the molten alloy at high cooling rates. This could be achieved by rapid solidification techniques, e.g. Planar Flow Casting, leading to an Al-solid solution supersaturated with fine primary phases imbedded. The temperature stability of such a microstructure depends on both the low equilibrium solubility of components in Al-matrix and their low diffusivity up to 700 K. Studies of the quaternary alloy of system Al-Fe-V-Si are discussed. Al-8.5Fe-1.3V-1.7Si wt% is used as a base alloy. The effect of content change is investigated, especially the change of Si-concentration from 1.7 to 9 wt%. The as-cast structure and its phase evolution during annealing at the studied temperature is observed.