Abstract
Al-Cu alloys of compositions near eutectic point [hypoeutectic (Al-19Cu), eutectic (Al-33Cu) and hypereutectic (Al-35.5Cu) and (Al-36Cu)] were chemically modified by adding 0.6 wt-%Al-Ti5-B1 master alloy. In addition, the specimens of unmodified and chemically modified eutectic alloy were heat treated at 500 degree C for different holding times (4, 24, 48 and 72 h for the unmodified and 4 and 29 h for the modified ones) followed by water quenching. The structure of chemically treated alloy was changed from large dendrites to fine rosette shaped alpha -Al grains inside fine eutectic matrix. For these alloys, the liquid-solid transformation temperature was shifted to a higher value. The addition of Al-Ti5-B1 master alloy to the eutectic (Al-33Cu) alloy transforms it into hypoeutectic one of fine lamellar eutectic structure. The chemically treated hypereutectic alloy (Al-35%5Cu) was changed into full eutectic alloy.