ABSTRACT
The Al3Zr precipitation behaviours of as-quenched and heat-treated samples of a melt-spun Al-0.2Cu-l.2Mg-0.5Zr alloy have been studied by TEM. The results show that metastable f.c.c. Al3Zr can be formed during solidification, and that initial Al3Zr precipitation occurred in the subgrain boundaries. Fine spherical LI 2 Al3Zr particles precipitated within the grains after heat treatment at 450°C for 16 hours, and they were stable in this form even after holding at 450°C for 100 hours. The stable tetragonal DO23 Al3Zr phase was found after heat treatment at 500°C for 100 hours.
