Effects of Y additions on the precipitation and recrystallization of Al–Zr alloys

• Additions of Y obviously accelerate the precipitation kinetics of Al3Zr in Al–Zr–Y.
• High density and small radius of Al3(Zr,Y) (L12) are obtained in Al–Zr–Y.
• The coarsening rate of Al3(Zr,Y) is slower than that of Al3Zr at 500 °C.
• Additions of Y increase the recrystallization temperature of Al–Zr alloys by 50 °C.

The effects of Y on the precipitation evolution and recrystallization of Al–Zr alloys were investigated. The results show that the addition of Y obviously accelerates the precipitation kinetics of Al3Zr with L12 structure in Al–Zr–Y alloys. The number density of Al3(Zr,Y) precipitates is nearly one order of magnitude larger than that of Al3Zr. Smaller Al3(Zr,Y) precipitates near grain boundaries keep relatively high number density in Al–0.30Zr–0.08Y, whereas Al3Zr precipitates show decreased number density and larger radius towards the grain boundaries in Al–0.30Zr. Precipitate free regions adjacent to grain boundaries in Al–0.30Zr–0.08Y are much narrower than that in Al–0.30Zr. The Al3(Zr,Y) precipitates exhibit slower coarsening kinetics at 500 °C as compared with Al3Zr. The recrystallization temperature of Al–Zr–Y alloys is about 50 °C higher than that of Al–Zr alloys.