Heat treatment As for many of the aluminium alloys, Y alloy
age hardens spontaneously at normal temperatures after
solution heat treating. The heat treatment is to heat it to for 6 hours, then to allow it to age naturally for 7–10 days. The
precipitation hardening that takes place during this ageing forms precipitates of both CuAl2 and NiAl3. The times required depend on the grain structure of the alloy. Forged parts have the coarsest eutectic masses and so take the longest times. When cast,
chill casting is favoured over
sand casting as this gives a finer structure that is more amenable to heat treatment. == References ==