Patent ID: 6858103

Claim:
A method for optimizing alloy heat treatment by quantitatively predicting thermal growth during alloy heat treatment, the method comprising the steps of: (a) predicting a volume change due to transformations in an each precipitate phase; (b) predicting an equilibrium phase fraction of the each precitate phase; (c) predicting a kinetic growth coefficient of the each precipitate phase; (d) predicting thermal growth in a precipitation-hardened Al —Si—Cu alloy according to a thermal growth model using the volume change due to transformations in the each precipitate phase; the equilibrium phase fraction of the each precipitate phase; and the kinetic growth coefficient of the each precipitate phase, wherein the thermal growth model may be expressed mathematically as: g ⁡ ( t , T ) = ( 1 - γ ) ⁢ ∑ i = 1 n ⁢ δ ⁢ ⁢ V i 3 ⁢ V i ⁢ f i ⁡ ( t , T ) where δ ⁢ ⁢ V i 3 ⁢ V i is volume change due to transformations in precipitate phase i, ƒ i (t,T) is fraction of solute in precipitate phase i as a function of time and temperature, T is temperature, t is time, and γ is fraction of solute lost to eutectic phases; and (e) aging the precipitation-hardened Al—Si—Cu alloy for an aging time (t) and an aging temperature (T) according to the thermal growth model to produce a dimensionally stable precipitation-hardened Al—Si—Cu alloy.