KINETICS OF HARDNESS CHANGES DURING AGE-HARDENING OF SILUMIN

Simple phenomenological description of age-hardening kinetics of supersaturated solid solution is presented using the sum of exponential functions with negative arguments containing rate constants, for whose temperature dependence the Arrhenius equation is used. The number of exponentials in the sum is discussed considering sufficiently accurate description as well as the number of distinguishable processes occurred during hardening. Also the limits of this approach are presented. Hardness changes of silumin during age-hardening are used for demonstration of this procedure.