Some comments on the "avrami" equation

Abstract

The "Avrami" equation applies rigorously only to a system which does not change volume on transformation and where the developing regions are spheres. The consequences of the impossibility of achieving these conditions in real systems is discussed. It is shown that excessive approximation combined with the use of weight rather than volume fractions can lead to errors in the exponent n of as much as 0.3. It is emphasized that only at very low conversions can meaningful interpretations be made of the exponent. © 1965 The American Institute of Physics.