Grain boundary pinning by Al 6Mn precipitates in an Al–1wt%Mn alloy

Abstract

The grain boundary area per unit of volume, S V, and the interface area per unit of volume of Al 6Mn precipitates, S VP, were measured in a high purity Al–1wt%Mn alloy for an annealing time of 3600 s at temperatures ranging from 500 to 620 °C. The experimental results show very good agreement with the expression proposed by Rios [Acta Metall. 35 (1987) 2805]: S VL=3 S VP where S VL is the limiting grain boundary area per unit of volume. This expression is easier to verify experimentally than its equivalent form: R L= r/6 f, where r is the particle radius, f is the volume fraction of the particles and R L is the limiting grain radius.