Measurement of grain size and size distribution in engineering materials

Methods to characterise grain size distribution in engineering materials ar e evaluated, and compared with measurements on two representative materials , an equiaxed aluminium alloy and a heterogeneous nickel alloy. Computer si mulations from a model tetrakaidecahedron structure have also been obtained using a personal computer program to rotate and section the model randomly , generating distribution data on section area and intercept lengths, Compa risons have been made between the model distribution data and intercept dis tribution data from the material microstructures. It is recommended that si ze distributions of area plotted against size (intercept) or normalised siz e provide an effective method for discriminating between different grain si ze distributions, An estimate of urea can be used indirectly by squaring in tercept values rather than making direct measurements of grain areas.