On the Determination of the Size Distribution Functions of Spherical Precipitations in Al–Zn Alloys by Neutron Small-angle Scattering

The size distribution of approximately spherical incoherent precipitations of Zn in AlZn-alloys is calculated and experimentally tested by means of neutron small angle scattering (NSAS) at a double-crystal diffractometer (DCD). The scattering curves can be approximated by a Gaussian function, so that the size distribution is directly calculated for the experimentical scattering curves under application of a particular LAPLACE-transformation. The size distributions of the α′_m-phase of AlZn(16)-samples of different averaged radii of precipitations are calculated by means of FWHM which are determined by the fitting procedure of a computer programme and compared with TEM micrographs.