LATTICE-PARAMETER OF THE ZR-NB BCC PHASE - NEUTRON-SCATTERING STUDY AND ASSESSMENT OF EXPERIMENTAL-DATA

The composition dependence of the lattice parameter (a(beta)) for the bcc (beta) phase in the Zr-Nb system at room temperature has been esta blished by combining new experiments with an assessment of previously published data on bcc Nb, bcc Zr and their alloys. The experimental pa rt of the work comprises neutron scattering measurements on alloys wit h Nb contents between 13 and 48 at.% Nb, quenched from high temperatur es. A detailed comparison is performed with previous X-ray measurement s. The present results are also used in testing the applicability of V egard's law in the Zr-Nb system, and in determining the probable a(bet a) value for Zr, which cannot be measured at room temperature.