This article presents the results of modelling of the mechanical behaviour of biocompatible Zr-Nb and Ti-Nb alloys in the range of strain rates from 10(-3) to 10(3) s(-1) at temperatures from 297 K to 1273 K. Modification of the micro-dynamical model was proposed for the description of Zr-1Nb ultrafine grained and coarse grained alloys. It was shown that the phase transition HCP -amp;gt; BCC alloy Zr-Nb at elevated temperatures leads to a sharp changing in the resistance to plastic flow and kinetics of growth of damage. The results can be used for engineering analysis of designed constructive elements of technical and biomedical applications.