STRUCTURE TRANSFORMATION OF THE ZN-LI-MG ALLOY DURING HPT

Abstract

This paper presents the results of a study of the effect of severe plastic deformation by torsion (HPT) on the transformation of the structure and mechanical properties of the bioresorbable zinc alloy Zn-0.8%Li-0.1%Mg. The strain rate during HPT, as well as the number of revolutions, were analyzed. A deformation regime is proposed that ensures the formation of a homogeneous structural-phase state. A mode has been established in which grain refinement by HPT leads to an increase in the strength characteristics of the Zn-0.8%Li-0.1%Mg alloy due to the formation of an ultrafine-grained structure (UFG). The UFG structure formed by HPT provides an increase in microhardness from 98 HV to 185 HV. The tensile strength of the samples after HPT at a strain rate of 10–3 s–1 was 595 MPa, the elongation to failure was 47%, which is several times higher than the required parameters for medical applications.