Characterisation of precipitates formed in high-pressure torsion treated Mg-3.4at.%Zn alloy

Abstract

Microstructural analysis of a Mg-Zn alloy deformed at room temperature by highpressure torsion (HPT) indicates that fine-scale precipitation occurs even without postdeformation heat treatment. Small-angle X-ray scattering detects precipitates with radii between 2.5-20 nm after one rotation, with little increase in particle size or volume fraction after 20 rotations. High resolution electron micrographs identify grain boundary precipitates of monoclinic Mg 4 Zn 7 phase after three rotations and MgZn 2 after 20 rotations.