Strength and fracture mechanism of a magnesium alloy for medical applications after equal-channel angular pressing

Abstract

In this paper, we study the strength and fracture mechanism of the cast magnesium alloy Mg-Zn-Ca (1.0 % Zn, 0.2 % Ca) for medical applications after equal-channel angular pressing (ECAP) in comparison with the initial condition (after homogenization annealing). Mechanical tests included tensile and torsion tests of samples with a diameter of 3 mm and impact strength tests of samples with a V-shaped stress raiser. The microrelief of all fractures was studied in a Phenom ProX G6 scanning electron microscope (SEM). The results of tensile testing of the samples showed that the strength of the alloy after ECAP increased by a factor of 1.5 -1.8, and the elongation increased by a factor 2.6. The torsional strength of the alloy increased by a factor 1.1-1.3, and the relative shear of the alloy decreased by factor a 1.3 as compared with the alloy after annealing. In contrast to static loads, the magnesium alloy Mg-Zn-Са after ECAP is poorly resisting one-time impact loads. Analysis of the results of this study allows us to conclude that the magnesium alloy Mg-Zn-Ca after ECAP is more promising for the manufacture of medical products that experience static loads during operation, as compared with the alloy after annealing.

Attaining High Functional Performance in Biodegradable Mg-Alloys: An Overview of Challenges and Prospects for the Mg-Zn-Ca System

“…The influence of heat treatment, metal-forming techniques relying on strain hardening, and various schemes exploiting severe plastic deformation for grain refinement and texture manipulation are described in refs. [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ]. The relationship between the mechanical and corrosion properties and the anisotropy and texture of magnesium alloys are the focus of dedicated publications [ 50 , 51 , 52 ].…”