The Portevin-Le Chatelier Effect in Corrosion Behavior of the Mg-Zn-Sr Alloy

Abstract

The as-solutionized Mg-4Zn alloys, one candidate material for biological implantation, are featured with the Portevin-Le Chatelier effect during the tensile testing with strain rate of 6.67 × 10−7 s−1, which leads to the higher corrosion rate and the acceleration of stress corrosion cracking. With the increase of the strain, new slip bands are generated and the proliferation of dislocations is very rapid in slip bands. The microgalvanic corrosion occurs between the slip bands (anode) and the low dislocation density region (cathode). The 0.1 wt% Sr addition can reduce the impact of the Portevin-Le Chatelier effect on as-solutionized Mg-4Zn alloy, resulting from the inhibition of twin, the better grain coordination deformation ability, and the lower density of geometrically necessary dislocations.