Mikrostruktura a korozní vlastnosti slitin na bázi Mg-Ca-Zn-Mn

Abstract

This diploma thesis deals with the issue of new types of magnesium alloys based on Mg-Ca-Zn-Mn. The requirement for magnesium alloys is that they are not only biocompatible, non-toxic and have suitable mechanical properties, but also that they are able to biodegrade over time in the biological environment. With an implant made of such a magnesium alloy, it is possible to prevent reoperation, in which the implant remains in the human body until the bone has completely healed and subsequently disintegrates. The biggest problem associated with the biodegradability of Mg alloys is their high rate of corrosion with the development of hydrogen bubbles. This work was therefore focused on the evaluation of the corrosion behavior of an alloy based on Mg-Ca-Zn-Mn in a solution of artificial plasma. The theoretical part discussed the properties of Mg alloys, including their biodegradation and use in biomedicine. Some methods have been reported to control corrosion rate and increase corrosion resistance. In the experimental part, the character of the microstructure of two prepared alloys after heat treatment and after ECAP was studied by means of optical microscopy. Analyzes confirmed the presence of intermetallic phases. Corrosion properties were tested and evaluated by potentiodynamic and immersion testing. Corrosion rates and surface condition after testing were evaluated.