|About this Abstract
||2021 TMS Annual Meeting & Exhibition
||Magnesium Technology 2021
||In situ study of Mg-Zn alloy degradation mechanisms towards advancing in vitro testing
||Max Viklund, Lars Wadsö, Dmytro Orlov
|On-Site Speaker (Planned)
Mechanisms of magnesium degradation in aqueous media still have many open questions because of complexity of the process and limitations of existing experimental methods. Development of the latter is critically important for advancing in vitro assessment of bio-degradable implant materials based on Mg alloys.
Combining isothermal calorimetry with pressure measurements in a reaction cell during immersion testing allows in situ quantitative analysis of chemical reactions based on direct access to process thermodynamics, which is complementary to more traditional potentio- dynamic testing.
We carried out in situ measurements of enthalpy, H2 generation and pH-factor evolution upon immersion of pure Mg and Mg-5%Zn alloy into 0.9%NaCl water solution and simulated body fluid. Mg degradation kinetics seems to be linear before and logarithmic after the saturation of pH. In Mg-5%Zn alloy, the kinetics return to linear after 15h, at which point degradation rate and enthalpy start increasing, which is associated with secondary reaction.