Different Analytical Methods to Determine the Influence of Pitting on the Residual Performance of Mg Alloys as Implant Materials

Mg alloys are prone to pitting due to their non-uniform protective corrosionCorrosion layers, which can lead to an increase in stress intensity based on the notch effect, pit-to-crack transition, and thus premature failure. A small set of analytical methods to determine the extent of pitting and its effect on the resulting residual strengthResidual tensile strength is presented. Micrographs, 3D microscopy, or 3D analysis using CT are used to determine the amount and geometry of pitting—each with advantages and disadvantages. The influence of the corrosion pits on the mechanical propertiesMechanical Properties is tested by static, quasi-static, and cyclic test methods: by tensile, flexural, or fatigueFatigue testing—either after corrosionCorrosion or overlapping. Knowledge about the critical pit is of general interest. Stress corrosion is discussed by applying static tests like C-ring testing, which also plays a role in slow strain rate tensile testsTensile test and stress corrosion cracking is more or less influenced by corrosion pits.