4. Summary

Magnesium is a promising material for biomedical applications. Because body parts such as hip joints, bones and knees are subjected to cyclic loading fatigue is an essential tool for designing implants and replacement components for these parts. Accurate determination of the stress and strain states is critical for a successful fatigue design process. Magnesium has a hexagonal close packed crystal structure resulting in a complex stress-strain behaviors. It has been explained that the involvement of slipping, twinning and detwinning deformation mechanisms causes the unusual cyclic hysteresis loop of wrought magnesium alloys. Therefore, suitable cyclic plasticity model is required for estimating the cyclic stress-strain state. Different fatigue damage models such as stress-, strain- and energy-based parameters can be used to correlate the fatigue damage with life. Although biodegradability is an attractive characteristic of biomedical materials, the high reactivity of magnesium in electrolytic or aqueous environments calls for further developments. The properties of magnesium and its alloys can be improved by reinforcing them using selected reinforcements.
