Mechanical and Corrosion Behavior of a Biomedical Mg-6Zn-0.5Zr Alloy Containing a Large Number of Twins

The strong texture of Mg alloys can lead to strong tension-compression yield asymmetry and corrosion anisotropy, and this will consequently affect the effectiveness of hard tissue implants. A biomedical Mg-6Zn-0.5Zr alloy containing a large number of {10 (1) over bar2} primary twins and {10 (1) over bar2}-{10 (1) over bar2} secondary twins is successfully prepared by cross compression. The dual twin structure not only removes the tension-compression yield asymmetry completely, but effectively reduces the corrosion anisotropy without compromise of corrosion resistance. The difference between the largest corrosion rate and smallest one is similar to 1.2 times compared to similar to 1.6 times of the original materials. It is found that the reduced corrosion anisotropy is related to re-distribution of crystallographic orientations by twins.

Automated summary

The dual twin structure in a biomedical Mg-6Zn-0.5Zr alloy can eliminate tension-compression yield asymmetry and effectively reduce corrosion anisotropy.