An innovative surface treatment method, ultrasonic nanocrystal surface deformation (UNSM), was used to process a magnesium (Mg) AZ31B alloy in this study. In the UNSM process, ultrasonic impacts induce plastic deformation on material surface that lead to grain refinement and surface morphology changes. The hardness, tensile strength, surface morphology and weight loss from immersion testing of the materials before and after UNSM were studied systematically. Compared with the unprocessed samples, the UNSM-processed samples show significant improvements in hardness (64%) and yield stress (43%). Surface topography results reveal that UNSM generates a smooth surface with an average roughness of 93 nm. In addition, the immersion results in cell medium demonstrate that the UNSM-processed group showed lower weight loss, especially during the early immersion period. It can thus be concluded that UNSM can significantly improve the hardness and yield strength of Mg alloys and reduce the corrosion rate, indicating that UNSM is a promising new method to enhance the mechanical properties of the degradable Mg alloys.

This content is only available via PDF.
You do not currently have access to this content.