Casey F. Davis¹, Adam J. Griebel², Jeremy E. Schaffer², Terry C. Lowe¹, Tamás Ungár³; ¹Colorado School of Mines, ²Fort Wayne Metals, ³Eötvös University

Ultrafine grain magnesium alloys have the potential to provide a combination of properties making them suitable for absorbable medical material applications, including trauma fixation and stents. It is important to first understand how commercially viable methods of microstructure refinement can impart suitable microstructures. AZ31 was selected as a model system to which Equal Channel Angular Pressing-Conform (ECAP-C) was applied to study the range of microstructures that can be achieved. Relationships between ECAP-C processing parameters and critical microstructural features, including activated slip systems, dislocation densities, dislocation configurations, grain size distributions, grain shape anisotropy, and crystallographic textures are shown and analyzed. Experimentally measured textures are compared with the results of Taylor factor modeling. We found that ECAP-C temperature and strain path have the greatest effects on grain size refinement, grain size distribution, and dislocation configuration. Finally, we discuss how the structures induced by ECAP-C can be optimized to customize absorbability.