12th International Conference on Magnesium Alloys and their Applications (Mg 2021): Biomedical Applications I
Program Organizers: Alan Luo, Ohio State University; Mihriban Pekguleryuz, McGill University; Sean Agnew, University of Virginia; John Allison, University of Michigan; Karl Kainer; Eric Nyberg, Kaiser Aluminum Trentwood; Warren Poole, University of British Columbia; Kumar Sadayappan, CanmetMATERIALS; Bruce Williams, Canmetmaterials Natural Resources Canada; Stephen Yue, Mcgill University

Tuesday 9:50 AM
June 15, 2021
Room: Invited IV
Location: Virtual

Session Chair: Michele Manuel, University of Florida


9:50 AM  Invited
In-vivo Degradation and Hydrogen Gas Development in Low Alloy Content Magnesium Alloys: Matthew Dargusch1; Nan Yang1; Jeffrey Venezuela1; Nagasivamuni Balasubramani1; Sean Johnston1; Karine Mardon1; Cora Lau1; Rachel Allavena1; David St John1; 1University of Queensland
    The in-vivo degradation rates of a range of low alloy content magnesium alloys suitable for the manufacture of medical implant devices has been explored and compared to the in-vivo corrosion rates of the commercial WE43 alloy. The degradation behaviour of the alloys was carefully measured using in-vivo weight loss measurements and the biocompatibility of each of the alloys has been evaluated using detailed histological analysis. Differences in the corrosion behaviour are explained in terms of alloy microstructure. Degradation behaviour was found to be associated with the development of hydrogen gas in the implanted specimens. The evolution of hydrogen with time and related histological effects were also examined in this study using CT scan information and related histological evaluation.

10:20 AM  Invited
Effect of LPSO Phases on Crack Propagation in an Extruded Mg-Dy-Nd-Zn-Zr Alloy Influenced by Heat Treatment: Petra Maier1; Benjamin Clausius1; Norbert Hort2; 1University of Applied Sciences Stralsund; 2Helmholtz Zentrum Geesthacht
    The effect of LPSO-phases on the crack propagation in different microstructures modified by heat treatment is investigated. Solution heat treatment on a hot extruded RESOLOY (Mg-Dy-Nd-Zn-Zr) has been done to change the initial fine-grained microstructure, consisting of lamellar LPSO structures within the matrix, into coarser grains of less lamellae but more bulk LPSO-phases. Crack initiation and propagation are of interest. Since the coarser microstructure tends to twin under plastic deformation, the crack propagation is also influenced by twin boundaries. The bulk LPSO-phases clearly hinder crack growth, either by increasing the energy to pass through the phase or along its interface. Twin boundaries and LPSO-phases are also responsible for crack initiation. The microstructural features were characterized by micro- and nanohardness as well as the amount and location of LPSO-phases in dependence on the heat treatment condition. Bulk LPSO-phases show a higher hardness than the grains with or without lamellar LPSO-phases.