For biomedical applications, materials have to be highly multifunctional. For instance, biocompatibility and corrosion resistance can be required as well as low density and specific mechanical properties. Magnesium alloys are already identified for their high potential in such functionalities. However biomedical device may have specific requirements depending on the applications, it is then worth to have a strategy allowing for a fine tuning of properties. As functionality requirements can be schematically described as bulk and surface properties, we propose a 2D/3D strategy: i.e. design the surface patterning to fulfil the specification for bioapplication and design the bulk microstructure to have the required mechanical behaviour.
For surface properties, the main point will be to design surface patterning to get in a first step antibacterial effect and in further steps controlled corrosion (i.e. biodegradability). For the bulk properties, we will focus on getting by nanostructuring the appropriate strength associated to high temperature deformation necessary for shaping. The project is based on a large experimental part including elaboration, surface modification…Special attention will be also given to the interface, namely the impact of the surface modification like surface alloying across the interface, cohesion of the surface layer.
The project will rely of the complementary expertise of both research groups: advanced multi-length scale surface modification at WIN- Waterloo University (Fig. left) ; elaboration, microstructure control (Fig.right), mechanical properties and Magnesium alloys for SIMAP-Grenoble-INP . The industrial partner, Titacreuset will provide its expertise in the selection of material compositions and processes consistent with industrial production. The PhD work will start with the selection of the more appropriate composition and characteristics with the help of material selection softwares and phase diagrams to find out candidates compatible with bio-applications. In a second step, bulk materials will be prepared and tested for mechanical properties. The materials with the best properties will be characterized and further considered for the surface modification. If possible, we will try to obtain a set of solutions addressing specific applications and with eventually elaboration of prototype on larger scale with the help of our industry partner. It is planned that the PhD student will spend approximately one third of his time in Waterloo-Canada and two thirds in Grenoble-France.
Figure left: Surface patterning of a Magnesium substrate by laser-assisted microdeposition of silver nano-particles
Figure right: Nanoscale lamellar structure of the bulk resulting from eutectic solidification
INPG-SIMAP (Materials and Processes Science and Engineering Laboratory-Grenoble-France)- elaboration, bulk structuring and properties
UW-WIN (Waterloo Institute of Nanotechnolgies- Canada)- surface patterning - surface modification for bioapplication
Titacreuset France - consistence with industrial process -prototype