Affiliations: Biomechanics and Biomaterials Research Group, École Polytechnique, Montreal, Quebec H3C 3A7, Canada | Department of Engineering Physics and Materials Engineering, École Polytechnique, Montreal, Quebec H3C 3A7, Canada
Note: [] Corresponding author: L'Hocine Yahia, Professor and Director of Biomechanics and Biomaterials Research Group, Department of Mechanical Engineering , École Polytechnique, P.O. Box 6079, Station Centre ville, Montréal, H3C 3A7 Québec, Canada. Tel.: +1 514 340 4711, ext. 4378; Fax: +1 514 340 4611; E‐mail: [email protected].
Abstract: We investigate the behavior of NiTi porous alloys, possessing the property of shape memory, by using different characterization methods XPS, Auger, DSC and SEM. The study mainly focuses on the determination of porosity, surface characteristics and the phase transformation. In the case of porous material the biomechanical compatibility is closely related to the internal structure and porosity distribution. To describe appropriately the influence of the properties of NiTi on the memory shape, two types of materials provided by different sources has been analyzed. Despite the fact that both materials present different pores size, they exhibit an open and interconnected porosity. Our measurements show that the temperature of the inception of the martensite‐austenite phase transition occurs at 60°C, which is by 20°C greater than the body temperature. Moreover, we show that the surface characteristics can be greatly influenced by heat treatment. Furthermore, we observe that the R‐phase occurs only for one of the used materials after its heat treatment. The correlation between the composition and the other characteristics measured has been found.
