TiAlV/Al2O3/TiNi shape memory alloy smart composite biomaterials for orthopedic surgery

The structure and properties of TiNi/Al2O3/Ti-alloy composite implant materials consisting of a Ti-alloy body and active TiNi shape memory elements is discussed The structure of composites and ceramic/metal interfaces were evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), accompanied with energy and wave dispersive X-ray microanalysis (EDX, WDX). Mechanical testing of composite materials was performed using an Inova tensile/compression test machine. Bone/implant interaction and design parameters are also discussed. The structure of the TiNi alloy is modified in the casting process. Similar effects to those observed in the annealing process occurred in TiNi materials during casting and cooling of composites. The Ti-alloy matrix is composed of a mixture of α and β phases. The interaction between the ceramic layer and the metallic components depends on the cooling rate in the casting process. Different reaction products were identified on the Al2O3/metal interface with dependence on the applied cooling rate of the composite. The fatigue life of the investigated composites is greater than 107 cycles, and mechanical properties are sufficient to carry loads expected in human medicine. A newly developed smart implant enables quasielastic fixation with an active role of bone tissue in load carrying process, which has a positive impact on treatment.