Design and In-vitro Characterization of Ni-free Biocompatible Shape Memory Alloys

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

0731133 Karaman The project will develop Titanium-Niobium binary and ternary alloys as an alternative to Nickel-Titanium shape memory alloys since it has better processibility, better biocompatibility, better corrosion resistance and lower modulus near the elastic modulus of human bone. This work addresses two current problems with these alloys: low transformation strains and fatigue response. The project will improve these material properties, starting first with the understanding the microstructural mechanisms in single crystal studies and then move into polycrystals, by considering ternary alloy additions and using the knowledge base developed in the single crystals, grain refinement via twinning- and transformation-induced nanocrystallization for enhanced cyclic response, texturing using combination of novel processing techniques and modeling the microstructure and texture evolution, and eventually full scale characterization. These kinds of materials are popularly used for various biomedical applications such as endovascular stents, medical and dental wires and fillers and several surgical instruments. Due to the toxicity of Nickel, there is an urgent need for the design of Nickel-free shape memory alloys with completely bio-inert constituents, less-sensitivity to impurities and inclusions, better corrosion resistance, more stable fatigue response, and predictable fatigue life. The broader impacts of this project are in the potential of a new class of biocompatible materials with improved corrosion resistance and less potential for toxicity. The research will also offer opportunities for undergraduate participation through the NSF REU program.