Process-Performance Tuning of NiTiPt Alloys for Medical and Elastocaloric Applications—Part I

Abstract The late John Boylan and his team in Temecula, CA, filed a patent in the 1990’s that included a variety of radiopaque ternary additions to a nitinol alloy. Several of these elements including Pt, Pd, and Au, hold potential to not only raise x-ray attenuation, but also to perfect the interface between parent and daughter phases thereby increasing certain material performance aspects. Work is needed to understand and apply specific Ni-Ti-Pt chemistries and understand their practical utility. As early as 1988, one way shape memory, superelasticity, and austenitic transformation temperatures from about 0 to 1000°C were demonstrated for the Ni-Ti-Pt system by Lindquist and colleagues at University of Illinois Urbana-Champaign. Under equilibrium, stress-free conditions, the material composition for maximum austenite-martensite interface compatibility is approximately Ti50Ni42.5Pt7.5. Further study is warranted since improved crystallographic compatibility may improve the structural and functional performance of critical medical and industrial subcomponents where performance gains could pay for higher initial material costs.