- ICOMAT 2017
- July 09, 2017 - July 14, 2017
- Chicago, IL
QuesTek's Dr. Dana Frankel will be giving a presentation:
1. Design of Heusler-strengthened Shape Memory Alloys for Biomedical Applications
Authors: Dr. Dana Frankel, Dr. Ida Berglund, Dr. Jason Sebastian, Dr. Greg Olson
NiTi-based SMAs are used in a wide variety of medical applications, most commonly vascular stents which require excellent fatigue performance to prevent device failure and negative clinical outcomes. The development of novel, low-Ni, precipitation-strengthened SMAs utilizing an Integrated Computational Materials Engineering (ICME) approach, including mechanistic process-structure and structure-property models, allows for the parametric design of a highly biocompatible, radiopaque, and fatigue-resistant SMA. The austenite finish temperature is modeled using a 2-sublattice Redlich-Kister polynomial, while the compositional dependence is captured through a thorough understanding of Heusler phase precipitation kinetics, elemental partitioning, and particle size evolution, informed by advanced characterization techniques such as Atom Probe Tomography (APT). Excellent functional fatigue resistance has been demonstrated in precipitation-strengthened prototypes. Novel processing routes, including rapid solidification techniques, are also investigated in order to mitigate the formation of embrittling phases and refine non-metallic inclusion structures for improved strength and fatigue resistance.