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Bethel, CT, United States

Li K.,Beihang University | Li K.,Northumbria University | Huang X.,Memry Corporation | Zhao Z.S.,Taiyuan University of Technology | And 2 more authors.
Smart Materials and Structures | Year: 2016

Electrochemical and corrosion behaviors of TiNi-based shape memory thin films were explored using electrochemical impedance spectroscopy (EIS) and polarization methods in phosphate buffered saline solutions at 37°C. Compared with those of electro-polished and passivated bulk NiTi shape memory alloys, the break-down potentials of the sputter-deposited amorphous TiNi films were much higher. After crystallization, the break-down potentials of the TiNi films were comparable with that of the bulk NiTi shape memory alloy. Additionally, variation of composition of the TiNi films showed little influence on their corrosion behavior. The EIS data were fitted using a parallel resistance-capacitance circuit associated with passive oxide layer on the tested samples. The thickness of the oxide layer for the TiNi thin films was found much thinner than that of bulk NiTi shape memory alloy. During electrochemical testing, the oxide thickness of the bulk alloy reached its maximum at a voltage of 0.6-0.8 V, whereas those of TiNi films were increased continuously up to a voltage of 1.2 V. © 2016 IOP Publishing Ltd. Source


Coda A.,SAES Getters S.p.A. | Zilio S.,SAES Getters S.p.A. | Norwich D.,Memry Corporation | Sczerzenie F.,Smart USA
Journal of Materials Engineering and Performance | Year: 2012

Inclusions content is important for the mechanical behavior and performances of NiTi-based products particularly in fatigue-rated devices. Higher inclusions content has been correlated to reductions in transformation temperatures and strain recovery under mechanical or thermo-mechanical cycling. Moreover, most fatigue fractures show inclusions at the initiation site. However, there is a general lack of information on the nature and characteristics of such inclusions, especially those typically recognized as intermetallics oxides. In this study, the common scanning electron microscopy technique has been used to investigate the chemistry and morphology of inclusions in commercial standard VIM/VAR binary NiTi alloys. The defined experimental procedure, results, and their significance will be presented and discussed. © ASM International. Source


Norwich D.W.,Memry Corporation
Journal of Materials Engineering and Performance | Year: 2012

After gamma sterilization of a packaged medical device, fractures were discovered in the superelastic nitinol wire used as part of the assembly. The nitinol wire was encased in fluorinated ethylene propylene (FEP) shrink tube. The only fractures occurred where the encased wire was held under strain during gamma sterilization. A study was conducted to determine the susceptibility of nitinol to this type of failure. The variables studied included wire diameter, wire surface finish, wire oxide layer, quantity of wires encased, type of tubing, and strain level during gamma sterilization. The greatest susceptibility to fracture occurred to single wire samples with a light oxide layer held under high strain in FEP shrink tube. Gamma sterilization experiments were conducted to isolate and confirm this failure mechanism. Scanning electron microscopy was used to analyze the fractured samples. Chemical analysis was performed in an attempt to detect trace elements to determine the root cause of the failures. Stress corrosion cracking caused by the liberation of fluorine due to the degradation of the polymer during gamma sterilization is suspected. © ASM International. Source


Trademark
Memry Corporation | Date: 2006-05-01

Electric actuators comprised of metal. Medical instruments made of metal alloys, namely, minimally invasive endovascular surgical devices; medical components made of metal alloys, namely, minimally invasive endovascular surgical devices; medical components and assemblies, namely, minimally invasive endovascular surgical devices. Extruded polymer tubing, film and solid pellets which are melted and extruded on rods and wires in the nature of coatings, for use in manufacture of medical catheters. Polymer extrusion for others, namely, extruding polymer to form medical catheters; injection molding for others in the nature of parts molding for medical instruments; custom tooling, namely, custom manufacture of medical tools for others; coating for others, namely, application of protective coatings in the field of medicine and medical instruments. Engineering research in the filed of medicine and medical instruments.


Trademark
Memry Corporation | Date: 2011-05-23

Metal alloys for use in further manufacturing. Metal actuators, namely, electrical and thermal actuators. Medical instruments made of metal alloys, namely, minimally invasive endovascular surgical devices; medical components made of metal alloys, namely, minimally invasive endovascular surgical devices; medical components and assemblies, namely, minimally invasive endovascular surgical devices; medical device parts, namely, stents, guide-wires, articulators, organ retrieval instruments, namely, organ retrieval bag for laparoscopic surgery; minimally invasive surgical instruments, namely, laparoscopic surgical instruments, all made at least partially of metal alloys. Plumbing fixtures, namely, valves and structural and replacement parts therefor, made of metal alloys. Custom metallurgical services for production shape memory alloy components; specialized machining of metal alloy components; joining, welding, crimping and adhesion of metal alloys; custom grinding of metal alloy components; coating and plating of metal alloy components; shape setting and heat treatment of metal alloys; coiling of metal components; laser cutting of metal components; surface treatments for metals; melting, milling and manufacture of nickel-titanium alloy products. Metallurgical and engineering research and new product development; metallurgical analysis and testing; Engineering research in the field of medicine and medical instruments.

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