Shape memory alloy articles with improved fatigue performance and methods therefore
US8709177B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 2012 |
| Grant date | Apr 29, 2014 |
| Priority date | — |
| Expiry date | Jul 10, 2032 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61L2400/16
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
Articles made of shape memory alloys having improved fatigue performance and to methods of treating articles formed from shape memory alloy materials by pre-straining the articles (or desired portions of the articles) in a controlled manner so that the resultant articles exhibit improved fatigue performance. The shape memory articles are preferably medical devices, more preferably implantable medical devices. They are most preferably devices of nitinol shape memory alloy, most particularly that is superelastic at normal body temperature. The pre-straining method of the present invention as performed on such articles includes the controlled introduction of non-recoverable tensile strains greater than about 0.20% at the surface of a desired portion of a shape memory alloy article. Controlled pre-straining operations are performed on the shape-set nitinol metal to achieve non-recoverable tensile strain greater than about 0.20% at or near the surface of selected regions in the nitinol metal article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.