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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Designing NiTiAg Shape Memory Alloys by Vacuum Arc Remelting: First Practical Insights on Melting and Casting

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Alvares da Silva, Gilberto H. T. [1, 2] ; Otubo, Jorge [1]
Total Authors: 2
[1] Aeronaut Inst Technol, Dept Mat, ITASMART Grp, BR-12228900 Sao Jose Dos Campos, SP - Brazil
[2] Univ Fed Ouro Preto, Dept Met & Mat Engn, BR-35400000 Ouro Preto, MG - Brazil
Total Affiliations: 2
Document type: Journal article
Source: SHAPE MEMORY AND SUPERELASTICITY; v. 4, n. 4, p. 402-410, DEC 2018.
Web of Science Citations: 1

NiTi-based shape memory alloys are successful owing to its capacity to cover specific applications unreachable by binary NiTi. The additions of ternary, and even quaternary, elements are intended to change specific properties. Known for its antibacterial activity, Ag became an alloying element in a search for a functional biomaterial; however, the melting appears to hampering the system exploration. A special melting procedure by vacuum arc remelting was developed based on chemical and thermal analysis, via EDS, XRF, and DSC, assessing the element loss and ingot homogeneity, respectively. By alloy design, different Ag content NiTiAg SMA were produced and analyzed on as-cast condition. The melting procedure developed involves specific feedstock cares and preparation, melting, and some remelting steps. The measured chemical composition slightly differs from the nominal due to alloying element loss and the melting reaction thermodynamics. Being the lower the possible, the remelting steps were optimized to maintain the compromise between chemical composition and compositional homogeneity through the ingot, since the Ag content stabilizes along them, also indicating a limited content possible to be alloyed. Ag-yields are content-dependent, while the Ni:Ti relation is stable, being therefore the melting of NiTiAg SMA better performed by VAR than other melting routes under high vacuum conditions. (AU)

FAPESP's process: 12/15302-0 - Development of ternary NiTiAg shape memory alloy for biomedical applications
Grantee:Gilberto Henrique Tavares Álvares da Silva
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)