Microstructure and elastic deformation behavior of beta-type Ti-29Nb-13Ta-4.6Zr with promising mechanical properties for stent applications

Autor(es)

Plaine, Athos H. ^{[1, 2]} ; da Silva, Murillo R. ^{[3, 1]} ; Bolfarini, Claudemiro ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Mat Engn, Rod Washington Luis Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Santa Catarina State Univ, Dept Mech Engn, Paulo Malschitzki 200, BR-89219710 Joinville, SC - Brazil

^[3] IFW Dresden, Inst Complex Mat, Helmholtzstr 20, D-01069 Dresden - Germany

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T; v. 8, n. 5, p. 3852-3858, SEP-OCT 2019.
• Citações Web of Science: 0

Resumo

In this paper, an attempt was made to combine theoretical composition design and thermo-mechanical treatments to produce a metastable beta-type titanium alloy with mechanical compatibility for self-expandable stent applications. Metastable beta-type Ti-29Nb-13Ta-4.6 Zr (wt.%) thin-wires with an elastic modulus of 46 GPa and a yield strength of 920 MPa were successfully fabricated by cold rolling and low temperature aging. This combination of high yield strength and comparatively low elastic modulus resulted in enhanced elastic recoverable strain of 1.9%, which is much higher than that of the conventional metallic stent materials. The microstructure responsible for the much sought-after mechanical properties was observed to be mainly consisted of a homogeneous distribution of nanometer-sized alpha-precipitates in a beta-phase matrix obtained via a spinodal decomposition of the pre-existed alpha `'-martensite phase through alpha `' -> alpha `' lean + alpha `' rich -> alpha+beta. The alpha-precipitates increase the strength of the material by hindering the motion of dislocations (spinodal hardening) while the beta-matrix with relatively low content of beta-stabilizers gives rise to the observed low elastic modulus. More broadly, these findings could be extended to developing advanced metastable beta-type titanium alloys for implant and other engineering applications. (C) 2019 The Authors. Published by Elsevier B.V. (AU)

• Processo FAPESP: 16/17502-7 - Desenvolvimento e caracterização de novas ligas de titânio para aplicação em endopróteses vasculares (stents)
• Beneficiário: Athos Henrique Plaine
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado