Crystallographic features of the Al3Nb, Nb2Al and Nb(Ni-1 (-) Al-x(x))(2) phases in a directionally solidified ternary eutectic microstructure

Autor(es)

Lopes, Eder S. N. ^[1] ; Dal Bo, Mariana R. ^[1] ; Opini, Victor C. ^[1] ; de Mello, Mariana G. ^[1] ; Rios, Carlos T. ^[2] ; Fraser, Hamish L. ^[3] ; Caram, Rubens ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Sch Mech Engn, BR-13083860 Campinas, SP - Brazil

^[2] Fed Univ ABC, Engn Modeling & Appl Social Sci Ctr, BR-09210580 Santo Andre, SP - Brazil

^[3] Ohio State Univ, Dept Mat Sci & Engn, Ctr Accelerated Maturat Mat, 1305 Kinnear Rd, Columbus, OH 43212 - USA

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS CHARACTERIZATION; v. 147, p. 303-310, JAN 2019.
• Citações Web of Science: 0

Resumo

Under directional growth, the eutectic transformation L reversible arrow Al3Nb + Nb2Al + Nb(Ni(1-x)Alx)(2) resulted in a very organized three phase microstructure. While many features of this eutectic have already been explored, crystal-lographic details of its phases are still missing. This paper aims to investigate composition and crystallographic features of a directionally solidified eutectic made up of the Al3Nb, Nb2Al and Nb(Ni1-xAlx)(2) phases. It was observed that the Nb(Ni1-xAlx)(2) intermetallic phase has the C14 structure, with composition 56.91 +/- 0.43 at.% Al, 10.11 +/- 0.12 at.% Ni and 32.98 +/- 0.53 at.% Nb. Selected area diffraction in a transmission electron microscope permitted interplanar spacings to be determined and values obtained are consistent with those in the literature. Accurate lattice parameters were determined using powder X-ray diffraction combined with Rietveld refinement. It was found that the lattice parameters of the Nb(Ni1-xAlx)(2) (x = 0.85) phase are a = 5.031 angstrom and c = 8.298 angstrom and these lattice parameters depend on Al content. (AU)

• Processo FAPESP: 13/50391-6 - Non-classical mechanisms of solid-state precipitation in Ti alloys
• Beneficiário: Rubens Caram Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular