title: Synthesis of MAX Phases in the Zr-Ti-Al-C System.
abstract: This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCnsystem. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350-1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard's law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard's law around the (Zr0.33,Ti0.67)3Al1.2C1.6stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system.
authors.affiliation: SCK•CEN , Boeretang 200, B2400 Mol, Belgium.|KU Leuven , Department of Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
authors.forename: Bensu
authors.identifier: http://orcid.org/0000-0001-8611-3636
authors.initials: B
authors.lastname: Tunca
authors.affiliation: SCK•CEN , Boeretang 200, B2400 Mol, Belgium.|KU Leuven , Department of Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lapauw
authors.affiliation: University of Antwerp , Department of Physics, Electron Microscopy for Materials Science (EMAT), Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Olesia M
authors.initials: OM
authors.lastname: Karakulina
authors.affiliation: University of Antwerp , Department of Physics, Electron Microscopy for Materials Science (EMAT), Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Maria
authors.initials: M
authors.lastname: Batuk
authors.affiliation: Institut Pprime , UPR 3346, CNRS-Université de Poitiers-ENSMA, SP2MI, Téléport 2-BP 30179, 86962 Futuroscope Chasseneuil Cedex, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Cabioc'h
authors.affiliation: University of Antwerp , Department of Physics, Electron Microscopy for Materials Science (EMAT), Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Joke
authors.initials: J
authors.lastname: Hadermann
authors.affiliation: SCK•CEN , Boeretang 200, B2400 Mol, Belgium.
authors.forename: Rémi
authors.initials: R
authors.lastname: Delville
authors.affiliation: SCK•CEN , Boeretang 200, B2400 Mol, Belgium.
authors.forename: Konstantina
authors.initials: K
authors.lastname: Lambrinou
authors.affiliation: KU Leuven , Department of Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Vleugels