title: In-situ laser synthesis of Nd-Al-O coatings: the role of sublattice cations in eutectic formation.
abstract: Neodymium aluminate coatings have been prepared in-situ by the laser zone melting (LZM) method, using a CO2 SLAB-type laser emitting at 10.6 µm. Polycrystalline Al2O3 commercial plates have been used as substrates, and coatings were prepared from the corresponding mixtures of powdered neodymium and aluminium oxides as starting materials. Microstructure, studied by SEM and phase composition, studied by XRD, proved the in-situ formation of a NdAlO3/NdAl11O18 eutectic. As a result, a well integrated composite coating was formed. Nanoindentation tests are consistent with excellent integration between coating and substrate. Structural similarities between the eutectic components within the coating, as well as between these and the substrate, are consistent with the crystallographic concepts proposed by Vegas (Ramos-Gallardo & Vegas, 1997), where cation sub-arrays play an important role governing metal oxide structures. These structure sublattices are suggested as the driving force behind eutectic oxide formation.
authors: Instituto de Ciencia de Materiales de Aragón (CSIC - University of Zaragoza), E-50018 Zaragoza, Spain.
authors: Isabel
authors: I
authors: de Francisco
authors: Group of Applied Modeling and Instrumentation (GIMA), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain.
authors: Jose Antonio
authors: JA
authors: Bea
authors: Universidad de Burgos, Hospital del Rey s/n, E-09001 Burgos, Spain.
authors: Angel
authors: A
authors: Vegas
authors: Departamento de Química Inorgànica y Orgànica, Universitat Jaume I, E-12071 Castellón de la Plana, Spain.
authors: Juan Bautista
authors: JB
authors: Carda
authors: Instituto de Ciencia de Materiales de Aragón (CSIC - University of Zaragoza), E-50018 Zaragoza, Spain.
authors: German Francisco
authors: GF
authors: de la Fuente
keywords: alumina; cation subarrays; ceramic coatings; eutectics; laser synthesis; mechanical properties; nanoindentation; oxides; rare earth aluminates