Morphological and microstructural characterization of nanostructured pure α-phase W coatings on a wide thickness range

• DOI: 10.1016/j.apsusc.2014.07.061
• Publication Date: 2014-07-19T18:16:44Z
• Authors: N. Gordillo; M. Panizo-Laiz; E. Tejado; I. Fernandez-Mart...; A. Rivera; J.Y. Pastor; C. Gómez de Castro; J. del Rio; J.M. Perlado; R. Gonzalez-Arrabal
• Keywords: Materiales; 0103 physical sciences; Nanostructured tungsten; Sputter deposition; 02 engineering and technology; 0210 nano-technology; Micro-/macro-stresses; 01 natural sciences; Ingeniería Industrial; Nanoindentation; 3. Good health

© 2014 Elsevier B.V. All rights reserved. Nanostructured tungsten (nanoW) coatings have been deposited by DC magnetron sputtering. First, the influence of the sputtering power on the adhesion of the coatings to the substrate was investigated by depositing coatings at powers varying from 30 up to 220W. Non-delaminated coatings were achieved at powers ≤50W. Second, the influence of coating thickness on the morphological, microstructural and mechanical properties was investigated for films deposited at 50 W with thicknesses varying from 30 nm up to ∼4.0 μm. SEM images reveal that all the films are highly compact, consisting of nanometer sized columns that grow perpendicular to the substrate. XRD data evidence that films are monophasic, being made of pure a-phase. All coatings show compressive stress and low micro-strain. Nanoindentation tests show that coatings have a hardness higher than that reported for coarse grained W. No significant dependence of the previous properties on coating thickness was observed. Finally, the influence of the substrate on coatings properties was studied, by depositing a W coating at a power of 50W on a commercial steel substrate: no significant dependence was found.<br/>Research by N. Gordillo was supported by a Program for International Talent Recruitment (PICATA) postdoctoral fellowship of the Moncloa Campus of International Excellence (UCM-UPM). E. Tejado was supported by the CSIC (JAE-Predoc program) co-financed by FSE supports. I. Fernandez-Martinez was supported by a JdC program. This research was supported by Comunidad de Madrid (S-S2009/MAT-1585), EFDA-ITER (WP12-MAT-W ALLOY), Ministry of Economy and Competitiveness of Spain Government (ENE2012-39787-C06-0XX and MAT2012-38541-C02-01 and MAT2012-38541-C02-02).<br/>Peer Reviewed<br/>