DBPapers
DOI: 10.5593/sgem2017/61/S24.022

INFLUENCE OF AL2O3 NANOPARTICLES ON HARDNESS AND WEAR RESISTANCE OF NI-P-AL2O3 COMPOSITE COATINGS PREPARED BY ELECTROLESS METHOD

L. Balint, T. Radu, A. Ciocan, S. Constantinescu
Tuesday 12 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-12-6 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 61, 163-170 pp, DOI: 10.5593/sgem2017/61/S24.022

ABSTRACT

Wear-resistant composite coatings reinforced with Al2O3 nanoparticles (20nm) obtained by electroless technique are analysed in this paper. The structure and surface morphology of coatings with alumina nanoparticles embedded in the Ni-P alloy for different quantities of alumina in the nickel-plating bath (3g/L, 5g/L and 8g/L) are presented. Nanocomposite electroless coatings are characterized by optical microscopy, XRD and SEM. Microstructure of the composites has revealed uniform distribution of Al2O3 nanoparticles and the XRD analyses revealed the presence of some distinct phases (Ni, Ni3P, Al2O3). The incorporation of particles reinforcement in the deposit improves the microhardness and wear resistance of Ni-P coatings. The behavior of the heat treated composite coatings performed isothermally at 400 0C for 1 h was discussed in relation with structural changes due to the presence of nanoparticles. Wear resistance is analysed by comparing the friction coefficient for Ni-P-nanoAl2O3 composite coating, both as-deposited and heat treated. The optical surface morphologies of coating and SEM images of deposed layer co-deposition show that the degree of embedding and dispersion of nanometer alumina are good and depend less on increasing alumina content in the electrolyte. The amount of particles incorporated is greatly influenced by the particle size.

Keywords: composite coating, nanoparticles, electroless, hardness, wear.