EFFECT OF TiO2 NANOPARTICLES IN NI MATRIX ON MECHANICAL AND CORROSION RESISTANCE PROPERTIES

Abstract

Nickel (Ni) is one of the most important hard coatings. Improvement in its tribological and mechanical properties would greatly enhance its use in industry. Nanocomposite coatings of metals with various reinforced nanoparticles have been developed in last few decades. Titania (TiO2) exhibit excellent mechanical properties. It is believed that TiO2 incorporation in Ni matrix will improve the properties of Ni coatings significantly. The main purpose of the current work is to investigate the mechanical and anti-corrosion properties of the electroplated Nickel nanocomposite with a different percentage of TiO2. The results showed that the content of TiO2 and the microhardness in the Ni-TiO2 coatings first increased and reached the maximum at the loading of 20 g/L, then decreased, due to agglomeration of dioxide of Titania for high concentration of TiO2. The [200] preferred orientation for Ni pure gradually evolved to [111] orientation with increasing TiO2 nanoparticle loading. At 20 g/L of titania, we obtained the minimum crystallite size (27 nm). The anti-corrosion property of nanocomposite coating was carried out in 3.5 % NaCl electrolyte, and the result also showed that the nanocomposite coatings improve the corrosion resistance significantly. This present work reveals that incorporation of TiO2 in nickel nanocomposite coating improves corrosion resistance and mechanical properties of both hardness and corrosion resistance performances, and the improvement becomes at it maximum for 20 g/L of TiO2.