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Codeposition of alumina particles within a Ni-P matrix was investigated. These composite coatings were produced on AISI 1045 steel discs by an electroless process and then heat treated at 200, 400 and 600uC for 1 h. Wear resistance of the deposits was measured by the pin on disc method. Structural changes were evaluated by X-ray diffraction (XRD) analysis, and SEM was used to study the surface morphology, cross-sections of coatings, wear surfaces and debris. The volume of codeposited particles was determined using an image analysis system. The results showed that alumina content in the bath to 15 g L -1 led to an increase in both the hardness and the wear resistance of the coatings. It was also found that heat treatment at about 400uC can increase the hardness and wear resistance of these composite coatings to maximum values.

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Pure nickel and Ni-TiO 2 composite coatings were deposited on the copper substrate using Watts bath containing different contents of TiO 2 nanoparticles by the electrochemical deposition method, and the morphological alterations and hydrophobicity of coatings were studied. Field emission scanning electron microscopy (FESEM) images proved that composite coatings exhibited a rougher structure than pure nickel coating. The results of the roughness measurement performed by AFM confirmed this fact. The water contact angles (WCA) of pure nickel and the composite coatings were obtained as 62.7°and 91.6-121.7°, respectively. After surface chemical modification using the different concentrations of TMPSi, WCA of pure Ni and optimized composite coatings (Ni-27.5 g.L −1 ) were increased to 102.1°and 140.3°, respectively.