Composite coatings electroplating could be a valid and relatively low cost production method to codeposite either
micro- or nano-particles of Al in Ni matrix. The aim of this work is the production of Ni matrix composite
deposits containing either micro- (3–4 μm) or nano- (130 nm) particles of Al using parallel plate geometry composite
plating and their characterization both prior and after heat treatments at different temperatures by means
of microstructure and microhardness. The obtained electrodeposits both before and after heat treatments at different
temperatures have been observed by SEMin cross section both prior and after metallographic etching and
analysed by XRD in order to evaluate the formation of Ni/Al phases. After heat treatment at 600 °C the microcomposite
coating consisted of a biphasic γNi and γ′Ni3Al system, while after heat treatment at 800 °C of a
solid substitutional solution of Al in the γNi. The diffusion of Al in the metal matrix hindered the recrystallization
of the Ni matrix and the change of the preferential orientation. The more uniform distribution of the Al nano-particles
and the smaller dimensions lead to an advance of the diffusion at lower temperature (400 °C). The heattreated
nano-composite deposits consist of γNi and present a columnar structure with narrow ad short columns
as the fast diffusion of Al blocked the recrystallization of the Ni matrix.
