Influence of TiC nanoparticles on microstructures and properties of electrodeposited Ni–P coatings

Electrodeposited composite coatings show large development potential, thanks to particular properties obtained by the incorporation of particles. In the present work, Ni–P and Ni–P/nano-TiC coatings were electroplated on steel substrates. X-ray diffraction technique, scanning electron microscopy, energy-dispersive analytical X-ray, microhardness, potentiodynamic polarisation and electrochemical impedance spectroscopy were utilised to study the influence of addition TiC nanoparticles and heat treatment on corrosion resistance and physical properties of the applied coatings. The TiC nanoparticles were found to be embedded in the Ni–P alloy matrix and post heat treatment resulted in NixPy phase precipitation which caused the increasing microhardness of deposits. Electrochemical impedance spectroscopy and polarisation tests showed that the addition of nano-TiC particles and proper heat treatment demonstrated significant increase in corrosion resistance of Ni–P coatings in 3.5 wt.% NaCl solution.