Studying the effects of the addition of TiN nanoparticles to Ni–P electroless coatings

► The surface morphology and deposition rate of Ni–P/TiN nano-composite electroless coatings were investigated. ► The addition of TiN nano particles to the Ni–P matrix enhanced the hardness of the coatings. ► Heat treatment at 400 °C improved the hardness of coatings while the hardness of specimens after heat treatment at 200 °C remained unchanged. ► The addition of TiN nano particles to the Ni–P matrix adversely affected the corrosion properties. ► Heat treatment at 200 °C improved the corrosion properties of the Ni–P specimen while heat treatment at 400 °C had a negative effect on the corrosion properties of both Ni–P and Ni–P/TiN systems. The effects of the addition of nano TiN on the surface morphology, deposition rate, hardness and corrosion properties of Ni–P electroless coatings were studied. Heat treatment was conducted to compare the corrosion and hardness behavior of the coatings before and after heat treatment. It was observed that the incorporation of TiN particles into the coating has an adverse effect on the corrosion properties of the specimens. The hardness of the specimens increased dramatically by adding TiN. Furthermore, the hardness of the specimens increased after conducting the heat treatment. The corrosion and hardness behavior of the Ni–P system after heat treatment largely depended on the temperature of heat treatment. The heat treatment temperatures at which the desired corrosion and hardness properties were expected were determined.