Table 1 presents a summary of tribological properties of electrodeposited composite coatings incorporating various metal nanoparticles with Ni matrix. It shows improved tribological performance in all kinds of composites using metal nanoparticles as filler in Ni matrix. The effect of electrodeposition conditions for direct current (DC), pulse current (PC) and pulse reverse current (PRC) for pure nickel and Ni-based composite on sliding wear behaviour are investigated by Borkar and Harimkar (Borkar, T. and Harimkar, S. P., 2011). It was demonstrated that for all pulse conditions the nickel composite coatings showed enhanced wear resistance than pure nickel coatings. Furthermore particles enforcement improved with pulse current (PC) and pulse reverse current (PRC) conditions when compared to direct current (DC) and Ni-Al2O3 exhibited better wear resistant properties when
current density on wear resistance performance of nickel and nickel composite of TiO2 was investigated by Denny and Andreas(Denny, T. and Andreas, B., 2008). It was concluded that the wear resistance of Ni-TiO2 composite enhanced with decreasing current density which increased the hardness and refined the nanocrystalline grain size.
The deposition pulse frequency was identified as a dominant factor to optimize the grain size, microhardness and corrosion resistance properties of Ni-W coatings (Argañaraz, M. et al., 2011). Abdel Aal et al, determined the optimum electrodeposition parameters and concentration (41 wt.%) of incorporated nanoparticles of aluminium nitride (1-40-150nm) into Ni matrix for improved tribological performance in term of wear resistance, corrosion resistance and coefficient of friction (Aal, A. A. et al., 2006). Tribo-tests were conducted subject to room temperature under a load of 500 g and sliding speed of 70 rpm. It was demonstrated that the composite coatings of Ni-AlN significantly enhanced the tribological performance in comparison to nickel coatings. The wear and friction behaviour of electroplated Ni-Si3N4 with focus of ionic liquid lubrication under ball on disc sliding rig studied by Yanqiu Xia et al. (Xia, Y. et al., 2007). It was presented that the tribological properties of co-deposit coatings were excellent under ionic lubrication. The friction and wear tests were conducted under a load of 10 N and sliding speed of 0.055 m s-1.
Gül and co-workers studied the influence of current density on the tribological performance of Ni-alumina co-deposited by using direct current and PC methods (Gül, H. et al., 2009; Gül, H. et al., 2014). It was concluded that the co-deposit composite coatings manufactured by PC technique resulted into an increased percentage of incorporated particles and also with enhanced particle distribution within the matrix. It was found that the wear rate of coatings produced by using DC technique was reduced with increasing current density. On the other hand, no significant influence of current density was observed in coatings produced by using PC technique.
An optimum value for immersed particles (Gül, H. et al., 2012) and sodium dodecylsulfate (SDS) (Kartal, M. et al., 2015) into electrodepositing electrolyte has been reported in literature as 20 gram per litre and 0.10 gram
per litre respectively in order to achieve better mechanical and tribological properties of electroplated Ni-silicon carbide and Ni- tungsten carbide composite coating.
Beltowska-Lehman et al (Beltowska-Lehman, E. et al., 2015) investigated the effect of ultrasonic treatment on Ni-ZrO2composite coatings. It was established that the composite coatings Ni-W/ZrO2 showed the uniform distribution and a greater content of particles subject to lower ultrasonic treatment. It was the reason for the enhanced mechanical properties of developed coatings. The corrosion resistance behaviour of nickel alumina composite coatings as a function of incorporated nano- alumina particles was investigated by Zhou et al (Zhou, Q. et al., 2009). It was proved that the integration of nano-alumina particles increases the corrosion resistance, reducing the porosity of the coatings and also increases the abrasion resistance. It was because of the better dispersion of nano- sized particles with respect to the micro-sized particles. The effect of depositing pulse frequency on the wear behaviour of nanocomposite coatings under sliding contact was studied by Chen et al.(Chen, L. et al., 2006). It was indicated that the volume fraction of alumina particles in coatings increased with the increase of pulse frequency and the wear behaviour of coating depend on reinforcement content of the particles into coating rather pulse frequency. It was confirmed that the wear properties of electrodeposited coatings as a function of changing pulse frequencies act significantly dissimilar subject to dry and oil lubricated situations.
Earlier, researchers have studied the influences of chemical composition strength (ionic concentration) of electrolyte on surface morphologies of coatings produced by electroplating method (Bełtowska- Lehman, E. et al., 2011). It was established that the lower ionic strength of electrolyte results into good particle distribution within the nickel matrix, also the refined microstructure of deposited pure nickel and nickel co-deposit of alumina nanoparticles. The volume of electroplating bath also contribute to the characteristics of deposit coating as researchers reported in the literature (Oloruntoba, D. et al., 2010). It was observed that the coating deposition time
Table 1 A summary of the tribological properties of some nanoparticles-filled metal nanocomposites. Matrix/nanop
articles
Filler Size (nm) Method Change of H Change of COF Wear resistance Corrosion
resistance Reference Ni/Al2O3 50-150 DC,PC ~450 ~0.2 – 0.25 ↑ ↑ (Borkar, T. and Harimkar, S. P., 2011; Zhou, Q. et al., 2009) Ni/SiC 50 PC ~650 ~0.29 – 0.34 ↑ ↑ (Vaezi, M. et al., 2008; Wielage, B. et al., 2008) Ni/ZrO2 100 PC ~434-446 `- ↑ ↑ (Benea, L., 2009; Kumar, K. A. et al., 2012) Ni/TiO2 21 DC ~400-450 ~0.66 – 0.75 ↑ ↑ (Denny, T. and
Andreas, B., 2008; Lampke, T. et al., 2006; Wang, Y. et al., 2014) Ni/W 60-150 PC ~650-850 ~0.30 – 0.40 ↑ ↑ (Argañaraz, M. et al., 2011; Surender, M. et al., 2004b) Ni/AlN 40-150 DC ~650 ~0.012 – 0.016 ↑ ↑ (Aal, A. A. et al., 2006) Ni/Si3N4 100 DC ~484 ~0.04 – 0.06 ↑ - (Xia, Y. et al., 2007) Ni/CeO2 40 DC,PC ~360-400 ~0.48 – 0.52 ↑ ↑ (Aruna, S. et al., 2006; Xue, Y.-J. et al., 2006; Xue, Y.-J.
Ni/Fe2O3 <100 DC ~300-320 ~0.25 – 0.30 ↑ ↑ (Haq, I. U.
et al., 2013)
Ni/SnO2 <100 DC ~450-480 ~0.22 – 0.35 ↑ - (Khan, T. I.,
Table 2 provides a summary of recent research papers related to electrodeposited nanocomposite coatings with different process method used to examine the friction, wear and corrosion properties of coatings. The key investigations demonstrate that the results are quite dependent to the experimental condition of both electrodeposition parameters and configuration parameters of tribo test methods used. Table 3 demonstrates a summary of the key results of the investigation related to effect of configuration parameters such as testing method, sliding velocity, contact frequency, contact area, temperature and coating material on wear and friction coefficient properties.