Nanocomposite Coatings

In addition, the impurities, especially the oxygen, can strongly decrease the hardness of nanocomposite coatings. That should be the primary reason for the lower hardness... 

Fig. 18—High resolution TEM plan-view image of TiN/Si3N4 nanocomposite coating with Si content of 10.8 at. % and hardness of 42 GPa. The coating was deposited on NaCI substrate for about 50 nm thick and then was floated off onto a mesh. The crystallites were confirmed to be TIN by the interplanar distance of 0.21 nm, which is the TIN (200) interplanar distance. The gain size of the TiN crystallites is less than 5 nm.

Fig. 17—XPS spectrum of Si 2p peak for the TiN/Si3N4 nanocomposite coating with the optimum Si content of 10.8 at. % and the maximum hardness of 47.1 GPa.

Veprek et al. [120,121,144] present the explanation of the superhardness for the nanocomposite coating on the basis of the absence of dislocation activity in a few-nanometre-... 

Fig. 22—Friction coefficients between WC ball and TiN/Si3N4 nanocomposite coatings as function of the Si content. The coatings were deposited by reactive magnetron sputtering. The friction coefficients of the TiN/Si3N4 coatings were obtained under the load of 20 N. In the case of the TiN coating and the Si3N4 coating, the load is 5 N, because the two coatings will fail and peel off from the substrate under the load of 20 N.

Fig. 23—The cutting life of the uncoated drill and the drills deposited with TiN coating and TiN/Si3N4 nanocomposite coatings drilling holes on quenched AISI 420 stainless steel. The coatings were deposited by reactive magnetron sputtering.

Holubar, P., Jilek, M., and Sima, M., "Present and Possible Future Applications of Superhard Nanocomposite Coatings, Surf. Coat. Technol,Vol. 133/134,2000,pp. 145-151. 

Voevodin, A. A., Walck, S. D., andZabinski, J. S., Architecture of Multilayer Nanocomposite Coatings with Super-Hard Diamond-Like Carhon Layers for Wear Protechtion at High Contact Load, Wear, Vol. 203-204,1997, pp. 516-527. 

Sellinger, A., Weiss, P. M., Nguyen, A., Lu, Y., Assink, R. A., Gong, W., and Brinker, C. J., Continuous, self-assembly of organic-inorganic nanocomposite coatings that mimic nature. Nature 394,256 (1998). 

FIGURE 8.8 Rate of heat release curves of PU-nanocomposite coatings on PET knitted fabrics at 35kW/m2. (From Devaux, E. et al., Fire Mater., 26, 149, 2002. With permission.)... 

Nanocomposite coatings - nanoparticles giving improved properties compared to microparticles e.g. thermal and electrical conductivity, transparency, uniformity, low friction. 

Some applications are at a fundamental research stage with associated higher risk, i.e. electroless coating, semiconductors, anodising, nanocomposite coatings. 

A. Sellinger, P.M. Weiss, A. Nguyen, Y. Lu, R.A. Assink, W. Gong and C.J. Brinker, Continuous Self-Assembly of Organic-Inorganic Nanocomposite Coatings that Mimic Nacre , Nature, 394 256-60 (1998). 

Fig. 21. Scratch resistance of the nanocomposite coating depending on the thickness in comparison to a conventional Ormocer coating, ref. [22]...

Fig. 23. Comparison of several coatings used on CR eye glass lenses by the tumble test and structural model of the nanocomposite coating...

Gao Y, Ma SL, Xue KW (2007) Effect of carbon content and annealing temperature on the microstructure and hardness of super hard Ti-Si-C-N nanocomposite coatings. Surf Coat Technol 201 5240—5243... 

Davis AG, van Breda JH, Moretto P, Ordelman J (1995) Development of TiN nanocomposite coatings for wear resistance. JdePhysquelV 5 C5-831-840... 

Thiemig, D. and Bund, A., Characterization of electrodeposited Ni-TiO, nanocomposite coatings. Surf. Coat. Technol., 202, 2976, 2008. 

Zhang, Z. et al.. Electrodeposition of Ni-SiC nanocomposite coatings based on the surface charge determination of SiC nanoparticles. Bull. Electrochem., 22, 189, 2006. 

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