Sprayed coatings stainless steels

Figure 14.17 Pump casing before (a) being arc sprayed with stainless steel S43000 and top-coated with epoxy (b). (Courtesy of M. Gariepy, WEIR Engineering Services, Montreal, Canada)...

Properties of the deposits Almost any material which can be melted is suitable for plasma spraying, giving a vast range of possible coatings of single or mixed metallic or non-metallic substances. It is often possible to produce types of coatings which are not obtainable in any other way. Typical of the materials which are plasma sprayed are copper, nickel, tantalum, molybdenum. Stellites, alumina, zirconia, tungsten and boron carbides, and stainless steels. 

The Ti02 paint was prepared by the so-called sol-gel method. Alkoxysilanes [(Ri) -Si-(OR2)4 ] were mixed with water for hydrolysis and condensation under certain conditions. Then Ti02 powder was added to the mixture and mixed well to give paint. The paint-coated films were obtained by spraying the paint to stainless steel plates. Thickness of the films was typically 10-30 /im. 

Most of the materials that we have discussed—glass, stainless steel, aluminum, brass, plastics—require no protective coating. Parts made of mild steel, welded angle iron, or pl3Twood should be given a coat of paint, which is most conveniently done using du Pont Krylon acrylic aerosol sprays. Clear polymer varnishes and Teflon coatings can also be applied in spray or liquid form. 

In order to investigate the cathodic photoprotection of the steel from corrosion, stainless steel was coated with Ti02 thin films, applied by a spray pyrolysis [343]. It was concluded that these coatings exhibit both a cathodic... 

Figures 19.9 and 19.10 show two unusual applications of fillers in coatings. Figure 19.9 shows a schematic diagram of the surface of metal (e.g., a pan) on which white-hot particles of stainless steel fibers are sprayed to prepare the surface for a nonstick coating. In the past, these coatings were known to have a limited durability. Durability could be increased by a change to the surface through welding the fibers to the surface.

Figure 5.23 Microplasma-sprayed (MIPS) hydroxyapatite coating on AISI 316L stainless steel, (a) Polished surface and (b) coating cross section (Dey and Mukhopadhyay, 2014). (Images courtesy of Dr Arjun Dey, Indian Space Research Organisation, Bangalore, India.)...

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