Other Coating Processes

2Mg + Si02 2MgO 2Mg + 2Si02 MgSi04 + Si 2Mg + 3S1O4 2MgSi03 + Si 

Improved bonding at the interface can be achieved by the deposition of pyrolytic carbon directly onto the carbon fiber [58] and poor adhesion to P-100 fiber and other high modulus fibers can be improved by an intermediate coat of amorphous carbon [59]. 

Zr02 can be applied by dipping the fiber in a solution of ZrOCb, drying at 80°C and heating at 330°C [61]. 

Vacuum deposition has been tried, but due to the problem of shadowing, it is essential to open out the tow as a preliminary step, therefore, it has not proved successful. 

Coating by thermal decomposition of organometallic compounds has been tried by Harwell, who have used tri-isobutyl aluminum [62]. 

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Organic and inorganic paint systems are widely used to protect and enhance appearance because they are often economic and always flexible in use. In many industries paint is chosen when other coating processes are technically impossible or uneconomic. Because it is so often used upon subjects which are difficult to coat, sensible design detailing becomes even more important. 

CVD is a relatively newcomer in the area of corrosion protection but is making rapid strides and may soon become a serious competitor to PVD and other coating processes. 

Chemical vapor deposition competes directly with other coating processes which, in many cases, are more suitable for the application under consideration. These competing processes comprise the physical vapor deposition (PVD) processes of evaporation, sputtering, and ion plating, as well as the molten-material process of thermal spray and the liquid-phase process of solgel. A short description of each process follows. For greater detail, the listed references should be consulted. 

Other coating processes involving fluoridated apatite have been investigated to improve the long-term adhesion and promote osteointegration of cementless titanium-based metal implants pulsed laser deposition, electron beam deposition and ion beam sputter deposition techniques, and sol-gel methods, for example. They lead to fluor-containing calcium phosphates (apatites in most cases) with different compositions and crystallinity states. 

Zinc electroplated onto steel gives a bright and smooth finish. It is used for decorative effect and to protect delicate objects where rough or uneven finishes cannot be tolerated (in instrument parts) and for articles that cannot withstand the pretreatment or temperatures required in the other coating processes. Electroplated zinc is also very ductile, and the process is widely... 

There is an obvious need to also investigate other coating processes for production of crack-ffee, adherent coatings with the desired minimum Al-content. Fig. 6-19 illustrates results for coatings applied by electrospark-deposition after exposure to a sulfidizing gas mixture (with and without HCl) at 650 °C for 1000 h. These coatings also resulted in a significant improvement in performance compared with the uncoated substrate alloys, type 316 stainless steel and Alloy 800 (Natesan and Johnson, 1995). 

The process is suitable for automation and has economic advantages over other coating processes. 

Don has published more than 100 papers and book chapters on the subject of PVD processing and other coating processes as well as the first technical paper on the PVD process, called Ion Plating. Don is the author of the book Handbook of Physical Vapor Deposition (PVD)... 

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