Thermal spray coatings zinc, applications

Guide for Selecting One-Coat Preconstruction or Prefabrication Painting Systems Interim Specification for the Application of Thermal Spray Coatings (Metallizing) of Aluminum, Zinc, and Their Alloys and Composites for the Corrosion Protection of Steel Latex Painting System for Industrial and Marine Atmospheres, Performance-Based... 

This is the case, for instance, for K2Sip6 which in an aluminothermic reaction provides in situ the Al-Si clad (molten fiUer metal) normally used for controlled atmosphere brazing (CAB) of aluminium. In the case of zinc, the primary objective is not only to form a clad but to obtain a homogeneous diffusion layer into the aluminium, which is needed for some applications and which would have to be otherwise applied by costly intensive methods like electrochemical galvanization, plasma coating or thermal spray coating. 

Protecting a surface from corrosion by coating can be accomplished by a number of well-established processes which include paints, metal plating (with zinc or cadmium), diffusion, thermal spraying, and, more recently, vapor deposition processes. Of these physical vapor deposition (PVD) is used extensively in corrosion protection. Typical applications are ... 

Thermally sprayed soluble coatings of zinc or aluminium (or their aUoys) are also used. Practical experience exists in the USA, among others, on bridges. Another sacrificial system is based on a zinc foil attached to the concrete surface via an ion-conducting gel adhesive [52-54]. Sacrificial CP systems have obvious advantages of simplicity and ease of application the main questions concern their effective service life. 

The addition of aluminum to zinc is beneficial in improving its corrosion resistance and has resulted in development of coatings with aluminum contents between 5 and 55 %, like Galfan and Galvalume for hot dip and Zn-15 % Al alloy for thermal spray applications. In these coatings, the initial... 

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