Plasma sprayed coatings, zinc

On the other hand, industrial equipment such as regasification plants for liquid natural gas operating by seawater spraying and located in closed and polluted sites are usually protected by thermal or plasma projection coatings with aluminium-zinc alloys, and are additionally protected with specific paints. 

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. 

Another way to simulate alcladding is to apply a coating of an anodic alloy to an aluminum surface by thermal spray techniques, such as flame or plasma spray. These coatings act in the same way as the clad-(fing layer on an alclad product and corrode sacrifi-cially to protect the core alloy (Ref 11,12). Similarly, anodic coatings (zinc, pure aluminum or a more anodic aluminum alloy) can be applied by hot dipping or vapor deposition. 

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