Why Thermal Sprayed Coating give batter performance compare to normal protective coating in CUI especially in extreme fluctuation temperature?

thermal spray coating is a coating produced by a process in which molten particles are applied by impact onto a substance. it has been part of NACE SPO-198-2010 control of corrosion under insulation and fire proofing.

TSC is an advanced coating system and show promising performance in harsh environment. TSC provide a monolithic barrier to water , chemical , UV rays and heat transfer.

thermal spray materials like molybdenum, tungsten and aluminum / metal composites produce so called self bonding coating . theses materials have comparatively high bond strengths ( increased metallurgical or diffusion bonding ).

molybdenum and other refractory metals have high melting point thus the interaction between substrate and coating particles will be increased due to the higher temperatures involved and longer cooling cycles . aluminum /metal composites produce increased levels of exothermic reaction due to reaction of aluminum with metals .the increased action increase degree of diffusion bonding

TSC fall into three main groups ( anodic coatings - cathodic coatings - neutral coating

anodic coatings such as thermal spray aluminum(TSA) is a huge anode , due to this, and the inert, firmly adhered oxide layer that forms on the surface and in any pores in the TSA. the coating is considered first and foremost a barrier to electrolytes thus removing one part of the corrosion cell. the entire carbon steel surface coated is now cathodic to the entire TSA coating therefore removing the possibility of carbon steel corrosion cells until the TSA is all consumed .  

TSC yield low corrosion rate of 0.05mm / year especially at high temp 80 C where usually normal coating fails