Thermal barrier coatings were originally developed for air craft engine applications in 1940 only recently have they been modified and tested for use in diesel engines This result in reduction of metal temperature of the component up to 170 deg C
Two coating techniques are used Surfacepreparation and Thermal spraying
Coating of a material on a substance is made to serve in the specific environment It is possible only if the coating is adherent to the surface of the component The coating flakes off or leaves the surface, the entire effort will go waste The adhesion and other properties of the coating mainly depend on the surface condition of the substrate
Cleaning To remove foreign materials like grease, scale, rust, dirt etc from the surface of a component roughness and rough enough to make the mechanical bonding, adequate
This technique involves feeding of a metallic wire into a flame produced by combustion of fuel gas This flame melts the wire and surrounding stream of compressed air spray the molten metal onto the substrate The temperature produced in this process is about 2600-31000C The wire has melting point about 2500 deg c
The plasma spraying uses coating materials in the form of powders, which are melted with plasma heat source The primary arc bas, usually argon or nitrogen are ionized by the electrical discharge from a high frequency arc starter the plasma can conduct currents as high as 2000A direct current, with voltage potentials ranging from approximately 30 to 80V
Prolonged exposure to a higher temperature oxidizing environment may lead to coating failure thermal expansion mismatch between the ceramic and metallic layers and failure appears to be strongly influenced by bond coat oxidation
: ENGINE: A single cylinder water cooled Kirloskar engine is used for our analysis. The water at room temperature is allowed to pass through the water jacket in the engine. A The engine is coupled with the mechanical rope dynamometer for leading. The specification of the engine is given as follows.
Engine name Kirloskar engineType Single cylinder vertical diesel engine.Rated rpm 1500Bore 79.9Stroke 110Capacity 553 ccCompression 16.5:1Ignition CIPower 5 Hp
without ceramic coating, the maximum brake thermal efficiency is 16% with ceramic coating, the maximum brake thermal efficiency is 20.4%.
Ceramic thermal barrier coating is a problem solving technology which contributes to almost every branch of engineering. thermal barrier coating allows engineering to improve product and performance, reduce maintenance time, cost, save energy and reduce production cost.