2. 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
3. Two coating techniques are used
Surfacepreparation and
Thermal spraying
4. 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
5. 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
7. 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
8. 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
9. 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
10. :
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.
11. Engine name Kirloskar engine
Type Single cylinder vertical diesel engine.
Rated rpm 1500
Bore 79.9
Stroke 110
Capacity 553 cc
Compression 16.5:1
Ignition CI
Power 5 Hp
12. without ceramic coating, the maximum brake
thermal efficiency is 16%
with ceramic coating, the maximum brake
thermal efficiency is 20.4%.
14. 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.