Experimental investigation on thermal cycling behavior and performance characteristics of thermal barrier coating in dici engine

Abstract

newline newlineIn recent decades, several research works are being carried out in automotive industry to reduce fuel consumption and exhaust emission. Depletion of fossil fuels, increase in fuel prices, environmental pollution and global warming has spearheaded the researchers to take necessary steps to reduce fuel consumption. The most efficient method to reduce the fuel consumption and exhaust emission is to develop more efficient combustion engines. The CI engine rejects about 65 to 70% of the heat energy of fuel as a waste (30-35% of the heat energy to the in-cylinder heat transfer and 30-35% of the heat energy to the exhaust gas), and the remaining 30 to 35% of the heat energy is converted to useful work. Theoretically, thermal efficiency will increase, when the heat rejection is reduced. To improve engine performance, fuel energy must be converted to mechanical energy at the most possible rate. Thermal Barrier Coating (TBCs) in CI engine components reduce heat loss and enhance better thermal efficiency. It also improves engine components durability. In order to achieve better combustion, higher thermal efficiency, lower emission and good fatigue life time, TBCs are being applied over the engine combustion chamber components. In this research work, 8% yttria stabilized zirconia (8YSZ), titanium oxide/yttria stabilized zirconia (20%TiO2/80%8YSZ), aluminium oxide/yttria stabilized zirconia (20%Al2O3/80%8YSZ) and ceria/yttria stabilized zirconia (20%CeO2/80%8YSZ) were coated on aluminium alloy (Al-13%Si) substrate by using atmospheric plasma spray (APS) technique. CoNiCrAlY was used as bond coat material. Thermal cycle test of TBC coated samples were conducted at 800and#730;C in electric furnace and its thermal cycling behavior were studied. newline newline