초록

Aluminium alloy pistons used in I.C. engines are exposed to high temperature and may contribute to high thermal residualstresses on the piston crowns. The pistons operate ineffectively due to lack of appropriate coatings on pistons. The applicationof Thermal Barrier Coatings (TBC) on the components of IC engine reduces the combustion chamber heat rejectionsignificantly. The current work is put to determine the temperature distribution of ceramic coated piston using finite elementsoftware and reduce the effect of thermal stress. Prior to coating on piston crowns, La2O3 is mixed at 10%, 20% and 30%proportions with Mullite and plasma spray deposited on A356 aluminium alloy substrate with base coat of NiCr fordetermination of best performing composition. The experimental test results from tensile test performed as per ISO – 1608and adhesive test performed as per ASTM C633-79 confirms that 10% La2O3 mixed with mullite produces improvedperformance of 10% and 27% improved respectively. In addition, the temperature distribution study performed using Ansys11 software for 10% La2O3 mixed with mullite also produced 12% less thermal stresses during combustion operation incomparison with uncoated pistons. Mullite - La2O3 TBC coatings support in maintaining the combustion temperature andsupports in reduction of HC emission during operation. The reduction in thermal stresses of engine components significantlyimproving the performance and its service life.

키워드

Coated Piston, Mullite, Thermal Barrier Coatings, Plasma Spraying, FEA Analysis.

참고문헌(7)open

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