Experimental Analysis of Performance and Emission Characteristics of Tungsten Carbide Coated Piston

Heat energy produced in the combustion chamber of an IC engine cannot be completely converted into useful work due to heat transfer losses. This leads to a fall in the performance of the engine. To overcome this, pistons have been coated with different materials like molybdenum disulphide, chromium nitrides and other materials. These thermal barrier coatings have improved the performance of the engine by preventing heat loss. In this experiment, the performance and emission characteristics of a tungsten carbide coated piston was investigated. WC was coated on the piston surface by EB-PVD Process. The WC coated piston was tested in an MK20 engine using an eddy current dynamometer. The performance of uncoated and WC coated pistons were compared and analyzed. An increase in combustion chamber temperature was obtained while using WC coated piston, which was observed by increased exhaust gas temperature. WC coated piston shows 9.89% increase in BTE than uncoated pistons, simultaneously the fuel consumption decreased, and the emissions of WC coated piston were more controlled than the uncoated piston except for oxides of nitrogen. Reduction of HC upto 10.95% and 46.9% of CO were observed with 26.9% increase in NOx at full load condition while using coated piston.