Optimization of Dual Coating Using Electroless Ni‐P‐Nano‐TiO 2 and Plasma Yttria‐Stabilized Zirconia on Piston Crown and Cylinder Liner in CI Engine

Most of the automobile engine components are made up of cast iron because of its low cost, damping characteristics, castability, and commercial considerations. In modern days, the blended biodiesels are introduced into the CI engine to reduce the usage of petroleum fuels. The following problems are identified in utilizing the biodiesels, they are lower efficiency, power, wear in the engine cylinder and piston crowns, more emission from the exhaust, and performance. To overcome the wear problem in cylinder liner and piston crown, the dual coating is developed using electroless coating and plasma spray coating, and this deposit acts as a thermal barrier to the engine. The electroless Ni-P-TiO2 composite coating process parameters are optimized using the Taguchi technique with multiresponse grey relational analysis. The plasma spray coating is developed over electroless Ni-P coating using Yttria-stabilized Zirconia for the total thickness of 2 mm. The coated components are installed in the CI engine for further testing and analysis. The morphology of the coated surfaces is tested using the scanning electron microscope. The optimization process used to improve the Ni-P coating thickness, surface roughness, and thermal resistance of the engine components. Also, the performance and emissions in the engine are reduced significantly. The emission from the CI engine such as NOx, COx, and HC are reduced significantly. The emissions of CI engine such as NOx, CO2, CO, and HC of the noncoated engine shows higher, and EPSCE engine condition shows less pollution. The percentage of improvement in terms of emissions are 27%, 70%, 6.4%, and 21%, respectively. The performance is improved to 3% and 27.8%, respectively, for specific fuel consumption and brake thermal efficiency.