Experimental Investigation of Thermal Barrier (۸YSZ-MGO-TIO۲) Coated Piston used in Diesel Engine

A single cylinder diesel engine was tested under different loading conditions with its piston crown coated with the Thermal Barrier Coating (TBC). The main objective of this work is to investigate the effect of the TBC on performance and emission characteristics in the diesel engine. The top surface of the piston was coated with ۱۰۰ µm thick NiCrAl as lining layer by plasma spray method. A mixture of ۸۸% Yttria stabilized Zirconia, ۴% MgO and ۸% TiO۲ of ۱۵۰ µm thick were coated over the lining layer. Exhaust emission (HC, NOx, CO and CO۲) parameters were investigated using AVL exhaust gas analyzer. The results showed that the brake thermal efficiency was increased by ۱۰% and brake specific fuel consumption was decreased by ۹.۸% for coated piston in comparison with the uncoated piston engine. It was also observed that, smoke, CO and HC emissions were decreased in the TBC engine as compared with the baseline engine. In addition carbon di oxide (CO۲) and nitrogen oxide (NOx) emissions were partially increased.

Keywords:

Yttria stabilized zirconia , Thermal barrier coating , Diesel engine , Plasma spray , Emission , Piston crown