Thermal Analysis of Mullite Coated Piston Used in a Diesel Engine

Abstract

Due to special working conditions, diesel engines often need to run stably for a long time at high power operating conditions. As the core of diesel engine moving parts, the piston needs to be exposed to high temperature for a long time. Based on the problem of excessive piston temperature at the maximum power point of a certain type of diesel engine, this paper discussed the protective effect of using different thicknesses of Mullite thermal barrier coating on the top surface of the piston, by using the method of hardness plug temperature measurement and three-dimensional simulation. When the thickness of the ceramic coating was increased from 0.2 to 0.7 mm, the maximum temperature of the piston seat decreased from 358.6 to 338.9 °C. This showed that the use of Mullite thermal barrier coating could reduce the working temperature of the aluminum alloy piston at the maximum load operating point, and greatly improve the reliability of engine components.