Research on Moderate Thermal Insulation of Highly Strengthened Diesel Engine piston

Abstract

Thermal insulation coating at the top surfaces of the piston can reduce the thermal loads and improve its service life. The AlCrN coating was used for the heat insulation of a highly strengthened diesel engine aluminum alloy piston and the finite element model of piston was established. The influences of the coating on the piston temperature field and thermal stress field were analyzed and compared. Results show that the AlCrN coating effectively decreases the working temperature of the piston head and the first ring groove, and those temperatures decrease with the increase of the coating thickness. When the coating thickness is 60 m, the maximum temperature of the substrate of the piston and the average temperature of the first ring groove decrease 18.1% and 14.5%, respectively. The thermal stress of the upper portion of the back surface, pin hole edge and the first ring decreased respectively 22.8%, 12.6% and 13.8%.

Keywords

• highly strengthened piston
• thermal insulation coating
• finite element method
• thermal analysis