Thermal barrier Analysis in Diesel

The specific outputs of some diesel engine applications have produced thermal loadings in excess of the strength of typical aluminium piston alloys. Functionally graded coatings are used to increase performances of high temperature components in diesel engines. Thermal barrier coating are being evaluated to return the components durability to acceptable levels as well as providing a means of lowering heat rejection. This paper discusses the use of a finite element model to analyze these thermal barrier coating systems, including the impact of material properties, coating thickness, residual stress and boundary conditions. These coatings consist of a transition from the metallic bond layer to cermet and from cermet to the ceramic layer. Thermal analyses were employed to deposit metallic, cermet and ceramic powders such as NiCrAl, NiCrAl+MgZrO3 and MgZrO3 on the substrate. The numerical results of AlSi and steel pistons are compared with each other. It was shown that the maximum surface temperature of the functional graded coating AlSi alloy and steel pistons was increased by 28% and 17%, respectively. In this study, thermal behavior of functional graded coatings on AlSi and steel piston materials was investigated by means of using a commercial code, namely ANSYS