Development of Endurable Thermal Barrier Coatings for Diesel Engine Specific Heat Reduction

This program proposes to develop advanced thermal barrier coatings and an advanced thermal insulating exhaust port runner to reduce high power density diesel engine heat rejection. Analytical Engineering, Inc. along with APS-Materials, Inc. and Ceradyne Thermal Materials will develop and bench test thermal barrier coatings that will address the important issues of thermal insulating effectiveness and durability. In addition, an advanced thermal insulation exhaust port ceramic monolith with compliant layer will be developed to accommodate the severe thermal shock and shrinkage that occurs during the casting process. Thermal barrier coatings will be developed to address the issues of radiation translucence and convective heat exchange between the coating surface porosity and in-cylinder gases. To maximize insulating effectiveness it is proposed that the thermal barrier coating combustion chamber surface porosity be closed off and sealed with materials that will either block or reflect thermal radiation. To maximize coating durability the plasma sprayed coating substrate will be engineered for optimum stress control by means of graded coatings, optimized grain size, controlled variable density distribution, micro-crack control, post-densification etc.