Thermal Barrier Coatings for Diesel Engines - Past, Present, and Future

The use of thermal barrier coatings (TBCs) in reciprocating engines has been pursued for more than 40 years. While their introduction can be traced to reducing cooling in military vehicles, contemporary research focuses on improving fuel economy, reducing emissions, and enabling alternative fuels. Despite the potential for great improvements in these systems, TBCs have seen little commercial implementation, in part due to many complexities that develop as coatings are introduced in the system. The connection between process, coating properties, and engine performance is highlighted in this work through examples of coatings engineered for various reciprocating engines. Lessons learned through engine tests reveal the requirements for ideal manufacturing strategies, coating properties, metrology necessary for success in this application.