| abstract |
A channelless steel piston (10, 1) is provided, designed to improve the thermal efficiency, fuel consumption and performance of the engine. The piston (10,1) includes a steel body portion and a thermal barrier (12,32) applied to the upper combustion surface (16) and/or the annular band (32) to reduce heat transfer from the combustion chamber to the body portion. The thermal conductivity of the thermal barrier layers (12, 32) is lower than the thermal conductivity of the steel body portion. Thermal barrier layers (12, 32) typically include ceramic materials such as ceria, ceria-stabilized zirconia, and/or a mixture of ceria-stabilized zirconia and yttria-stabilized zirconia in amounts based on 90 to 100% by weight of the total weight of the ceramic material. The thermal barrier layer (12, 32) may also have a gradient structure that gradually transitions from 100% by weight of metallic bonding material to 100% by weight of ceramic material. |