C-C Pistons for high temperature engines

The thrust to develop cleaner burning combusion systems with reduced levels of emissions (NOx and SOx) has led to a renewed interest in the exploration for the use of advanced materials in components such as pistons. Other driving forces are fuel economy, and NVH (noise vibration, and harshness). The first two (emissions and fuel economy) are government mandated while the NVH is a mandate of the marketplace. All of these driving forces and goals will ultimately affect the piston design used in the engine In gasoline engines, as well as natural gas engines, hypereutectic aluminum silicon (>12%) alloyw are normally used due to their excellent wear resistance. However, they have limitations in the overall temperature to which they can be exposed thus resulting in a limitation in the combustion temperatures in the engine. If higher temperatures are desired in future engines, advanced materials will be needed to extend these limits. Carbon-Carbon materials were developed for the aerospace industry and have historically been ignored for large volume commercial applications due to their high costs. However, in the last 5 years, the advent of a number of new processing routes to form carbon fibers has reduced the prices of production significantly and this ha resulted in the engineering viability of commercial products using these materials. C-C composites also exhibit superior mechanical properties at elevated temperatures. In this Phase I effort, MMI will demonstrate the feasibility of producing C-C pistons by developing all the manufacturing sequences necessary for commercial production. This will allow production of pistons for engine bed testing in Phase II.