Steadily increasing US fuel economy standards for vehicles have created an urgent societal demand for higher-temperature-capability aluminum alloys. These new alloys will have a higher-temperature operation limit and will enable higher-efficiency passenger car engine designs. For the common precipitation-hardened Al-Cu alloys strengthened by Al2Cu intermetallic precipitates, the upper limit of use is related to the ability to suppress transformation of the ?′ phase to the thermodynamically stable ? phase.
In this talk, the speaker will describe a new approach to substantially increase the thermal stability of ?′ precipitates in Al-Cu alloys through interfacial solute segregation. Emphasis will be given to demonstrating the use of atomic-scale characterization and computational tools that allowed the development of alloys for higher-temperature engines. A summary and time line of activities in the area of lightweight high-temperature alloy development for automotive engines will be presented. Current activities will be discussed, including the design of elevated-temperature lightweight alloys for additive processing, and prospects in that area of alloy development will be outlined.
About the Speaker: Amit Shyam is a Senior R&D Staff Scientist in the Alloy Behavior and Design Group that is within the ORNL Materials Science and Technology Division. He joined ORNL in November 2004 as a postdoctoral researcher. His current research interests include design of lightweight alloys for structural applications.