High performance aluminum-cerium alloys for high-temperature applications

Light-weight high-temperature alloys are important to the transportation industry where weight, cost, and operating temperature are major factors in the design of energy efficient vehicles. Aluminum alloys fill this gap economically but lack high-temperature mechanical performance. Alloying aluminum with cerium creates a highly castable alloy, compatible with traditional aluminum alloy additions, that exhibits dramatically improved high-temperature performance. These compositions display a room temperature ultimate tensile strength of 400MPa and yield strength of 320 MPa, with 80% mechanical property retention at 240 degrees C. A mechanism is identified that addresses the mechanical property stability of the Al-alloys to at least 300 degrees C and their microstructural stability to above 500 degrees C which may enable applications without the need for heat treatment. Finally, neutron diffraction under load provides insight into the unusual mechanisms driving the mechanical strength.