Characterization of Near Net-Shape Castable Rare Earth Modified Aluminum Alloys for High Temperature Application

Abstract

The modern family of aluminum alloys has a broad range of applications. However, there are currently few aluminum alloys capable of operating at elevated temperatures while maintaining mechanical properties necessary for high performance automotive and aerospace applications. The high temperature phase equilibrium of Al-REE-X (REE-Rare earth elements and X-traditional alloying elements) is not well understood yet this class of materials shows promise as a lightweight material for stiffness-driven high temperature applications. To date, we have determined RE alloys of Al to be castable across a broad range of temperatures and compositions. In addition, room temperature physical properties of Al-RE alloys appear to be in line with existing aluminum alloys with superior microstructural stability and associated properties at temperatures exceeding 150 °C. The CALPHAD work, microstructure, and compositional data are presented for representative example of Al-RE alloys at room and elevated temperatures.