Be-Al alloys are unique, light weight, in-situ composite alloys that combine high specific stiffness and substantial strength with good ductility and toughness. This conibination of properties makes these alloys attractive for many high performance aerospace applications. Nuclear Metals, Inc. (NMI) has developed a new family of castable Be-Al alloys and the manufacturing processes necessary to produce high quality investment cast components. However, this development has focused on producing large, complex, thin walled castings for secondary support structures. The majority of part designs in propulsion systems require castings with internal passages, thick sections, and large thick to thin transitions. New processing techniques will need to be developed to produce high quality castings with this combination of features. NMI will team with Allison Engine Company (AEC) in this program to demonstrate the feasibility and benefits of using Be-Al alloys to produce cast components for helicopter propulsion system applications. A five task effort is proposed that will: (1) determine key mechanical and physical properties required for specific propulsion system applications, and the suitability and benefits of Be-Al for these applications; (2) identify critical manufacturing technology; and (3) demonstrate feasibility of the critical manufacturing technology. The development of this technology will lead to a variety of commercial and defense aerospace applications. Applications envisioned include the T800-LHT-801 engine for the RAH-66 Comanche, directly addressed by the proposed research; the ASTOVL lift fan program, in which several weight critical components have been identified; and the T406 engine, which has 2 commercial derivatives.
Keywords: Beryllium Aluminum Beralcastr Propulsion Systems Investment Casting Metal Matrix Composites
