Abstract: A class of lightweight structural members, characterized by lighter weight and greater resistance to buckling under axial compressive loading, as compared to conventional structural members, is described. The lightweight structural members typically comprise a thin tubular member filled with a metallic foam material. The foam material preferably comprises particulate matter comprised of agglomerated fly ash material, and, preferably, gaseous material in pores within the foam material. In an alternate configuration, the lightweight structural member comprises two tubular members, one nested inside the other, wherein the annular volume between the tubular members is filled with metallic foam material. A method for manufacturing the structural members is also described.

Abstract: A turbine blade comprises an airfoil/shank having a shank region and an airfoil region extending upwardly therefrom and two dovetail/platforms bonded thereto. The first dovetail/platform has a first dovetail region bonded to a first side of the shank region of the airfoil/shank, with a first platform region extending outwardly from the first dovetail region. The second dovetail/platform has a second dovetail region bonded to a second side of the shank region of the airfoil/shank and a second platform region extending outwardly from the second dovetail region in a direction generally opposite to that of the first platform region.

Abstract: A dual alloy disk made from a rim alloy having high stress rupture and creep resistance as well as good hold time fatigue crack resistance and a hub alloy having high tensile strength and good low cycle fatigue crack resistance is described. The dual alloy disk is designed for use as a disk in gas turbine engines operating as high as 1500.degree. F. The hub and rim are joined together at a substantially defect-free joint to form a turbine disk having improved properties in both the hub and rim regions.

Abstract: Two pieces of metal are bonded together at a surface by placing the two pieces into contact at the surface and forging the two pieces in a die which causes substantial displacement of the metal originally at the surface in a direction parallel to and outwardly from the edges of the surface. In this way, many of the defects which are potentially present at the original surface are displaced with moving metal away from the original contact between the two pieces of metal into sacrificial ribs and the remaining defects are exposed to significant strain. A portion of the displaced metal which contains many of the defects and which forms the sacrificial ribs is removed from the resulting bonded work piece as the sacrificial ribs are removed from the work piece. The result is a bond with superior properties and with a bond surface which can be located very precisely.

Abstract: An article of manufacture having at least a first and a second part, each part having different mechanical properties, compositions, microstructures or combinations thereof, being joined together using a forging process to yield a substantially defect-free joint region. The article in the form of a turbine disk is particularly suited for use in a gas turbine engine in which the hub or inner portion must be resistant to low cycle fatigue and have high strength, while the rim or outer portion must be resistant to stress rupture failure and creep failure.