Abstract: A double-wall airfoil for applications such as the blades and vanes of gas turbine engines. The double-wall comprises an outer airfoil skin and an inner support wall that are metallurgically bonded to one another. The double-wall contains integral channels for passage of cooling air adjacent to the airfoil skin. Airfoil skin may be a metal alloy skin or a microlaminate structure, including microlaminate composite structures. Microlaminate composites typically have a lower density than that of the material used for the airfoil support wall, and a simplified internal geometry which promote weight reductions in the airfoils and increases in engine operating efficiency.

Abstract: An improved method for forming fluid inflatable metal structures is taught. The improvement concerns the patterning of the portion of the structure to be inflated. Patterning is accomplished by first applying a strippable flexible mask coating and then scoring this coating so that a patterned portion may be removed therefrom. The parent portion is the portion of the sheet article to be inflated by subsequent processing. After the patterned portion has been removed, a stop-off is applied to the exposed surface of the first sheet. After the stop-off material has been applied, the remainder of the strippable mask is removed and washed with a detergent to remove the residue from the mask. The sheet having stop-off applied in the pattern to the first sheet is then superposed over a second sheet, and heat and pressure are applied to cause diffusion bonding between the exposed surfaces of the two sheets.

Abstract: An improved method for superplastic forming diffusion bonding includes application of a protective encapsulating coating over the stop-off coating to prevent migration of yttria into regions to be diffusion bond.

Abstract: Titanium niobium aluminide alloys having improved room temperature ductility and fracture toughness are comprised of, in atomic percent, about 18 to 30 percent aluminum, about 18 to 34 percent niobium, about 0.25 to 7 percent vanadium, and the balance substantially titanium.

Abstract: An improved titanium aluminide alloy contains from about 18 to 30 atomic percent aluminum, about 34 to 18 atomic percent niobium, with the balance titanium. In alloys of this invention a substatial portion of the microstructure, comprising at least about 50% of the volume fraction, is an orthorhombic phase.

Abstract: Alpha titanium alloys containing aluminum, hafnium and/or tantalum has been found to have improved creep and tensile strengths as well as oxidation resistance at temperature up to about 700.degree. C. without embrittlement.

Abstract: A cold hearth melting system has confining side wall area made of high thermal conductivity material and has as its bottom a diaphragm containing an orifice through which metal melted in the cold hearth is discharged. The diaphragm is made, at least in the central portion thereof containing the orifice, of material selected from the group consisting of tungsten, an alloy containing tungsten and having a melting point of at least about 3000.degree. C., cemented tungsten carbide and tantalum carbide.

Abstract: A titanium alloy base composition is prepared to contain a finely divided dispersoid of a compound which is stable in the alloy at elevated temperatures. The compound is of a metal and non-metal. The non-metal may be sulfide, oxysulfide or a combination of sulfide and oxysulfide. The compound metal may be at least one metal selected from the group comprising calcium, strontium and a rare earth metal selected from the group consisting of those rare earth metals having a chemical stability greater than that of the corresponding compound of yttrium.

Abstract: A titanium base composition is prepared to contain a finely divided dispersoid of a compound which is stable in the composition at elevated temperatures. The compound is of a metal and a non-metal. The non-metal may be sulfide or oxysulfide or a combination of sulfide and oxysulfide. The compound metal may be at least one metal selected from the group comprising calcium, strontium and a rare earth metal selected from the group consisting of those having a chemical stability greater than that of the corresponding compound of yttrium.