Abstract: In one broad aspect the present invention comprises the steps of providing a titanium-based material preform and superplastically forming the preform to a final helmet shape. In another broad aspect, a first piece of fiber-reinforced titanium matrix composite material is hot isostatically pressed (HIP'ed) to form a side wall section. A second piece of fiber-reinforced titanium matrix composite material is hot pressed to form an upper dome section. The side wall section is then HIP/diffusion bonded to the upper dome section.
Abstract: A method of diffusion bonding copper to titanium alloy employing hot isosic pressure by an inert gas in a sealed chamber. Use of niobium metal as an interfoil between the copper and titanium alloy and the application of the method to the manufacture of a projectile is also disclosed.
March 7, 1989
Date of Patent:
May 29, 1990
The United States of America as represented by the Secretary of the Army
Abstract: An evacuated double wall tubing is shown together with a method for the manufacture of such tubing which includes providing a first pipe of predetermined larger diameter and a second pipe having an O.D. substantially smaller than the I.D. of the first pipe. An evacuation opening is then in the first pipe. The second pipe is inserted inside the first pipe with an annular space therebetween. The pipes are welded together at one end. A stretching tool is secured to the other end of the second pipe after welding. The second pipe is then prestressed mechanically with the stretching tool an amount sufficient to prevent substantial buckling of the second pipe under normal operating conditions of the double wall pipe. The other ends of the first pipe and the prestressed second pipe are welded together, preferably by explosion welding, without the introduction of mechanical spacers between the pipes.
October 31, 1988
Date of Patent:
October 31, 1989
Charles R. Stahl, Michael A. Gibson, Christian W. Knudsen
Abstract: An erosion resistant article such as a turbine blade having, in use, a surface subject to high angle impingement and a surface subject to low angle impingement, said article comprising a substrate defining said surfaces composed of a refractory metal, titanium alloy, refractory alloy, aluminum alloy, superalloy based on Fe, Co or Ni, stainless steel or ceramic composite, and an erosion-resistant coating of zirconium nitride having an averge grain size of not greater than about 3000 Angstroms applied by physical vapor deposition to said surfaces, said zirconium nitride coating preferably having a ratio of the erosion rate at an impingement angle of 90.degree. to the erosion rate at an impingement angle of 20.degree. of not greater than about 1.5 and having an erosion rate at all impingement angles from 20.degree. to 90.degree. at least about two times less than that of said substrate at the same impingement angles.
Abstract: Ti or a high-Ti alloy is melted in a container composed of high-purity CaO materials on its inner sides. The materials are composed of not less than 99% by weight of CaO, not more than 0.1% by weight of SiO.sub.2, not more than 0.02% by weight of Fe.sub.2 O.sub.3, and not more than 0.5% by weight in total of other metal oxides under a non-oxidizing atmosphere.CaO refractories for use in the melting of Ti or a high-Ti alloy contains not less than 99% by weight of CaO, not more than 0.1% by weight of SiO.sub.2, 0.02% by weight of Fe.sub.2 O.sub.3, and not more than 0.5% by weight of other metal oxides.
Abstract: A method of forming a composite structure having precision surface openings, such as an air foil through which air can be drawn in for boundary layer control. A metallic face sheet is bonded to a base member that is formed with elongate channels which are to serve as air plenums. A protective metal strip is inserted into each channel, and a high velocity water jet is directed against the face sheet at the area of each channel to form a through slot opening. The protective strip protects the base material from the inpact of the water after it passes through the slot being formed.
Abstract: A process of precision forging of titanium or a titanium alloy in which the forging stock and a segmented die are first heated to forging temperature while separated, and are then assembled together and heated again to that temperature, with the stock being covered by a protective coating preferably containing glass grit, and the die sections being coated with lubricant. The heated die and contained heated forging stock are then inserted in a heated holder and the stock subjected to forging force, to partially but not completely deform the stock to the shape of the die cavity, following which the die and stock are separated and the stock allowed to cool, flashing is removed from the stock, the die is cleaned, the die and stock are recoated and then reheated separately and then together, and the stock is forged again to assume more closely the shape of the die cavity.
Abstract: A bimetallic tube comprising a copper-base alloy and a reactive metal such as titanium, is produced by assembling concentrically a tubular member of each of such materials and interposing a layer of copper, nickel or silver between them, forming a bond between the reactive metal and the copper, nickel or silver and extruding the assembly. The bimetallic tube is useful for heat exchange purposes when corrosive fluids are involved and has better heat transfer properties than an all-reactive metal tube.
Abstract: In regard to sheet metals of inferior formability as typified by titanium alloys, each end face of a blank is covered with a cover plate of a metal which surpasses the blank material in formability, and the covered blank is subjected to a usual shaping operation in which the steps of heating the blank and pressing the heated blank are cycled a plurality of times, so that the blank can be protected against contamination attributable to exposure of the hot blank to the atmosphere and hence saved from having a large margin in the thickness thereof. A lubricant layer is preferably formed between the blank and each cover plate for a further improvement on the formability.
Abstract: Apparatus and related process steps are disclosed for manufacturing titanium alloy sheet metal parts over a die form using radiant heating, particular mechanical motions, and differential fluid pressures in specific sequences of operations. The resulting parts have configurations with substantial depths and are produced both at accelerated rates and with reduced alloy contamination in comparison to known titanium sheet metal forming practices.
Abstract: Production of tapered titanium alloy tube performed by subjecting uniformly dimensioned tube to multiple swaging steps interspersed with vacuum annealing, heat hardening in the presence of atmospheric gases producing high yield strength in the final product.