Abstract: A method and apparatus for fixturing an airfoil stub during linear friction welding are described. Critical clamping support structures are manufactured by a direct digital manufacturing process such as direct metal laser sintering to minimize time and expense of the process.

Abstract: A method of processing steel includes carburizing a martensitic stainless steel work piece to produce a carburized case by utilizing in combination, (i) a composition of the martensitic stainless steel work piece, (ii) a preselected carbon concentration in the carburized case, and (iii) a preselected grain size of the martensitic stainless steel work piece such that the carburized case predominately forms carbides of composition M6C, M2C, M23C6 or combinations thereof. The martensitic stainless steel work piece is then heated to substantially solution the metal carbides. The work piece is then quenched at a cooling rate that is sufficient to avoid substantial precipitation of any carbides during cool down to the martensite start temperature, then given a low temperature temper. In so doing, the carburized case hardened martensitic stainless steel will have balanced mechanical, tribological and corrosion resistance properties for high performance bearing and gear components.

Abstract: A device and method for locally heat treating at least one airfoil in an integrally bladed rotor device. A pair of IR heat sources are positioned to direct IR heat rays in the direction where local heat treatment is required. A pair of parabolic mirrors are positioned to direct the IR heat rays on to the metal component. The heat treating is useful after welding the airfoil on to the rotor device.

Abstract: A method of processing steel includes carburizing a martensitic stainless steel work piece to produce a carburized case by utilizing in combination, (i) a composition of the martensitic stainless steel work piece, (ii) a preselected carbon concentration in the carburized case, and (iii) a preselected grain size of the martensitic stainless steel work piece such that the carburized case predominately forms carbides of composition M6C, M2C, M23C6 or combinations thereof. The martensitic stainless steel work piece is then heated to substantially solution the metal carbides. The work piece is then quenched at a cooling rate that is sufficient to avoid substantial precipitation of any carbides during cool down to the martensite start temperature, then given a low temperature temper. In so doing, the carburized case hardened martensitic stainless steel will have balanced mechanical, tribological and corrosion resistance properties for high performance bearing and gear components.

Abstract: A method is disclosed for welding a first metal to a Ti-6246 alloy airfoil. The method consists of depositing weld metal by fusion welding and reshaping the airfoil to predetermined dimensions. A post weld heat treatment is applied to relieve residual stresses. Surface treatment such as laser shock peening introduces residual surface compressive stresses to enhance the mechanical integrity of the airfoil.

Abstract: A method of processing steel includes carburizing a martensitic stainless steel work piece to produce a carburized case by utilizing in combination, (i) a composition of the martensitic stainless steel work piece, (ii) a preselected carbon concentration in the carburized case, and (iii) a preselected grain size of the martensitic stainless steel work piece such that the carburized case predominately forms carbides of composition M6C, M2C, M23C6 or combinations thereof. The martensitic stainless steel work piece is then heated to substantially solution the metal carbides. The work piece is then quenched at a cooling rate that is sufficient to avoid substantial precipitation of any carbides during cool down to the martensite start temperature, then given a low temperature temper. In so doing, the carburized case hardened martensitic stainless steel will have balanced mechanical, tribological and corrosion resistance properties for high performance bearing and gear components.

Abstract: A method and apparatus for fixturing an airfoil stub during linear friction welding are described. Critical clamping support structures are manufactured by a direct digital manufacturing process such as direct metal laser sintering to minimize time and expense of the process.

Abstract: An example method of attaching an airfoil for an integrally bladed rotor includes placing a support collar in an installed position around at least a leading edge and trailing edge of an airfoil stub to be repaired in an integrally bladed rotor. The support collar and the airfoil stub together have a midline that is positioned between opposing, laterally outer surfaces of the airfoil stub when the support collar is in the installed position. The method performs linear friction welding to add a replacement airfoil to the airfoil stub.

Abstract: A method of repairing an integrally bladed rotor includes the steps of placing a support collar around at least a leading and trailing edge portions of the blade stub, and performing linear friction welding to add a replacement airfoil to the blade stub. The linear friction welding is generally along a direction between the leading and trailing edges. In addition, the support collar leading and trailing edge portions are connected together.

Abstract: A method is provided for repairing a damaged rotor blade on an integrally bladed rotor by removing a damaged portion of a damaged blade leaving a blade stub extending outwardly from the disk and performing a linear friction welding operation to attach a replacement blade segment to the blade stub. The rotor may be disposed operation using a linear friction welding apparatus. The method includes disposing a support collar about the blade stub and securing the support collar to the linear friction welding apparatus prior to a commencement of the bonding operation. A lower surface of the support collar is contoured to mate with a portion of an outer circumference surface of the rotor disk.

Abstract: A method of repairing a rotor blade, for example on an integrally bladed rotor, includes preparing a surface on a damaged area of the blade. The blade has first and second airfoil surfaces adjoining the prepared surface that are spaced apart a distance. An edge of a patch abuts the prepared surface to provide a weld interface defining a welding plane. First and second cover sheets respectively overlap the first and second airfoil surfaces. The first and second cover sheets adjoin the edge and the first and second airfoil surfaces. The blade, patch and first and second cover sheets are welded along the welding plane providing a welded joint at the weld interface. The first and second cover sheets are substantially unsecured to the first and second airfoil surfaces subsequent to the welding operation.

Abstract: A method for testing ball bearings includes applying a Hertzian contact stress on a ball bearing to provide a fracture of the ball bearing that releases acoustic energy, establishing a signal representing the acoustic energy, and identifying occurrence of the fracture based upon the signal.

Abstract: A method for testing ball bearings includes applying a Hertzian contact stress on a ball bearing to provide a fracture of the ball bearing that releases acoustic energy, establishing a signal representing the acoustic energy, and identifying occurrence of the fracture based upon the signal.

Abstract: A carbo-nitriding process for forming a martensitic stainless steel, which is case hardened and superior corrosion resistance over carburized process, is provided. A process for forming a martensitic stainless steel which is case hardened is provided. The process comprises the steps of providing a material consisting essentially of from 8.0 to 18 wt % chromium, cobalt up to 16 wt %, vanadium up to 5.0 wt %, molybdenum up to 8.0 wt %, nickel up to 8.0 wt %, manganese up to 4.0 wt %, silicon up to 2.0 wt %, tungsten up to 6.0 wt %, titanium up to 2.0 wt %, niobium up to 4.0 wt % and the balance iron, and carbo-nitriding to prescribed levels of C+N, to form a hard, corrosion resistance case in a fracture tough stainless steel.

Abstract: A carbo-nitriding process for forming a martensitic stainless steel, which is case hardened and superior corrosion resistance over carburized process, is provided. A process for forming a martensitic stainless steel which is case hardened is provided. The process comprises the steps of providing a material consisting essentially of from 8.0 to 18 wt % chromium, cobalt up to 16 wt %, vanadium up to 5.0 wt %, molybdenum up to 8.0 wt %, nickel up to 8.0 wt %, manganese up to 4.0 wt %, silicon up to 2.0 wt %, tungsten up to 6.0 wt %, titanium up to 2.0 wt %, niobium up to 4.0 wt % and the balance iron, and carbo-nitriding to prescribed levels of C+N, to form a hard, corrosion resistance case in a fracture tough stainless steel.

Abstract: High modulus turbine shafts are described as are the process parameters for producing these shafts. The shafts have a high modulus as a result of having high modulus <111> crystal texture in the axial direction. The shafts are produced from a nickel base material consisting largely of the compound Ni.sub.3 Si. Hot axisymmetric deformation followed by cold axisymmetric deformation produces an intense singular <111> texture and results in shaft material whose Young's modulus is at least 25% greater than that of the steel materials used in the prior art.

Abstract: A processing sequence is described for producing specific controlled elongated oriented crystal structures in nickel base superalloys. The method is performed in the solid state. Superalloy material is provided in a dense workable form. The material is cold straight rolled and cold cross rolled with intermediate anneals. This sequence produces a particular texture or preferred orientation in the rolled article. This textured article is then directionally recrystallized to produce the desired final microstructure comprised of aligned elongated grains of a particular controllable orientation.

Abstract: High modulus turbine shafts are described as are the process parameters for producing these shafts. The shafts have a high modulus as a result of having high <111> texture in the axial direction. The shafts are produced from a nickel base material having a strengthening phase and a moderate to high stacking fault energy. A combination of hot axisymmetric deformation followed by cold axisymmetric deformation produces an intense singular <111> texture and results in shaft material whose modulus is on the order of 25% greater than that of the steel materials used in the prior art.