US 4,529,452 A · Process for fabricating multi-alloy components

Abstract

A component, such as a turbine disk, made from a metal or metal alloy which has been processed to display superplastic properties at elevated temperatures, is diffusion bonded to a component or components, such as turbine blades, made from another metal or metal alloy, by disposing the components in a press with the surfaces to be bonded in mating contact. Moisture and oxygen are removed from between the surfaces. Heat and pressure are then applied, such as by forging at an elevated temperature or by hot isostatic pressing, to cause superplastic deformation of at least one of the components at the bonding surfaces. The heat and pressure are held sufficiently long to diffusion bond the surfaces. The new integral assembly is then heat treated to obtain desired properties. Consistently good diffusion bonds are achieved by this method.

Claims20

Dependent claims

A method for joining a first element made from a first superalloy material to a second element made from a metal which is a different material from said first material, including the steps of:

processing said first material such that it exhibits the property of becoming superplastic during the subsequent step of heating and applying pressure, and fabricating said first element from said processed first material, said first element having a bonding surface, said second element also having a bonding surface adapted to mate with the bonding surface of the first element;
positioning said first and second elements within a press such that their bonding surfaces are in mating contact;
and
heating said first and second elements within said press and simultaneously applying pressure thereto to obtain (1) superplastic deformation of said first element at its bonding surface where it mates with the bonding surface of said second element to create line-on-line contact over said surface and (2) a solid state diffusion bond at said mating surfaces to form an integral assembly.

1 more element

In a method for fabricating an integrally bladed rotor having blades made from a first material of a metal having a predetermined desired crystallographic grain orientation, said blades being integral with a disk made from a superalloy having different properties from said first material, wherein said blades are bonded directly to the rim of said disk, including the steps of:

fabricating a disk preform by processing said superalloy disk material such that said preform has the property that it becomes superplastic at elevated temperatures, including forming a radially outwardly facing first bonding surface on said preform;
fabricating individual blade elements of said first material, each having said desired grain orientation and each having a radially inwardly facing second bonding surface adapted to mate with said first bonding surface;
positioning said blade elements accurately relative to one another about the periphery of said disk preform with their second bonding surfaces in mating contact with said preform first bonding surface to form a first group of components, and disposing said group of components within a press;
heating said group of components within said press and simultaneously applying pressure thereto to obtain:
(1) superplastic deformation of said disk preform at the interfaces of said first and second bonding surfaces and
(2) a solid state diffusion bond at said interfaces to form an integral assembly;
and
heat treating said integral assembly to obtain strength and hardness of the materials in said assembly.

5 more elements

Dependencies are inferred from the claim text.

Process for fabricating multi-alloy components

Life of this patent

Process for fabricating multi-alloy components

Life of this patent

Abstract

Claims20