Method for diffusion welding under isostatic pressure

DETAILED DESCRIPTION According to the invention structural components are joined to each other by diffusion welding involving the combination of the following steps.
A metallurgical layer is applied to part or all of at least one of the joint forming surfaces of the parts to be connected with each other.
The metallurgical layer has a melting point below the temperature required for the hot isostatic pressing.
This temperature must be below the temperature at which the metallurgical layer would melt onto the welding joint forming surface or surfaces.
When the two components are engaged with each other a joining gap is formed in which the metallurgical layer is located for sealing the joining gap.
The metallurgical layer may be provided in several different ways prior to the assembly of two parts or after the assembly of these parts.
The welding is performed by subjecting the assembled parts with said layer therebetween to a hot isostatic pressing process for accomplishing a material diffusion of said metallurgical layer through the joint forming surfaces.
The invention is basically a two-phase operation.
In the first phase the metallurgical layer is applied to at least part of at least one of the surfaces which will form the welding joint, or to both surfaces.
In this first phase and when the parts are assembled the joining gap is closed and sealed by the metallurgical layer.
The second phase involves the diffusion welding in a hot isostatic press.