BONDING SHEETS

摘要

A method of bonding together two bodies of the same or different metals at least one of which forms an oxidized coating thereon so readily as to be inherently incapable of being fusion bonded to the other body comprises creating two composite bodies by coating the bodies with metallic layers which are capable of being bonded together by the application of pressure at an elevated temperature lower than the melting point of either body. Each layer is applied to its associate body by a process in which: 1) the oxidized coating on each body is physically broken up and at the same time 2) a new metal surface of increased superficial area is formed on the body while it is in intimate contact with its associated layer to prevent the ingress of air therebetween and the oxidation of the new metal surface so that 3) the body and its associated layer become bonded together in metal to metal contact and the layer diffuses into the body over substantially the whole of the increased area. The composite bodies are thereby bonded together with at least predetermined parts of their layers in direct metal to metal contact with one another by a process which does not increase the surface area and is selected from diffusion bonding and transient liquid phase bonding whereby the layers diffuse into one another and further diffuse into the bodies with any excess metal from the layers being expelled from between the predetermined parts until a discrete identity of the layers has been lost and the bodies are effectively bonded directly together.