LIQUID-PHASE BONDING OF ALUMINUM AND ALUMINUM NICALON COMPOSITE USINGCOPPER INTERLAYERS

The liquid phase bonding, in air, of unreinforced and fibre reinforced aluminium using copper interlayers has been investigated. Bond streng ths have been measured and microstructures characterised using electro n microscopy and electron probe microanalysis. The diffusion behaviour and interphase reactions, which depend on the bonding conditions, are discussed, and a mechanism for the formation of a liquid phase bond i s proposed. For unreinforced aluminium a bonded area of approximately 100% was achieved at 550-degrees-C by applying a pressure of 10 MPa fo r 30 min to the joint while using a 10 mum thick copper interlayer. Wi th the composite it was necessary to use a higher bonding pressure (20 MPa) in order to limit oxidation of the copper and maximise the bonde d area (to approximately 80%). (C) 1993 The Institute of Materials.