BONDING OF ALUMINUM-MATRIX COMPOSITES FOR APPLICATION IN THE TRANSPORT INDUSTRY

A discontinuously reinforced MMC containing 12 vol % SIC particles in an Al-Cu-Mg alloy (AA 2124) matrix has been diffusion bonded. Thick in terlayers of different superplastic aluminium alloys (Al-Li 8090 and A l-Cu SUPRAL) were used to reduce the bonding pressure and ensure compl ete surface contact. Microstructural studies shown higher continuity i n joints bonded with 8090 interlayer than with other alloys. Precipita tion of rich-copper intermetallic was detected, after bonding, in the interlayer because diffusion of Cu from 2124 matrix. Results suggest t hat Li contained in the interlayer favours the partial disruption of t he aluminium oxide film, making easier the solid state bonding.