Aluminum–aluminum compound castings by electroless deposited zinc layers

Sandblasted aluminum sheets (Al 99.5) were coated with a basic zincate solution and integrated into high pressure die casting components (AlSi9Cu3(Fe)) with wall thickness ranging from 3 mm to 6 mm. Investigations of the Al–Al-interface showed that sound castings could be realized. Microprobe analysis was used to elucidate the dissolution and diffusion of the Zn coating as a function of the processing parameters. Due to the very small total amount of zinc we did not find a zone of brittle intermetallic phases at the interface. Shear testing of the compounds confirmed the presence of a firmly bonded compound without embrittlement by intermetallic phases.