Reverse cladding of 304 stainless steel to LM25 aluminium alloy through die-casting

Abstract

Stainless steel (SS) coatings/claddings over aluminium alloy (AA) substrates have been practiced through friction surfacing, thermal and cold gas spraying, laser coating, and diffusion bonding. In this work, 304-grade SS is reverse-cladded to an LM25 AA through die-casting using a surface-prepared sheet insert. The clad-substrate interface was characterized micrographically and compositionally through optical and electronic microscopic techniques. Micrographs revealed that reverse cladding was achieved successfully by forming an intermetallic zone (IMZ). The IMZ contains four intermetallic layers (IMLs) of varying thickness with 6.42 ± 2.04 µm near the central region. Electron probe microanalysis showed Fe3(Al, Si), Fe3(Si, Al), Fe(Al, Si), and Fe3Al15Si2 are the associated phases with four IMLs from the SS to AA side, respectively.