한국주조공학회

To overcome the undesirable deformation, peeling offand geometrical restrictions which were mainly caused by differences in thermal expansion coefiicients during the cladding of aluminum strip and stainless strip, new processing method based on vac- uum die casting is designed and implemented in fabricating Fe-17wt%Cr steel (stainless steel). To increase cast-bonding ability, the surface of Fe- I 7wt%Cr steel is electrochemical etched to have optimum pit size (above 0.2 mm) and pit density (above 30%). The implementation of vacuum die casting by using surface treated stainless steel (Fe-l7wt%Cr Steel) produces good trial prod-ucts having acceptable cast-bonding ability. The enabling conditions for cast-bonding are pouring temperature 69oC, filling speed 30 m/sec and casting pressure 800 kg/cmz. The microscopic observation of cast-bonded Al/Fe-l7wt%Cr steel does not show any evidence of intermetallic compounds. The bonding strength oftrial products is 150-400 kg/cni and this is stronger than conventionally cladded metal having 30-70 kg/cmz.