Microstructure at interface of steel/aluminum bonding sheet and formation of intermetallic compound

This paper deals with the relation between the microstructure and the formation of intermetallic compound(IMC) at the interfaces of the bonding sheets. The bonding sheets, steel/aluminum alloy(CS/A5) and stainless steel/pure aluminum (SS/Al), were produced by hot rolling. From the results of TEM observation, it was found that aluminum or chromium oxide films were existed and the IMC were formed locally at the interfaces of the bonding sheets. Two or three types of the IMC composed of columnar structure were formed at the interfaces of the bonding sheets after heating. The oxide films remained at the IMC/aluminum interfaces of the CS/A5 bonding sheets. The specific crystallographic orientation relationship was recognized at the SS/IMC interfaces of the SS/Al bonding sheets. It was considered that the formation of the IMC were greatly effected by the oxide films existed at the interfaces of the bonding sheets.