Corrosion state of iron and bronze artifacts excavated from Nishizuka Mound, Fukui Prefecture

Mitsui, Seiichiro  ; Yoshikawa, Hideki; Tokuda, Masashi*; Seiki, Yuji*

Ancient iron and bronze artifacts (ca 1,500 year old) excavated from Nishizuka Mound, Fukui Prefecture, were studied as archaeological analogues for metal overpack corrosion. As for corrosion state, we analyzed corrosion volume with a X-ray CT and corrosion products with a portable XRD/XRF. As results, we found that corrosion volume of bronze artifacts were smaller than those of iron artifacts and that cassiterite (SnO) was present as one of corrosion products on the surface of the bronze artifacts. This suggested that the cassiterite inhibited corrosion reaction of the bronze artifact.