A new perspective on the study of thermal treatment processes of Asian bronze : a view from modern Korean Yugi ware

High-tin bronze tends to have relatively low-strength. Nevertheless, the alloys were frequently used as raw materials of mirrors, weapons and musical instruments in antiquity. Investigations of traditional high-tin bronze manufacturers in modern Korea and India revealed that forming of high-tin bronze products with a content of around 22% tin was performed through casting or hot forging in the temperature range between 550 and 780℃. In particular, hot forging has enabled us to fabricate bronze bowls with thin (approximately 0.3mm) wall. The investigations also revealed that hot forged bronze bowls were subsequently water quenched from the temperature range between 650 and 740℃ in order to increase the strength of the products. Due to the results, metallographic examination of bronze artifacts allowed us to shed new light on fabrication techniques of ancient high-tin bronze products.