임진왜란기 화약 무기의 제작기술 검토- 성분분석 및 미세조직 분석 사례를 중심으로 -

Abstract

Although there was a great development on gunpowder weapons, which represent the advanced technologies of the time, from late Goryeo dynasty to after the Japanese invasions of Korea, its process of development has not been studied in depth due to the lack of literature. The purpose of the present study is to examine manufacturing techniques of various artefacts using analysis of the gunpowder weapons either used or made during the Japanese invasion of Korea. Bronze cannons are a ternary casting alloy of Cu-Sn-Pb with different alloy ratios, high lead ratio over 8% in Bulanggijapo(cannon) but low in Suengjachongtong(gun) depending on the gun types. However, there are similarities that they are cast bronze alloys produced by slow cooling and made using sulfide bearing copper ore. The high amount of impure inclusions in the weapons indicate underdeveloped refining technique at the time. The iron guns were forged and the large amount of non metallic inclusions suggest iron bloom or sponge iron obtained by low temperature reduction was used. In the case of large iron cannon, casting is appropriate because its thick gunbarrel is strong enough to stand gunpowder explosion. However, the small gunpowder weapons were so vulnerable to explosions that forging techniques was necessary. The Metal projectiles were made of various metals such as iron, bronze, and lead. It is believed that about 10% of lead in the bronze cannons was to increase the fluidity of molten alloy or to decrease the content of copper and tin, which had a high level of dependance on imports. Thus, very high purity of the lead balls was to maximize the machinability as well as weight. Two techniques, casting and forging for the large and small cannon balls respectively, indicate that the cannon balls were made by differently depending on the size and purpose.