湖北出土战国青铜剑表面富锡层的材料学特征

Analysis of Material Characteristics of Tin-Rich Surface Layer on Warring States Bronze Swords Unearthed in Hubei by Nano-Indentation Technique

利用纳米压痕技术,对3把出土于湖北的战国青铜剑残片表面富锡层的力学性能进行测试,并结合金相显微镜、扫描电镜、能谱仪和X射线衍射仪等仪器对其显微组织特征、合金成分进行了系统的表征。研究分析认为:(1)3把青铜剑残片属高锡青铜,表面存在一层由δ相和非晶化合物构成的富锡层;(2)其双层结构中的惰性腐蚀层的特征表明富锡层是在长期埋藏环境中由于发生选择性腐蚀而形成的,排除了古代工匠人为处理的可能性。纳米压痕技术为古代金属样品微米级微区的力学性能的准确测试提供了有力的工具。

The mechanical properties of the tin-rich surface layers on three pieces of Warring States bronze swords unearthed in Hubei province were measured using nano-indentation technique.The microstructure,elemental composition and crystal structure of the Sn-rich surface layers were analyzed with an optical microscope,a scanning electron microscope,an energy dispersive spectrometer and an X-ray diffractometer.Results reveal that all the three swords consist of bronze with a high content of Sn,and the tin-rich layers consist of δ-phase and amorphous compounds.In the meantime,according to the features of the inert corroded layers of the dual-layer structure of the swords,their Sn-rich surface layers may be formed owing to selective corrosion during long-term burial rather than artificial treatment of ancient craftsmen.The present research proofs that nano-indentation technique can be well used to determine the micro-zone mechanical properties of ancient metal reliques.