Metallography & Reconstruction of Ancient Hammered Bronze
锤揲古铜器的金相分析与技法复原
标签：金相分析, 退火孪晶, 实验考古, 锤揲
金相是判定古铜器"铸或锻"的直接证据：铸态呈树枝晶与（α+δ）共晶，锤揲退火态呈等轴 α 晶粒加退火孪晶；晶粒拉长方向记录最后变形方向，均匀孪晶晶粒说明成器后经过退火。硬度分布可量化工艺：铸态锡青铜约 90–120 HV，冷锤后升至 150–180 HV。伦敦大学学院考古研究院等机构的复原实验按"热锻开坯—冷锤整形—间歇 600–650℃ 退火"流程复制锤揲器物，测得的锤痕间距与晶粒尺寸为博物馆修复和真伪鉴定提供参照系。
Metallography is the direct test of cast versus hammered: as-cast shows dendrites plus (α+δ) eutectoid; hammered-and-annealed shows equiaxed alpha grains with annealing twins — elongated grains record the final deformation direction, uniform twinned grains a post-shaping anneal. Hardness mapping quantifies the work: cast tin bronze sits at 90–120 HV, rising to 150–180 HV after cold hammering. Reconstruction programs such as those at UCL's Institute of Archaeology replicate vessels by hot forging the blank, cold-shaping, and annealing at 600–650°C between rounds, giving conservation and authentication a reference frame of hammer-mark spacing and grain size.