巴蜀青铜兵器热镀锡工艺

采用SEM、XRD和矿相分析方法对几件战国带虎斑纹的巴蜀兵器样品进行分析.样品基体为铸态组织且铸后经过加热;斑纹与基体有明显的界面,斑纹是高锡的铜锡合金,厚度在20~40μm;斑纹主要是由SnO₂与Cu₄₁Sn₁₁组成.根据分析结果并分别用镀高锡合金法、热镀锡法进行模拟实验,初步认为虎斑纹系人工表面处理得到,处理工艺应为热镀锡.组织观察到从基体向镀层方向生长的柱状晶,应是铜向液态锡中溶解扩散所致;镀层中δ相的存在,可能热镀锡后又经过退火的过程.

Hot-tinning craft of Ba-Shu bronze weapons

Three samples with mottle (Hu-ban-wen) were analyzed by using SEM, XRD and microscope. The matrix of these samples was cast and then heated. Distinct interface between the matrix and mottle existed. The mottle layer was high tin bronze and the thickness was about 20-40μm. SnO₂ and Cu₄₁Sn₁₁ were main composition of the mottle layer. Some experiments were carried out by using the methods of coating with Cu-Sn alloy solution and hot-tinning. Clear boundary and columnar crystal growing could be seen clearly by all these methods and varied thickness of the coating was caused by different heating conditions. The result shows that the mottle is artificial, the columnar crystal growing from substrate to coating should be caused by dissolving and diffusion of copper into liquid tin and δ phase maybe caused by hot-tinning and annealing.