(1. 中南大学 材料科学与工程学院,长沙 410083;
2. 中国印钞造币总公司 沈阳造币技术研究所,沈阳 110042)
摘 要: 设计并制备一种新型的抗变色仿金稀土铜合金。采用金相组织分析、中性盐雾试验、质量损失法、电化学阻抗谱和扫描电镜等手段对比研究所设计合金与现有造币用H72-1-1合金的组织结构、抗变色性能和耐蚀性能。结果表明:所设计合金退火组织细小、均匀,在3.5%NaCl溶液中保持不变色的时间较H72-1-1合金的延长了25%。在3.5%NaCl溶液中浸泡腐蚀过程中,所设计合金形成了一层均匀致密、完整的腐蚀产物膜,减缓了腐蚀的进程,其耐腐蚀性能优于H72-1-1合金的,腐蚀速率为10.3 μm/a;所设计合金电荷转移电阻Rct、Warburg扩散阻抗ZW与H72-1-1合金的相比都有大幅度的提高,腐蚀过程阻力增加。
关键字: 仿金合金;铜合金;抗变色性能;耐蚀性能
novel colour-stable imitation gold copper alloy with rare earth
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Research Institute of Shenyang Mint, China Banknote Printing and Minting Corporation, Shenyang 110042, China)
Abstract:A novel colour-stable imitation gold copper alloy with rare earth was designed and prepared. The microstructures, anti-tarnishing and corrosion resistance properties of the designed alloy and the existing mint metal of H72-1-1 were compared by means of metallographic analysis, neutral salt spray test, mass loss measurement, electrochemical impedance spectroscopy and scanning electron microscopy. The results show that the annealed microstructure of the designed alloy is fine and homogeneous, and discoloring time of the alloy in 3.5% NaCl solution is 25% longer than that of H72-1-1 alloy. The mass loss rate of the designed alloy is slightly lower than that of the H72-1-1 alloy in 3.5% NaCl solution, which can be attributed to the uniform and compact corrosion film which retards the corrosion process, and the corrosion rate is 10.3 μm/a. The charge transfer resistance Rct and the diffusion impedance ZW of the designed alloy increase much more greatly than those of the H72-1-1 alloy, which increases the corrosion process resistance.
Key words: imitation gold alloy; copper alloy; anti-tarnishing performance;corrosion resistance performance