Discoloration Process of Minted Copper-Nickel Alloys in Chloride Ion-Containing Environments: Experimental and DFT Research
學年 113
學期 2
出版（發表）日期 2025-03-22
作品名稱 Discoloration Process of Minted Copper-Nickel Alloys in Chloride Ion-Containing Environments: Experimental and DFT Research
作品名稱（其他語言）
著者 Chenzhi Xing; Ming-Hsien Lee; Gongwang Cao; Yuwei Liu; Quanzhong Guo; Zhenyao Wang; Chuan Wang
單位
出版者
著錄名稱、卷期、頁數 Acta Metallurgica Sinica (English Letters) 38(6), p.925-945
摘要 A corrosion discoloration model for copper–nickel alloys in Cl− environments was established using CIE-Lab, UV–VIS absorption spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The corrosion discoloration process and the corresponding main corrosion products can be summarized as follows: silver-white (Cu + Ni) → green (NiO) → reddish-brown (NiO + Cu2O) → black (NiO + Cu2O + CuO). Density functional theory was employed to explain the corrosion process of copper–nickel alloys and the detrimental effect of Cl−. The results indicate that adsorbates preferentially bind to nickel, leading to the preferential formation of NiO, which imparts a green appearance to the surface. Furthermore, the difficulty in forming nickel cation vacancies and the higher diffusion barrier for nickel inhibit the migration of species within the oxide layer. Notably, nickel also suppresses carrier migration within the oxide layer, reducing the charge transfer rate. In contrast, the promotion of corrosion by Cl− is primarily attributed to the reduction in surface work function and the formation energy of cation vacancies.
關鍵字 Copper–nickel alloy; Coinage material; Discolor; Cl−; Density functional theory (DFT)
語言 en
ISSN 2194-1289; 1006-7191
期刊性質 國外
收錄於 SCI
產學合作
通訊作者
審稿制度 否
國別 CHN
公開徵稿
出版型式 ,電子版,紙本
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/129536 )