Exploring the corrosion behavior of Mn-implanted biomedical Mg

• Published in: Journal of alloys and compounds 2021-08, Vol.873, p.159739, Article 159739
• Main Authors: Dong, Qiangsheng, Jia, Yongqiang, Ba, Zhixin, Tao, Xuewei, Wang, Zhangzhong, Xue, Feng, Bai, Jing
• Format: Article
• Language: English
• Subjects: Corrosion; Corrosion effects; Corrosion rate; Corrosion resistance; Galvanic corrosion; Ion implantation; Magnesium; Manganese; Metal vapors; Pitting (corrosion); Scale (corrosion); Submerging
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.159739

•The Mn-implanted layer on biomedical Mg was composed of Mg, Mn, and their oxides.•The galvanic coupling between metallic Mn and Mg accelerated the corrosion rate.•The Mn-implanted Mg changed from corrosion-prone to corrosion-resistance during immersion.•Ca, P-containing products were uniformly formed on Mn-implanted Mg.•The Metallic Mn in the implanted layer was oxidized during immersion. [Display omitted] Many surface modification technologies have been developed on biomedical magnesium (Mg) and its alloys to expand potential clinical applications. In this study, the bio-safe manganese (Mn) element was implanted into the biomedical Mg surface by a metal vapor vacuum arc (MEVVA) technique. In the Mn-implanted layer, Mn existed in the form of both metallic and oxidized states. Besides, Mn ion implantation changed the corrosion behavior of biomedical Mg in Hank’s solution. At the initial stage of immersion, the corrosion rate was accelerated owing to the galvanic couple between metallic Mn and Mg, and micro-scale galvanic corrosion was uniformly distributed on surfaces. With the immersion time prolonging, Mn-implanted Mg displayed enhanced anti-corrosive property, presenting as a change from corrosion prone to corrosion resistance. On the one hand, the anti-corrosive and uniform Ca, P-containing products were formed on the corroded surface based on uniformly-distributed micro-scale pitting corrosion. On the other hand, the metallic Mn tended to be oxidized to stable Mn oxide so that galvanic corrosion was retarded. This research attempts to explore the effect of Mn ion implantation on the corrosion behavior of biomedical Mg, and offers new insight into novel surface modifications of biomedical Mg devices for long-time implantation.