Mg-Zn-Ca三元镁合金生物材料的腐蚀行为研究..doc

文章编号：1004-0609(2010)05-0891-07 Mg-Zn-Ca三元镁合金材料欧阳春雷霆，中南大学 粉末冶金国家重点实验室，长沙 4100摘要：以ZnCa为合金，制备生物可降解材料，Hank模拟体液中腐蚀及电化学腐蚀不同腐蚀时间的表面形貌组织相成分结果表明：镁合金的腐蚀是从点蚀开始合金中Mg2Ca合金中Mg2Ca关键词： 文献标志码：A Corrosion behaviours of ternary Mg-Zn-Ca alloy biomaterials OUYANG Chun1, LEI Ting1, WANG Li1, LI Nian-feng1, 2, ZHOU Le-shan3 (1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China; 2. Xiangya Hospital, Central South University, Changsha 410008, China; 3. Xiangya School of Medicine, Central South University, Changsha 410013, China) Abstract: With elements of Zn and Ca as alloy components, three kinds of degradable ternary Mg-Zn-Ca alloys with Ca contents of 1%, 2% and 3%(mass fraction), respectively, were fabricated by melting and casting. The mass loss measurement and electrochemical corrosion technique were employed to study their corrosion behaviours in Hank’s simulated body fluid. The results based on the SEM morphology observation and analyses of structures and phases show that the corrosion of Mg alloy begins from pitting corrosion at Mg matrix. The ternary alloy with 1% Ca shows an enhanced corrosion resistance, and the existence and distribution of Mg2Ca phase in alloy significantly affect its corrosion-resisting performance. The content of Mg2Ca phase in alloy increases with the increase of Ca content, leading to a poor corrosion resistance for alloy. Key words: Mg-Zn-Ca alloy; Hank solution; electrochemical corrosion; Mg2Ca phase; biodegradation 近年来，镁及镁合金作为金属基生物材料受到越来越多的关注。镁是一种轻质金属，具有与人体骨膜相近的密度[1?2]和弹性模量[3]，且无毒[4]、生物相容性好等优点。与目前临床上普遍采用的钛合金、不锈钢金属植入材料新陈代谢完全排出体外。镁的标准电极电位为?2.34 V， 基金项目：国家自然科学基金资助项目；中南大学粉末冶金国家重点实验室开放基金资助项目 收稿日期：2009-03-09；2009-08-25 通信作者：雷 霆，教授，博士；电话E-mail: tlei@mail.csu.edu.cn  泼，单纯的金属镁在介质中极易发生腐蚀，因此，通常采用合金化来增强镁的耐腐蚀性能。目前，生物医用镁合金的研究主要集中在Mg-RE合金系列WITTE等[7]比较了AZ31、AZ91、WE43和LAE422这4种镁合金种植体在动物体内的腐蚀降解特点和骨组织对镁植入体的反应，发现镁合金具有比可降解聚合物更好的骨组织相容性和骨组织诱导性能。这些