Tunable mechanical and degradation properties of biodegradable Mg-Y-Zn alloys via Zn content regulation
Tunable mechanical and degradation properties of biodegradable Mg-Y-Zn alloys via Zn content regulation
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通过锌含量调节可生物降解的 Mg-Y-Zn 合金的机械和降解性能
DOI：
10.1016/j.jmrt.2022.08.080
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发表时间：
2022-09-05
影响因子：
6.4
通讯作者：
Hu, Taobo
中科院分区：
文献类型：
--
作者：
Lu, Xianzheng;Zou, Xianjun;Hu, Taobo
通过力学性能和体外降解试验，研究了Zn含量对可生物降解Mg-Y-Zn（WZ）合金力学性能和降解行为的影响。显微组织分析表明，随着Zn含量的增加，第二相的形貌和成分发生了显著变化。长周期堆垛有序相的连续析出使WZ合金的强度提高。随着Zn含量的增加，WZ合金的耐蚀性先增加后降低。在Mg-9.1Y-1.8Zn（WZ 92）合金中，连续的棒状LPSO相形成了有效的降解屏障，阻止了腐蚀渗透，从而导致了均匀缓慢的降解过程。不连续的和分散的（即，Mg-9.2Y-3.1Zn（WZ 93）合金中的LPSO相不能起到降解屏障的作用，晶内细小的层状结构会加剧腐蚀，促进腐蚀向α-Mg基体的渗透。另外，LPSO相含量高的WZ 93合金形成的微电偶较多，加剧了微电偶腐蚀。交流阻抗谱结果表明，WZ 92合金表面形成了较厚、较稳定的膜，具有较好的耐蚀性。本研究表明，通过调节Zn含量，可以高效、经济地制备出力学性能和降解性能可调的Mg-Y-Zn合金，有望成为可降解医用植入物领域的一种候选材料。(c)2022作者（S）由爱思唯尔有限公司出版。这是一篇开放获取的文章，获得了CC BY-NC-ND许可证（http：//creativecommons.org/licenses/by-nc-nd/4.0/）。
This study aims to explore the effect of Zn content on mechanical properties and degra-dation behaviour of biodegradable Mg-Y-Zn (WZ) alloys via mechanical and in-vitro testing. Microstructure characterization showed that the morphology and composition of the secondary phases changed significantly with the increase of Zn content. The contin-uous precipitation of long-period stacking ordered (LPSO) phase led to an increase in the strength of the WZ alloys. However, the corrosion resistance of the WZ alloys increased initially and then decreased as Zn content increased. In the Mg-9.1Y-1.8Zn (WZ92) alloy, the continuous rod-like LPSO phases formed an effective degradation barrier to prevent the corrosion penetration, thus leading to a uniform and slow degradation process. Discon-tinuous and dispersed (i.e., lamellar-like) LPSO phase existed in the Mg-9.2Y-3.1Zn (WZ93) alloy cannot act as the degradation barrier, and the intragranular fine lamellar structure would aggravate corrosion and promote corrosion penetration into the a-Mg matrix. In addition, the WZ93 alloy with high content of LPSO phase formed more micro-galvanic couples, which exacerbated the micro-galvanic corrosion. EIS results revealed that the WZ92 alloy exhibited better corrosion resistance due to the formation of a more stable and thicker surface film. This study demonstrates that the Mg-Y-Zn alloy with tunable me-chanical and degradation properties can be fabricated efficiently and economically by regulating the Zn content, and is expected to be a promising candidate in the field of degradable medical implant.(c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).