Development and evaluation of a magnesium-zinc-strontium alloy for biomedical applications - Alloy processing, microstructure, mechanical properties, and biodegradation
Development and evaluation of a magnesium-zinc-strontium alloy for biomedical applications - Alloy processing, microstructure, mechanical properties, and biodegradation
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DOI：
10.1016/j.msec.2013.04.054
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发表时间：
2013-10-01
影响因子：
7.9
通讯作者：
Liu, Huinan
中科院分区：
文献类型：
--
作者：
Guan, Ren-guo;Cipriano, Aaron F.;Liu, Huinan
开发并研究了一种新型可生物降解的镁锌锶合金，用于医用植入物。这第一项研究调查了合金加工(铸造、轧制和热处理)、显微组织、力学性能和在模拟体液(SBF)中的降解性能。与铸态合金相比，ZSr41合金在175℃时效8h后的力学性能有所提高。具体来说，时效后的ZSr41合金的抗拉强度为270 Mpa，维氏硬度为71.5HV，断裂伸长率为12.8%。ZSr41合金的力学性能优于纯镁合金，满足承载医用植入物的要求。此外，ZSr41合金在SBF中的浸泡呈现出一种循环发展的退化模式，点蚀和局部腐蚀交替进行。时效ZSr41合金在SBF中的稳态平均降解速率为0.96g/(m(2)·hr)，而SBF浸泡液的pH值升高。ZSr41合金在SBF溶液中的腐蚀电流密度为0.41 mA/mm(2)，远低于相同条件下纯镁的1.67 mA/mm(2)。综上所述，与纯镁相比，由于添加了锌和锶合金元素以及特定的工艺条件，新型ZSr41合金的力学性能有所提高，但退化速度有所降低。新型ZSr41合金优异的力学性能和耐腐蚀性使其成为下一代植入物应用的极有前途的合金。(C)2013爱思唯尔B.V.保留所有权利。
A new biodegradable magnesium-zinc-strontium (Mg-Zn-Sr) alloy was developed and studied for medical implant applications. This first study investigated the alloy processing (casting, rolling, and heat treatment), microstructures, mechanical properties, and degradation properties in simulated body fluid (SBF). Aging treatment of the ZSr41 alloy at 175 degrees C for 8 h improved the mechanical properties when compared to those of the as-cast alloy. Specifically, the aged ZSr41 alloy had an ultimate tensile strength of 270 MPa, Vickers hardness of 71.5 HV, and elongation at failure of 12.8%. The mechanical properties of the ZSr41 alloy were superior as compared with those of pure magnesium and met the requirements for load-bearing medical implants. Furthermore, the immersion of the ZSr41 alloy in SBF showed a degradation mode that progressed cyclically, alternating between pitting and localized corrosion. The steady-state average degradation rate of the aged ZSr41 alloy in SBF was 0.96 g/(m(2).hr), while the pH of SBF immersion solution increased. The corrosion current density of the ZSr41 alloy in SBF solution was 0.41 mA/mm(2), which was much lower than 1.67 mA/mm(2) for pure Mg under the same conditions. In summary, compared to pure Mg, the mechanical properties of the new ZSr41 alloy improved while the degradation rate decreased due to the addition of Zn and Sr alloying elements and specific processing conditions. The superior mechanical properties and corrosion resistance of the new ZSr41 alloy make it a promising alloy for next-generation implant applications. (C) 2013 Elsevier B.V. All rights reserved.