Synthesis, mechanical properties, and in vitro corrosion behavior of biodegradable Zn-Li-Cu alloys

[摘要] Zinc alloys are proposed as suitable biodegradable materials due to an intermediate corrosion rate, non-toxicity, and good mechanical properties. The novel ternary Zn-Li-Cu alloy system is explored in this study as a potential biodegradable material for stent and other temporary medical device applications, utilizing pure Zn, Zn-Li, and Zn-Cu as control materials. After casting and hot-rolling, the chemistry, microstructure, mechanical properties, and immersion corrosion behavior of Zn-0.3Li-xCu (x = 2, 3.5, and 5 wt%) are investigated. The simulated Zn-Li-Cu ternary phase diagram compares well with experimental chemistry and phase fractions. Zn-Li-Cu alloys demonstrated excellent ultimate tensile strength (333-428 MPa) and hardness (125-134HV), with acceptable elongation (18-26%) compared to general stent design criteria and similar materials. In vitro corrosion rates of approximately 0.01 mm yr(-1) were observed after 21 days of immersion in Hank's Balanced Salt Solution (HBSS), where depletion of metal ions is slowed by the formation of a dense corrosion product layer that partially breaks down after 100 days. The current study highlights that the novel Zn-Li-Cu alloys are promising candidates for medical device applications by exceeding stent design criteria. (c) 2020 Elsevier B.V. All rights reserved.

[发布日期] 2020-12-05

[关键词] Zn-Li-Cu;Hot-rolling;Corrosion;Mechanical properties;Microstructure;Phase diagram