Structural and mechanical aspects of hypoeutectic Zn–Mg binary alloys for biodegradable vascular stent applications  

作　　者：W.Pachla S.Przybysz A.Jarzębska M.Bieda K.Sztwiertnia M.Kulczyk J.Skiba 

机构地区：[1]Institute of High Pressure Physics,Polish Academy of Sciences UNIPRESS,Warszawa,Poland [2]Institute of Metallurgy and Materials Science,Polish Academy of Sciences,Krakow,Poland

出　　处：《Bioactive Materials》2021年第1期26-44,共19页生物活性材料（英文）

基　　金：the National Science Centre(Poland),grant UMO-2016/23/B/ST8/00724.

摘　　要：The study is concerned with the mechanical properties of Zn and three Zn–Mg double alloys with Mg concentrations:0.5%,1.0%and 1.5%in the form of rods with a diameter of 5 mm as potential materials for use in biodegradable medical implants,such as vascular stents.The materials were cast,next conventionally hot extruded at 250°C and finally,hydrostatically extruded(HE)at ambient temperature.Occasionally HE process was carried at liquid nitrogen temperature or in combination with the ECAP process.After HE,the microstructure of the alloys was made up of fine-grainedαZn of mean grain size~1μm in a 2-phase coat of 50–200 nm nanograins of the fineαZn+Mg2Zn11 eutectic.The 3 to 4-fold reduction of grain size as a result of HE allowed an increase in yield strength from 100%to over 200%,elongation to fracture from 100%to thirty fold and hardness over 50%compared to the best literature results for similar alloys.Exceptions accounted for elongation to fracture in case of Zn-0.5 Mg alloy and hardness in case of Zn-1.5 Mg alloy,both of which fell by 20%.For the Zn-0.5 Mg and Zn–1Mg alloys,after immersion tests,no corrosive degradation of plasticity was observed.Achieving these properties was the result of generating large plastic deformations at ambient temperature due to the application of high pressure forming with the cumulative HE method.The results showed that Zn–Mg binary alloys after HE have mechanical and corrosive characteristics,qualifying them for applications in biodegradable implants,including vascular stents.

关 键 词：Biodegradable Zn alloys Hydrostatic extrusion Microstructure Mechanical properties Vascular stent 

分 类 号：TG146[一般工业技术—材料科学与工程]