As degradable biomaterials,the higher degra-dation rate of Mg-Li alloys in the physiological environment is the main challenge for the implant applications.In order to try and overcome this limitation,the present work was dedicated to studying the corrosion behavior of a novel Mg-13Li-X alloy fabricated by a rapid solidification process(RSP).The special Mg-13Li-X alloy was immersed in Hank's balanced salt solution(HBSS),and the influence of immersion time on corrosion rate was analyzed.X-ray diffraction(XRD)and scanning electron microscopy(SEM),complemented with electrochemical techniques such as potentiodynamic polarization curves and electrochemical impedance spectroscopy,were applied.Microstructural characterization indicates that the mean grain sizes of RSP Mg-13Li-X alloy are 4.2,8.2 and 12.7 μm with the solidi-fication rate decreasing.By contrast,the conventional as-cast Mg-13Li-X alloy has an average grain size of about 150 μm.The results of electrochemical test indicate that the sample with 4.2 μm in grain size has the most positive cor-rosion potential(Ecorr)of-1.354 V and the minimum cor-rosion current(Icor)of 5.830×10-7 A·cm-2 after immersion for 2 h in HBSS.Therefore,the finest grain size can improve the polarization resistance of the alloy,reduce its corrosion current density and increase its corrosion resistance.However,because the weak layer of the corrosion product which consists of Mg(OH)2 does not afford strong protection,the corrosion resistance becomes worse after immersion for longer periods.

Bao-Liang Wu;Bing Chen;Cheng-Wei Wang;Jing-Ye Jiao;Qi-Chao Shen;Tie-Tao Zhou

School of Materials Science and Engineering,Beihang University,Beijing 100191,China;Vascular Department,Second Affiliated Hospital,Medicine School of Zhejiang University,Hangzhou 310052,China

稀有金属（英文版）

[1]Bao-Liang Wu;Bing Chen;Cheng-Wei Wang;Jing-Ye Jiao;Qi-Chao Shen;Tie-Tao Zhou-.Corrosion behavior of a novel Mg-13Li-X alloy with different grain sizes by rapid solidification rate)[J].稀有金属（英文版）,2022(09):3197-3204

13Li,solidi,Icor

Corrosion,behavior,novel,Mg,different,grain,sizes,by,rapid,solidification,rate,degradable,biomaterials,higher,dation,alloys,physiological,environment,main,challenge,implant,applications,In,order,try,overcome,this,limitation,present,work,was,dedicated,studying,corrosion,fabricated,process,RSP,special,immersed,Hank,balanced,salt,solution,HBSS,influence,immersion,analyzed,ray,diffraction,scanning,electron,microscopy,complemented,electrochemical,techniques,such,potentiodynamic,polarization,curves,impedance,spectroscopy,were,applied,Microstructural,characterization,indicates,that,mean,are,decreasing,By,contrast,conventional,cast,has,average,about,results,test,sample,most,positive,potential,Ecorr,minimum,current,after,Therefore,finest,improve,resistance,reduce,its,density,increase,However,because,weak,layer,product,which,consists,does,not,afford,strong,protection,becomes,worse,longer,periods

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