Enhancing the anti-corrosion performance and biocompatibility of AZ91D Mg alloy by applying roughness pretreatment and coating with in-situ Mg(OH)_(2)/Mg-Al LDH  

作　　者：Zexi Shao Pubo Li Chao Zhang Bintao Wu Chan Tang Mangmang Gao 

机构地区：[1]School of Materials and New Energy,Ningxia Key Laboratory of Photovoltaic Materials,Ningxia University,Yinchuan,750021,PR China [2]Department of Gastroenterology,The Third Xiangya Hospital,Central South University,Changsha,410000,PR China

出　　处：《Journal of Magnesium and Alloys》2024年第6期2520-2533,共14页镁合金学报（英文）

基　　金：the financial support by the Natural Science Foundation of Ningxia(Grant no.2022AAC03099);the Key R&D Project of Ningxia(Grant no.2020BDE03012)。

摘　　要：Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comprised a mixed structure of Mg(OH)_(2)and Mg-Al layered double hydroxides(LDH)and exhibited excellent compactness.Coating film thickness increased with decreasing surface roughness.Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy.Metallographic pretreat-ment influenced the chemical activity of the Mg alloy surface and helped modulate the dissolution rate of the Mg_(17)Al_(12)phase during the hydrothermal procedure.With decreasing roughness of the Mg substrate,the Al^(3+)concentration gradually increased,accelerating the in-situ formation of the Mg(OH)_(2)/LDH composite coating and improving its crystallinity.A thick and dense Mg(OH)_(2)/LDH coating was synthesized on the Mg substrate with the least roughness,substantially improving the corrosion resistance of the AZ91D alloy.The lowest corrosion current density((5.73±2.75)×10^(−8)A·cm^(−2))was achieved,which was approximately three orders of magnitude less than that of bare AZ91D.Moreover,the coating demonstrated biocompatibility with no evident cytotoxicity,cellular damage,and hemolytic phenomena.This study provides an effective method for preparing coatings on Mg alloy surfaces with excellent corrosion resistance and biocompatibility.

关 键 词：Magnesium alloy ROUGHNESS Corrosion resistance Layered double hydroxides BIOCOMPATIBILITY 

分 类 号：R318.08[医药卫生—生物医学工程] TG174.4[医药卫生—基础医学]