New insights into the effect of Tris-HCl and Tris on corrosion of magnesium alloy in presence of bicarbonate,sulfate,hydrogen phosphate and dihydrogen phosphate ions
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第9期
论文作者：Lan-Yue Cui Yan Hu Rong-Chang Zeng Yong-Xin Yang Dan-Dan Sun Shuo-Qi Li Fen Zhang En-Hou Han
文章页码：971 - 986
摘 要：In vitro degradation is an important approach to screening appropriate biomedical magnesium（Mg） alloys at low cost. However, corrosion products deposited on Mg alloys exert a critical impact on corrosion resistance. There are no acceptable criteria on the evaluation on degradation rate of Mg alloys. Understanding the degradation behavior of Mg alloys in presence of Tris buffer is necessary. An investigation was made to compare the influence of Tris-HCl and Tris on the corrosion behavior of Mg alloy AZ31 in the presence of various anions of simulated body fluids via hydrogen evolution, p H value and electrochemical tests.The results demonstrated that the Tris-HCl buffer resulted in general corrosion due to the inhibition of the formation of corrosion products and thus increased the corrosion rate of the AZ31 alloy. Whereas Tris gave rise to pitting corrosion or general corrosion due to the fact that the hydrolysis of the amino-group of Tris led to an increase in solution p H value, and promoted the formation of corrosion products and thus a significant reduction in corrosion rate. In addition, the corrosion mechanisms in the presence of Tris-HCl and Tris were proposed. Tris-HCl as a buffer prevented the formation of precipitates of HCO3-, SO42-,HPO42- and H2PO4- ions during the corrosion of the AZ31 alloy due to its lower buffering p H value（x.x）.Thus, both the hydrogen evolution rate and corrosion current density of the alloy were approximately one order of magnitude higher in presence of Tris-HCl than Tris and Tris-free saline solutions.
Lan-Yue Cui1,2，Yan Hu1,2，Rong-Chang Zeng1,2，Yong-Xin Yang1,2，Dan-Dan Sun1，Shuo-Qi Li1,2，Fen Zhang1,2，En-Hou Han3
1. College of Materials Science and Engineering,Shandong University of Science and Technology2. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology3. National Engineering Centre for Corrosion Control,Institute of Metals Research,Chinese Academy of Sciences
摘 要：In vitro degradation is an important approach to screening appropriate biomedical magnesium（Mg） alloys at low cost. However, corrosion products deposited on Mg alloys exert a critical impact on corrosion resistance. There are no acceptable criteria on the evaluation on degradation rate of Mg alloys. Understanding the degradation behavior of Mg alloys in presence of Tris buffer is necessary. An investigation was made to compare the influence of Tris-HCl and Tris on the corrosion behavior of Mg alloy AZ31 in the presence of various anions of simulated body fluids via hydrogen evolution, p H value and electrochemical tests.The results demonstrated that the Tris-HCl buffer resulted in general corrosion due to the inhibition of the formation of corrosion products and thus increased the corrosion rate of the AZ31 alloy. Whereas Tris gave rise to pitting corrosion or general corrosion due to the fact that the hydrolysis of the amino-group of Tris led to an increase in solution p H value, and promoted the formation of corrosion products and thus a significant reduction in corrosion rate. In addition, the corrosion mechanisms in the presence of Tris-HCl and Tris were proposed. Tris-HCl as a buffer prevented the formation of precipitates of HCO3-, SO42-,HPO42- and H2PO4- ions during the corrosion of the AZ31 alloy due to its lower buffering p H value（x.x）.Thus, both the hydrogen evolution rate and corrosion current density of the alloy were approximately one order of magnitude higher in presence of Tris-HCl than Tris and Tris-free saline solutions.
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