Annealed microstructure dependent corrosion behavior of Ti-6Al-3Nb-2Zr-1Mo alloy  

作　　者：Baoxian Su Liangshun Luo Binbin Wang Yanqing Su Liang Wang Robert O.Ritchie Enyu Guo Ting Li Huimin Yang Haiguang Huang Jingjie Guo Hengzhi Fu 

机构地区：[1]National Key Laboratory for Precision Hot Processing of Metals,School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China [2]Department of Materials Science and Engineering,University of California,Berkeley,CL 94720,USA [3]Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province),School of Materials Science&Engineering,Dalian University of Technology,Dalian,116024,China [4]Department of Materials Science and Engineering,Dalian Maritime University,Dalian 116026,China [5]School of Materials and Chemical Engineering,Heilongjiang Institute of Technology,Harbin 150050,China [6]School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China [7]Yunnan Titanium Industry Co.,Ltd.,Chuxiong 651209,China

出　　处：《Journal of Materials Science & Technology》2021年第3期234-248,共15页材料科学技术（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFB0301201);the Yunnan Rare Metal Materials Genetic Engineering Project(2018ZE013);the National Natural Science Foundation of China(51425402 and 51671073)。

摘　　要：Corrosion resistance of titanium(Ti)alloys is closely connected with their microstructure which can be adjusted and controlled via different annealing schemes.Herein,we systematically investigate the specific effects of annealing on the corrosion performance of Ti-6 Al-3 Nb-2 Zr-1 Mo(Ti80)alloy in 3.5 wt.%NaCl and 5 M HCl solutions,respectively,based on open circuit potential(OCP),potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),static immersion tests and surface analysis.Results indicate that increasing annealing tempe rature endows Ti80 alloy with a higher volume fraction ofβphase and finerαphase,which in turn improves its corrosion resistance.Surface characterization demonstrates thatβphase is more resistant to corrosion thanαphase owing to a higher content of Nb,Mo,and Zr in the former;additionally,the decreased thickness of a phase alleviates segregation of elements to further restrain the micro-galvanic couple effects betweenαandβphases.Meanwhile,the influential mechanisms of environmental conditions on corrosion of Ti80 alloy are discussed in detail.As the formation of a highly compact and stable oxide film on surface,annealed Ti80 alloys exhibit a low corrosion current density(10^(-6)A/cm^(2))and high polarization impedance(10^(6)Ω·cm^(2))in 3.5 wt.%NaCl solution.However,they suffer severe corrosion in 5 M HCl solution,resulting from the breakdown of native oxide films(the conversion of TiO_(2)to aqueous Ti^(3+)),active dissolution of substrate Ti to aqueous Ti^(3+)and existence of micro-galvanic couple effects.Those findings could provide new insights to designing Ti alloys with high-corrosion resistance through microstructural optimization.

关 键 词：Titanium alloys ANNEALING Electrochemical techniques Weight loss Corrosion behavior 

分 类 号：TG146.23[一般工业技术—材料科学与工程]