Corrosion behavior of Cu-Al-Mn-Zn-Zr shape memory alloy in NaCl solution  

Cu-Al-Mn-Zn-Zr形状记忆合金在NaCl溶液中的腐蚀行为

作　　者：Mo-yang YIN Zhou LI Zhu XIAO Yong PANG Ya-ping LI Zi-yan SHEN 尹墨阳;李周;肖柱;庞咏;李亚萍;沈紫嫣(中南大学材料科学与工程学院,长沙410083;中南大学粉末冶金国家重点实验室,长沙410083;中南大学有色金属材料科学与工程教育部重点实验室,长沙410083)

机构地区：[1]School of Materials Science and Engineering,Central South University,Changsha 410083,China [2]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [3]Key Laboratory of Non-ferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第4期1012-1022,共11页中国有色金属学报（英文版）

基　　金：financial support from the National Natural Science Foundation of China (51601227);Natural Science Foundation of Hunan Province,China (2018JJ3650);the Project of Innovation-Driven Plan and the Project of State Key Laboratory of Powder Metallurgy,Central South University,China。

摘　　要：The corrosion behavior of a copper-based shape memory alloy(Cu-Al-Mn-Zn-Zr) in 3.5 wt.% Na Cl solution was investigated by means of potentiodynamic polarization measurements, electrochemical impedance spectroscopy(EIS) and X-ray photoelectron spectroscopy(XPS). At the beginning of corrosion, oxidation products formed on the surface of the shape memory alloy and constantly covered the reaction surface, resulting in the decrease of corrosion rate. After 4 d of immersion in NaCl solution, the corrosion product layer became thick and porous, leading to the increase of corrosion rate, and the corrosion reaction mechanism changed from polarization control to diffusion control. The diffusion impedance increased with increasing thickness of the oxide layer for the samples immersed in NaCl solution for 6-15 d. During the whole corrosion process, the reaction mechanism of the alloy changed and the corrosion resistance was improved continuously. The corrosion products mainly contained CuO, ZnO, Al2O3, MnO/Mn2O3, MnO2 and Al(OH)3. Transition of the corrosion products from Cu2O to CuO and Al2O3 to Al(OH)3 occurred during corrosion.通过动态电位极化测量、电化学阻抗谱(EIS)和X射线光电子能谱(XPS)研究铜基形状记忆合金(Cu-Al-Mn-Zn-Zr)在3.5%NaCl(质量分数)溶液中的腐蚀行为。腐蚀开始时,形状记忆合金表面形成的氧化产物不断覆盖合金表面,导致腐蚀速率降低。合金在NaCl溶液中浸泡4 d后,腐蚀产物层变厚及更加疏松多孔,导致腐蚀速率增大,合金表面的腐蚀反应机理由极化控制向扩散控制转变。在NaCl溶液中浸泡6~15 d后,试样的扩散阻抗随氧化层厚度的增加而增大。在整个腐蚀过程中,合金的腐蚀机理发生改变,耐蚀性能持续提高。腐蚀产物主要为CuO、ZnO、Al2O3、MnO/Mn2O3、MnO2和Al(OH)3。腐蚀过程中腐蚀产物由Cu2O转变为CuO,由Al2O3转变为Al(OH)3。

关 键 词：Cu-based shape memory alloy corrosion behavior POLARIZATION diffusion impedance 

分 类 号：TG172[金属学及工艺—金属表面处理]