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论文类型：期刊论文

发表时间：2014-07-01

发表刊物：MATERIALS RESEARCH INNOVATIONS

收录刊物：SCIE、EI、Scopus

卷号：18

页面范围：756-760

ISSN号：1432-8917

关键字：High entropy alloys; Potentiodynamic polarisation; Electrochemical impedance spectra; Surface morphology

摘要：In previous research, AlxCoCrFeNiTi0.5 high entropy alloys with various amounts of aluminium had shown many excellent mechanical performances, but few attempts were made to characterise the corrosion performance. Therefore, the purpose of this study was to investigate that of the AlxCoCrFeNiTi0.5 (x=0, 0.5, 1.0) alloy system in an aqueous solution of 0.5M H2SO4 at room temperature with the analysis of potentiodynamic polarisation scanning, corrosion surface morphology and electrochemical impedance spectra. It was verified that a high content of Al enhanced the corrosion resistance of the alloys by simultaneously increasing the corrosion potential and decreasing the corrosion current density, also restraining the tendency of pitting corrosion. When x=0.5 and 1, the alloys had a better corrosion behaviour compared with 304 stainless steel. The equivalent circuits were obtained from the results of EIS tests. They clearly revealed that the existence of a passive film and the difficulty of the resultant diffusion were both important factors to the electrochemical reaction process. This study also demonstrated that constant potential treatment at 0.75 V clearly enhances the corrosion resistance of the alloys.