Corrosion Behavior of CoCrFeNiTax Alloys in 1 M Sodium Chloride Aqueous Solution

Chun-Huei Tsau; Rong-Wei Hsiao; Tien-Yu Chien

doi:10.3390/ma13225157

Corrosion Behavior of CoCrFeNiTa_x Alloys in 1 M Sodium Chloride Aqueous Solution

Materials (Basel). 2020 Nov 16;13(22):5157. doi: 10.3390/ma13225157.

Authors

Chun-Huei Tsau¹, Rong-Wei Hsiao¹, Tien-Yu Chien¹

Affiliation

¹ Institute of Nanomaterials, Chinese Culture University, Huagang Road, 55, Shilin District, Taipei 11114, Taiwan.

Abstract

This paper investigates the effects of Ta content on the microstructures, hardness and corrosion behavior of as-cast CoCrFeNiTa_x alloys. The results indicate that the addition of Ta can change the microstructures of these alloys to dual-phased structures (FCC + HCP), as well as increasing their hardness. This study uses constant galvanostatic/potentiometric methods to measure the polarization curves of CoCrFeNiTa_0.1, CoCrFeNiTa_0.3 and CoCrFeNiTa_0.5 alloys in deaerated 1 M sodium chloride solution at different temperatures. Electrochemical impedance spectroscopy is also used to analyze these alloys in sodium chloride solution. The results indicate that the CoCrFeNiTa_0.5 alloy has a eutectic structure and the highest hardness. Furthermore, although the CoCrFeNiTa_0.5 alloy has the best corrosion resistance, the CoCrFeNiTa_0.3 alloy has the best pitting resistance among these alloys.

Keywords: CoCrFeNiTax alloys; corrosion; critical pitting temperature; electrochemical impedance spectroscopy; hardness; microstructures; polarization test.