Wear and Corrosion Resistance of Al0.5CoCrCuFeNi High-Entropy Alloy Coating Deposited on AZ91D Magnesium Alloy by Laser Cladding

Kaijin Huang; Lin Chen; Xin Lin; Haisong Huang; Shihao Tang; Feilong Du

doi:10.3390/e20120915

Wear and Corrosion Resistance of Al_0.5CoCrCuFeNi High-Entropy Alloy Coating Deposited on AZ91D Magnesium Alloy by Laser Cladding

Entropy (Basel). 2018 Nov 30;20(12):915. doi: 10.3390/e20120915.

Authors

Kaijin Huang^{1

2

3

4}, Lin Chen², Xin Lin³, Haisong Huang⁴, Shihao Tang⁴, Feilong Du⁴

Affiliations

¹ State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
² Material Corrosion and Protection Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Zigong 643000, China.
³ State Key Laboratory of Solidification Processing, Northwestern Polytechnic University, Xi'an 710072, China.
⁴ Key Laboratory of Advanced Manufacturing Technology, Ministry of Education, Guizhou University, Guiyang 550025, China.

Abstract

In order to improve the wear and corrosion resistance of an AZ91D magnesium alloy substrate, an Al_0.5CoCrCuFeNi high-entropy alloy coating was successfully prepared on an AZ91D magnesium alloy surface by laser cladding using mixed elemental powders. Optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction were used to characterize the microstructure of the coating. The wear resistance and corrosion resistance of the coating were evaluated by dry sliding wear and potentiodynamic polarization curve test methods, respectively. The results show that the coating was composed of a simple FCC solid solution phase with a microhardness about 3.7 times higher than that of the AZ91D matrix and even higher than that of the same high-entropy alloy prepared by an arc melting method. The coating had better wear resistance than the AZ91D matrix, and the wear rate was about 2.5 times lower than that of the AZ91D matrix. Moreover, the main wear mechanisms of the coating and the AZ91D matrix were different. The former was abrasive wear and the latter was adhesive wear. The corrosion resistance of the coating was also better than that of the AZ91D matrix because the corrosion potential of the former was more positive and the corrosion current was smaller.

Keywords: AZ91D magnesium alloy; corrosion; high-entropy alloy coating; laser cladding; wear.