Search

Your search keyword '"Shan, Dayong"' showing total 166 results
Start Over Author "Shan, Dayong"
166 results on '"Shan, Dayong"'

44. Comparison of the corrosion behavior of AM60 Mg alloy with and without self-healing coating in atmospheric environment.

Author

Song, Yingwei, Liu, Dan, Tang, Weineng, Dong, Kaihui, Shan, Dayong, and Han, En–Hou

Subjects
SELF-healing materials, MILD steel, SURFACE coatings, PROBLEM solving, ALLOYS, RAINWATER
Abstract

Coatings on the surface of Mg alloys are inevitably damaged during their practical applications, and corrosion can easily initiate from the damaged areas to accelerate the failure of Mg parts. A dual self-healing coating has already been developed to solve this problem in our previous work. Considering the practical application of this coating, it is necessary to investigate its service behavior in atmospheric environment. Thus, the corrosion behavior of AM60 Mg substrate with and without the self-healing coating was compared in Shenyang industrial atmospheric environment. The results show that the enrichment of sediments and rainwater on the scratch areas can accelerate the corrosion of the exposed Mg substrate. The inhibitors can be released from the damaged coating to inhibit corrosion. The dual self-healing coating shows better inhibition ability to narrow scratches due to the higher inhibitor concentration and less resumption. Also, the coating with wide scratches displays enough inhibition ability as well. The dual self-healing coating is a good alternative for Mg alloy parts in the practical applications. [ABSTRACT FROM AUTHOR]

Published
2021
Full Text
View/download PDF

50. Structure and formation mechanism of phosphate conversion coating on die-cast AZ91D magnesium alloy

Author

Wei Ke, En-Hou Han, Shan Dayong, and Wan-qiu Zhou

Subjects
Materials science, Magnesium, General Chemical Engineering, Metallurgy, chemistry.chemical_element, General Chemistry, engineering.material, Phosphate, Phosphate conversion coating, Corrosion, chemistry.chemical_compound, Chemical engineering, Coating, chemistry, Conversion coating, engineering, General Materials Science, Magnesium alloy, Dissolution
Abstract

Phosphate conversion coating, which is considered as all alternative to chromium conversion coating for improving the corrosion resistance of die-cast AZ91D magnesium alloy is studied. The structure and formation mechanism of the coating was investigated in details using ESEM/EDX, XRD, EPMA, ICP and electrochemical method. It was found that the conversion coating was composed of complex phosphate containing magnesium and aluminum and showed amorphous structure. The thickness of the coating was about 10 mu m. A possible formation mechanism for phosphate conversion coating was proposed. Local pH rise due to the evolution of hydrogen in the vicinity of micro-cathode attributed to the movement of hydrolysis reaction balance for manganese dihydro phosphate in treating solution and resulted in the phosphate coating precipitated oil metal surface. Initial depositing position was related to the microstructure of substrate. Galvanic effect between alpha phase and beta phase caused the flower-like phosphate nuclei preferential depositing oil beta phase. Ball-like phosphate nuclei deposited mainly in alpha phase interior due to the micro-galvanic effect within alpha phase. The primary alpha phase was removed from the metal matrix due to the corrosion dissolution, which suggested the anodic dissolution mechanism during phosphate conversion coating growth. The inner stress in dried film resulted in random distribution of the network micro-cracks oil film surface, the crack site did not correspond to beta phase. (C) 2007 Elsevier Ltd. All rights reserved.

Published
2008

Catalog

Books, media, physical & digital resources
See catalog results