Structure and Corrosion Resistance of Fluoride Coating Prepared on Magnesium Material

abstrakt

angličtina

Fluoride conversion coatings are perspective surface treatments for reducing corrosion rate of magnesium and Fluoride conversion coatings are perspective surface treatments for reducing corrosion rate of magnesium and its alloys. This work focuses on the preparation of fluoride conversion coating on magnesium material prepared by powder metallurgy. The base material was prepared by compacting powder magnesium into cylinders 20 mm in diameter and 5 mm thick using 400 MPa of uniaxial pressure. The green compacts were sintered in argon atmosphere at 600 °C for 12h. The coating was prepared by dipping the magnesium materials in molten Na[BF4] salt at 430 °C, the preparation times were 1, 2, 4 and 8 h. The effect of fluoride coating preparation time on thickness and structure of the coating was investigated by mainly two methods. Corrosion resistance was measured by potentiodynamic polarisation in NaCl solution, the structure and thickness of the coating was measured by SEM-EDS (Scanning electron Microscope – Energy Dispersive Spectroscopy) method. The corrosion current decreased significantly with increasing preparation time of the coating. This finding is in correlation with SEM-EDS observation, which confirmed thicker coating layer with increasing preparation time. The structure of the coating was not uniform; however, the coating was predominantly formed on the surface of the individual powder particles from which the base material was formed.

Magnesium; Powder metallurgy; Corrosion; Fluoride conversion coatings

BŘEZINA, M.; KOBZINKOVÁ, E.; BUCHTÍK, M.; DOSKOČIL, L.

21. 5. 2025

TANGER Ltd.

Ostrava

978-80-88365-26-6

Abstracts, Metal 2025

1st edition

1

58

58

86