Abstract
Corrosion action and passive mechanism of magnesium alloy in the fluoride solution were studied by means of scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDS), and electrochemistry methods. The results show that an insoluble MgF 2 film is generated on the surface of magnesium alloy activated in the hydrofluoric acid. And the mass of the deposited MgF 2 film may reach a constant value, when the mass ratio of Mg/F on the magnesium alloy surface is fixed at 11.3:1. The activated magnesium alloy gains a ‘passivation state’ in a mixture of sulfuric acid and hydrofluoric acid at a volume ratio of less than 1.2. At the same time the mass of magnesium alloy is maintained as a function of the time. When the ratio is above 1.4, the mass of magnesium alloy rapidly decreases. The passive film formed through adsorption of HF 2 − (or H 2F 3 −, H 3F 4 −) ions by the deposited MgF 2 film can protect the magnesium alloy from corrosion in fluoride solution, but not in non-fluoride solutions. The passive state is maintained for activated magnesium alloy in an acidic sulfuric nickel solution with added fluoride. If fluoride and carbonate are added to the acidic sulfuric nickel solution, a replacement reaction between magnesium alloy and solution takes place.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
More From: Transactions of Nonferrous Metals Society of China
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.