Publication detail

Effect of fluoride on plasma electrolytic oxidation of AZ61 magnesium alloy

NĚMCOVÁ, A. SKELDON, P. THOMPSON, G. PACAL, B.

Czech title

Vliv fluoridu na plazmatickou elektrolytickou oxidaci hořčíkové slitiny AZ61

English title

Effect of fluoride on plasma electrolytic oxidation of AZ61 magnesium alloy

Type

journal article - other

Language

en

Original abstract

Plasma electrolytic oxidation has been carried out on AZ61 magnesium alloy in a silicate–phosphate electrolyte under pulsed current conditions. It is shown that the addition of fluoride to the electrolyte reduced localized corrosion that occurred near Al–Mn intermetallic particles before sparking begins. Such corrosion affected the uniformity of the PEO coating. On the other hand, fluoride ions caused significant loss of coating material during coating growth. Irrespective of the fluoride addition, the coatings contained Mg3(PO4)2, amorphous material and possibly MgO. However, fluoride strongly affected the rate of coating growth and the morphology of the coating. The loss of coating material is suggested to be due to the effects of fluoride ions on the intensity of the discharges and melting of the coating.

Czech abstract

Povrchové zpracování plazmatickou elektrolytickou oxidací (PEO) bylo provedeno na protlačované hořčíkové slitině AZ61 v elektrolytu na bázi křemičitan-fosforečnanu při použití zdroje střídavého proudu a frekvence 50 Hz. Fluorid draselný působil jako inhibitor lokální oxidace v počáteční fázi zpracování, ke které docházelo v blízkosti sekundárních fází Al–Mn. Rovněž přítomnost fluoridu způsobila modifikaci charakteru jiskření, snížení rychlosti tvorby povlaku a změnu morfologie povlaku.

English abstract

Plasma electrolytic oxidation has been carried out on AZ61 magnesium alloy in a silicate–phosphate electrolyte under pulsed current conditions. It is shown that the addition of fluoride to the electrolyte reduced localized corrosion that occurred near Al–Mn intermetallic particles before sparking begins. Such corrosion affected the uniformity of the PEO coating. On the other hand, fluoride ions caused significant loss of coating material during coating growth. Irrespective of the fluoride addition, the coatings contained Mg3(PO4)2, amorphous material and possibly MgO. However, fluoride strongly affected the rate of coating growth and the morphology of the coating. The loss of coating material is suggested to be due to the effects of fluoride ions on the intensity of the discharges and melting of the coating.

Keywords in Czech

hořčíková slitina, plazmatická elektrolytická oxidace, fluorid, koroze

Keywords in English

Magnesium alloy, Plasma electrolytic oxidation, Fluoride, Corrosion

RIV year

2013

Released

29.06.2013

ISSN

0257-8972

Volume

2013

Number

232

Pages from–to

827–838

Pages count

12

BIBTEX


@article{BUT102631,
  author="Aneta {Němcová} and Peter {Skeldon} and George {Thompson} and Bohumil {Pacal},
  title="Effect of fluoride on plasma electrolytic oxidation of AZ61 magnesium alloy",
  year="2013",
  volume="2013",
  number="232",
  month="June",
  pages="827--838",
  issn="0257-8972"
}