Oxidation Behaviour of WE54 and Elektron 21 Magnesium Alloys

Abstract

In the present study, the isothermal early oxidation behaviour of the WE54 and Elektron 21 alloys were studied at a temperature of 773 K in pure O2 up to 150 min. The results showed that the oxidation kinetics depending on the chemical composition and microstructure of the investigated alloys. The oxidation kinetics of these alloys in as-cast and T6 conditions obtained a parabolic law, while in supersaturated state these alloys exhibited a linear kinetics. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses indicated that an oxide film, composed of MgO and (Y,Dy)2O3 in WE54 alloy and (Nd,Gd)2O3 in Elektron 21 alloy, had been formed.

Corrosion of magnesium alloys: the role of alloying

“…3), there is ample information in the literature concerning the microstructures developed, 40–47 and hence our main focus herein is to present their corrosion kinetics in respect to the main microstructural constituents. Mechanical properties will not be covered herein, however, the authors note that the group of high(er) strength Mg-alloys (AE44, WE54, and ZK60) possess the presence of precipitates including Al 11 RE 3 , Al 10 RE 2 Mn 7 , Al 2 RE, 47 Mg x RE y , 44 and MgZn 2 , 48 with improved mechanical properties at the expense of reduced corrosion performance. 49 Taking the finite commercial alloys as examples, the microstructural, and hence electrochemical, heterogeneity requires the quantification of microstructure as a requisite effort in the rationalisation of corrosion performance.…”

“…3), there is ample information in the literature concerning the microstructures developed, [40][41][42][43][44][45][46][47] and hence our main focus herein is to present their corrosion kinetics in respect to the main microstructural constituents. Mechanical properties will not be covered herein, however, the authors note that the group of high(er) strength Mg-alloys (AE44, WE54, and ZK60) possess the presence of precipitates including Al 11 RE 3 , Al 10 RE 2 Mn 7 , Al 2 RE, 47 Mg x RE y , 44 and MgZn 2 , 48 with improved mechanical properties at the expense of reduced corrosion performance. 49 Taking the finite commercial alloys as examples, the microstructural, and hence electrochemical, heterogeneity requires the quantification of microstructure as a requisite effort in the rationalisation of corrosion performance.…”

The Electrochemical and Immersion Corrosion of Casting Magnesium Alloys Containing Rare Earth Elements

“…Mg 41 Nd 5 and Mg 24 Y 5 [6] phases are observed in the WE43 alloy, Mg 2 Y, Mg 24 Y 5 i Mg 12 YNd [7] in the WE54 alloy and Mg 3 (Nd,Gd) type phase has been found in the EV31A alloy. The volume fraction of the intermetallic phases is similar in all alloys and is equal about 6% [9]. Corrosion resistance of the alloys is attributed to yttrium contain, which in the 3.5% NaCl solution increases corrosion resistance of the magnesium alloys.…”

The reactive element effect on high-temperature oxidation of magnesium

“…The Mg–X–Nd–Zr system, as in WE54 and Electron 21 grades, exhibits the oxidation behaviour, being controlled by both alloy chemistry and heat treatment. 147 Exposures in O 2 at temperature of 500°C led to parabolic kinetics for as-cast and T6 heat-treated states, while for the supersaturated state, a linear law was valid. There was a difference in phase composition of oxides with MgO and (Y,Dy) 2 O 3 being characteristic for WE54 and (Nd, Gd) 2 O 3 , dominating scales on the Electron 21 alloy.…”

“…The Mg-X-Nd-Zr system, as in WE54 and Electron 21 grades, exhibits the oxidation behaviour, being controlled by both alloy chemistry and heat treatment. 147 Exposures in O 2 at temperature of 500uC led to parabolic kinetics for as-cast and T6 heat-treated states, while for the supersaturated state, a linear law was valid.…”