Influence of Cerium on the Deformation and Corrosion of Magnesium

Abstract

In this study, a new magnesium (Mg) alloy containing 0.4% Ce was developed using the technique of disintegrated melt deposition followed by hot extrusion. The tensile and compressive properties of the developed Mg–0.4Ce alloy were investigated before and after heat treatment with an intention of understanding the influence of cerium on the deformation and corrosion of magnesium. Interestingly, cerium addition has enhanced the strength (by 182% and 118%) as well as the elongation to failure of Mg (by 93% and 8%) under both tensile and compressive loadings, respectively. After heat treatment, under compression, the Mg–0.4Ce(S) alloy exhibited extensive plastic deformation which was 80% higher than that of the as-extruded condition. Considering the tensile and compressive flow curves, the as-extruded Mg–0.4Ce and the heat treated Mg–0.4Ce(S) alloys exhibited variation in the nature and shape of the curves which indicates a disparity in the tensile and compressive deformation behavior. Hence, these tensile and compressive deformation mechanisms were studied in detail for both as-extruded as well as heat treated alloys with the aid of microstructural characterization techniques (scanning electron microscope (SEM), transmission electron microscope (TEM), selective area diffraction (SAD), and X-ray diffraction (XRD) analysis. Furthermore, results of immersion tests of both as-extruded and heat treated alloys revealed an improved corrosion resistance (by ∼3 times in terms of % weight loss) in heat treated state vis-a-vis the as-extruded state.

Nano-ZnO Particles’ Effect in Improving the Mechanical Response of Mg-3Al-0.4Ce Alloy

“…The microhardness of Mg-3Al-0.4Ce alloy is seen to be much higher as compared to that of pure Mg [5] and commercially available AZ31B [11]. This is due to the addition of a rare earth element.…”

“…Furthermore, the solubility of RE metals in Mg is not very high, hence, increase in the content of solute RE concentration reduces strength [4]. The results of literature studies showed that the addition of 0.4% Ce [5] yields the best properties of tensile strength and ductility and no research has been done to study the effect of reinforcement on Mg-Al-Ce alloys. Furthermore, reinforcement with nano-particulates is also another possibility to improve the properties of Mg.…”

Cumulative Effect of Strength Enhancer—Lanthanum and Ductility Enhancer—Cerium on Mechanical Response of Magnesium

“…The secondary phases (Mg 17 La 2 ) were segregated and distributed discontinuously across grains (see Figure 2c,d). Mg 17 La 2 phase had a size of about 1 ± 0.5 µm unlike Mg 17 Ce 2 phase in Mg-0.4Ce alloy whose size was much lower than 1 µm [6]. Further, it is also interesting to note that the Mg 17 La 2 secondary phases with a much higher volume fraction of~0.46 as compared to Mg 17 Ce 2 phase in Mg-0.4Ce alloy (vol.…”

“…The Rare Earths were added in the form of master alloys (Mg-30%RE) with >99% purity obtained from Sunrelier Metal Co. Limited, Pudong, Shanghai, China. Mg-4La-0.4Ce alloy was synthesized using the Disintegrated Melt Deposition technique [6]. The ingot obtained from casting was machined and soaked at 400 • C for 1 hour in a constant temperature furnace before extrusion.…”

“…The results were attributed to an altered texture during dynamic recrystallization through alignment of the c-axis of the grains to a direction which favors non-basal slip, as well as an increase in the stacking fault energy which promotes cross slips [5]. In another investigation, by adopting the Disintegrated Melt Deposition (DMD) technique followed by extrusion, Tekumalla et al [6] obtained the as-extruded Mg-0.4Ce alloy with excellent overall mechanical properties including an improvement in tensile yield strength by 182%, as compared to pure Mg and a tensile ductility of 27%.…”