Effect of Ca Content on the Mechanical Properties and Corrosion Behaviors of Extruded Mg–7Li–3Al Alloys

Abstract

The effect of Ca addition on the microstructure, mechanical properties, and corrosion behaviors of the extruded Mg–7Li–3Al alloys was investigated. The results showed that the extruded Mg–7Li–3Al–xCa alloys consisted of α-Mg (hcp) + β-Li (bcc) matrix phases and Al2Ca. With increasing Ca content, the amount and morphology of the Al2Ca phase changed significantly. The grains of the extruded Mg–7Li–3Al–xCa alloys were refined by dynamic recrystallization during the extrusion process. The tensile tests results indicated that the extruded Mg–7Li–3Al–0.4Ca alloy exhibited favorable comprehensive mechanical properties; its ultimate tensile strength was 286 MPa, the yield strength was 249 MPa, and the elongation was 18.7%. The corrosion results showed that this alloy with 0.4 wt.% Ca addition exhibited superior corrosion resistance, with a corrosion potential Ecorr of −1.48742 VVSE, attributed to the formation of protective Al2Ca phases.

Enhanced Degradability of Mg-2Gd Alloy by Alloying Cu

“…Figure 10 showed various Mg alloys' EL and corrosion rate (in NaCl solutions). [64][65][66][67][68][69][70][71][72][73][74] Although the Mg-Gd-Zn alloys prepared by Srinivasan et al 72 showed a relative fast corrosion rate about 30 mm•y −1 , the EL was not acceptable. In contrast, in spite of better EL shown in Mg-Li-Al(-Ca) alloys (bigger than 15%), 74 the corrosion rates were relatively slower.…”

“…[64][65][66][67][68][69][70][71][72][73][74] Although the Mg-Gd-Zn alloys prepared by Srinivasan et al 72 showed a relative fast corrosion rate about 30 mm•y −1 , the EL was not acceptable. In contrast, in spite of better EL shown in Mg-Li-Al(-Ca) alloys (bigger than 15%), 74 the corrosion rates were relatively slower. To our best knowledge, only very few researches managed to obtain Mg alloys with both high degradation rate and plasticity.…”

“…All the Mg-2Gd-xCu alloys exhibited characteristics of local corrosion but alloys containing more Cu were corroded more seriously due to the profuse Mg 2 Cu, refined grain size, and much weaker rare earth texture. 64 Mg-Dy, 69 Mg-Gd-Zn, 72 Mg-Zn-Zr(-La), 66 Mg-Al-Zn, 68 Mg-Zn-Mn(-Ca), 73 Mg-Zn-La, 70 Mg-Li-Al-Zn-Nd-Zr, 71 Mg-Y-Nd, 65 Mg-Li-Al(-Ca), 74 Mg-Gd-Ni 13 and Mg-Gd(-Cu) in this work.…”

“…Figure10. EL and corrosion rate of different Mg alloys: Mg-Al(−Sm),64 Mg-Dy,69 Mg-Gd-Zn,72 Mg-Zn-Zr(-La),66 Mg-Al-Zn, 68 Mg-Zn-Mn(-Ca),73 Mg-Zn-La,70 Mg-Li-Al-Zn-Nd-Zr,71 Mg-Y-Nd,65 Mg-Li-Al(-Ca),74 Mg-Gd-Ni13 and Mg-Gd(-Cu) in this work.…”

Mg-Ca0.3 Electrochemical Activity Exposed to Hank’s Physiological Solution and Properties of Ag-Nano-Particles Deposits

“…In a solid solution its percentage can reach up to 1.34 wt.% according to the binary phase diagrams of Mg-Ca [28,50]. It has been reported that the addition of Ca in Mg alloys improves their mechanical properties and diminishes their corrosion activity [51,52]. Mg-Ca alloys, as a class of novel biodegradable magnesium alloys, have been recommended in the context of medical implants [53], with the advantage of a density like that of human bone [2,54].…”