High corrosion resistance and weak corrosion anisotropy of an as-rolled Mg-3Al-1Zn (in wt.%) alloy with strong crystallographic texture

Abstract

Combining with electrochemical corrosion measurements, immersion and hydrogen evolution testing performed in 0.9 wt.% NaCl solution at 37 °C, the corrosion resistance of an as-rolled Mg-3%Al-1%Zn alloy before and after a 3% compressive strain along the rolling direction was investigated. Results revealed that the corrosion behavior of differently oriented surfaces of the as-rolled samples with a strong basal texture was obviously different. Among them, the corrosion rate of sample surface with the orientation parallel to the normal direction (ND) of the plate was the fastest, the corrosion rate of sample surface with the orientation parallel to the rolling direction (RD) of the plate took the second place and the corrosion rate of sample surface with the orientation parallel to the transverse direction (TD) was the slowest. After being pre-strained, the activation of a high density of {10–12} twins could remarkably reduce the corrosion rate of surrounding α-Mg matrix and simultaneously weaken the corrosion anisotropy between differently oriented samples. The main reason was that similar to grain boundaries, twin boundaries acted as physical barriers to the corrosion attack. Moreover, the activated twins increased the protectiveness of surface films and then suppressed the micro corrosion couples occurred in twinned grains.

Effect of texture evolution on corrosion resistance of AZ80 magnesium alloy subjected to applied force in simulated body fluid

“…It can be inferred that the corrosion resistance of magnesium alloy may be changed with the evolution of crystal texture caused by applied force. The effect of grain orientation or plastic deformation on the corrosion resistance of magnesium alloys in NaCl solution has been reported by some researchers [11][12][13][14][15]. However, the texture effect of applied force on corrosion resistance of magnesium alloys in physiological environment has not been reported.…”

“…Other is the corrosion effect induced by applied force related to plastic deformation. Plastic deformation process affected the microstructure (such as grain size and dislocation density) and thus changed the corrosion resistance of magnesium alloy [14,15]. The previous work of the author showed that the crystal texture of magnesium alloy was changed when the rolled or extruded magnesium alloy was subjected to applied forces along different material orientations [16,17].…”

Effect of Rolling Treatment on Microstructure, Mechanical Properties, and Corrosion Properties of WE43 Alloy

“…As previously mentioned, the experimental EIS data were fitted by using the zSimWin 3.21 software. The simulated equivalent circuit diagram is shown in Figure 7 c. Among them, R s is the solution resistance, R t is the charge transfer resistance at the electrolyte solution interface, R f is the corrosion product resistance, and CPE d and CPE f , respectively, represent the corrosion product film capacity and galvanic double-layer capacity at the interface between the Mg matrix and the electrolyte solution, and are generally used to characterize the high-frequency capacitor loop [ 23 ]. According to the equivalent circuit, the Nyquist diagrams of the WE43 samples before and after rolling were obtained by using ZsimpWin 3.50 software to obtain the fitted values.…”

Crystallographically Textured Electrodes for Rechargeable Batteries: Symmetry, Fabrication, and Characterization

“…How these microstructural features at the grain scale impact the electrochemical performance largely remains underexplored. For example, the corrosion resistance of a rolled Mg alloy is shown to be dependent more on the density of twin boundaries than on the surface textures . There is substantial room for fundamental research and commercial development by borrowing the metallurgists’ wisdom to interrogate metals’ electrochemical performance in practical batteries.…”