*Effect of ECAE Die Angle on Microstructure Mechanical Properties and Corrosion Behavior… DOI: http://dx.doi.org/10.5772/intechopen.94150*

(Ecorr) shifted to −1.536 VSCE and −1.453 VSCE after two and four ECAP passes which are considerably nobler in comparison with the as-received alloy (−1.540 VSCE). However, the corrosion potential increases with the grain refinement after ECAE in the alloy. Also, the corrosion current density (Icorr) of 2P and 4P ECAPed AZ91 Mg alloy was 0.0173 mA/cm2 and 0.0053 mA/cm2 respectively, which is lesser than that of as-received AZ91 Mg alloy (0.0263 mA/cm2 ). The obtained results revealed that the ECAPed Mg sample after 4 passes has nobler corrosion potential and lower current density when compared with as-received and ECAPed-2P. Therefore, ECAE increased the corrosion resistance of Mg alloy this is due to grain refinement and distribution of secondary phases, which is shown in OM and SEM microstructure in **Figure 16**. Similarly, Shahar et al. [32] explored that the grain refinement and secondary phase distribution through ECAP improves the corrosion resistance of Mg alloys.
