## 3 Results and Discussion
### Impact of ECAP Processing Factors
#### 3.2.1 Microstructure Evolution
As a result, the 0001-pole  
Figure 5: The (0001) pole viewgraphs obtained from the EBSD data for the (**a**) AA condition and the ECAP-processed using the 90\({}^{\circ}\)-die (**b**,**d**,**f**,**h**,**j**) and 120\({}^{\circ}\)-die (**c**,**e**,**g**,**i**,**k**) for 1P (**b**,**c**), 2A (**d**,**e**), 2 Bc (**f**,**g**), 2C (**h**,**i**), and 4 Bc (**j**,**k**). viewgraph revealed its presence at an angle in relation to the ED, as evidenced by the presence of robust 0001 poles. The 120\({}^{\circ}\) die angle strongly suggested that the texture was a B fiber with its constituents substantially twisted from their optimum placements [64]. Increasing the number of passes to two passes resulted in much weaker crystallographic texture for all the processing routes, as shown in Figure 1:0 The 2A processing displayed double poles; the first was aligned parallel to the ED and the second was twist about 10\({}^{\circ}\) relative to the ED with texture intensity of 9.59 times random (Figure 5d), while 2A processing using the 120\({}^{\circ}\)-die showed a texture intensity of 7.19 times random (Figure 5e). As observed in Figure 5f, the texture achieved by 2 Bc through the ECAP die with 90\({}^{\circ}\) was very similar to the regular B fiber texture [64], with its constituents nearly in their optimal position. Because of the shift in the shear plane's position during the second pass, the shear plane normal (SPN) became aligned with the TD. With regard to the intensity of the texture, it is nearly identical to that following 1P counterpart but with approximately 10.35 times random. Similarly, the texture began to weaken and break apart after 2 Bc via the 120\({}^{\circ}\)-die, as evidenced by the 0001-pole viewgraph (Figure 5g), whereas a larger number of slip systems became active after the second pass with ECAP, which explained this phenomenon. The 2 Bc displayed a texture intensity of 11.66 times random, as depicted in Figure 5g. Furthermore, 2C through the 90\({}^{\circ}\)-die experienced the weakest texture with a maximum texture intensity of 5.80 times random, as shown in Figure 5h. On the other hand, 2C processing through the 120\({}^{\circ}\)-die displayed much higher texture intensity (14.68 times random) compared to its 2A and 2 Bc counterparts, as shown in Figure 5i. Bringing the total count of ECAP passes up to 4 Bc using the 90\({}^{\circ}\)-die produced a highly robust texture that was greater than 26.21 times random, and the intense (0001) poles were in alignment in the midpoint of the distance from the transverse direction (TD) to the ED, as shown in Figure 5j. This robust fiber texture that had been seen following 4 Bc might be related to the grain refinement that took place following 1P and 2 Bc, which enabled activating additional slip systems after 4 Bc [70]. However, the ECAP processing for 4 Bc through the 120\({}^{\circ}\)-die had oriented the intense 0001 poles so that they were perpendicular to the ED and aligned with the TD (Figure 5k). The texture crystallography of pure Mg that underwent ECAP was studied by [PERSON] and [PERSON] [71]. They used a maximum of 8P at various temperatures and employed route A, which utilized a 90\({}^{\circ}\) angle for its die. According to their findings, after one pass, the strong basal poles revolved 130 degrees about the TD axis to achieve the optimal location for the B fiber, accordingly raising the temperature and the passes until eight failed to substantially alter the texture beyond a minor fluctuation in its intensity. They concluded that this was because the slip deformation mechanism predominated. Checking the pole figures (0001) confirmed that except for 4 Bc through the 90\({}^{\circ}\)-die and 1P through the 120\({}^{\circ}\)-die, all treated texture components were weaker and less intense than in the AA condition (Figure 5). One possible interpretation of this weakening is that the slip mechanism had been activated.