## 3 Results and Discussion
These samples are separately highlighted as \"inconsistent\" in Figure 6. Additionally, an example of the inconsistent transformation behavior described above is given in Figure 7.  
Figure 5: Differential scanning calorimetry (DSC) test performed on the Cu-Al-Mn alloy (sample 16 in Table 2). Figure 6: Ratio of the average measured concentrations of Mn and Al within each sample, sorted according to increasing ratio values. The sensitivity of manganese to oxidation at high temperatures has presented an issue for the Cu-Al-Mn SMA fabrication since the initial casting process, as mentioned in the section on alloy fabrication. In Figure 8, the Cu-Al-Mn sheet samples were presented according to their manganese content and the applied thermomechanical treatment path. The first group of samples, from 1 to 9, present with the highest reduction in manganese content. This group of samples was obtained by fully hot rolling the initial ingot of \(\sim\)10 mm thickness down to a thickness of 0.4 mm. The loss of manganese, and consequently the loss of SME, within this group of samples was attributed to a combination of the very low sample thickness and high temperatures (900 \({}^{\circ}\)C) between each rolling pass along with the rolling pressure itself. In contrast, the second group of samples, 10 to 13, which like the previous was obtained from the same ingot, was treated by hot rolling from the initial \(\sim\)10 mm thickness down to 2 mm. In this case, the reduction in manganese content was drastically lower than in the previous group with the largest difference being almost \(\sim\)2.25% at. of Mn. Furthermore, the effect of high temperatures in the later phases of rolling, between 2 and 0.4 mm, is further highlighted by the manganese content and SME effect found in the third group of samples, 14 to 20, which was treated with hot rolling down to 2 mm and subsequently cold-rolled the rest of the way to 0.4 mm. In the case of this group, the reduction, or the lack thereof, is comparable to that of the second group of samples. The final two groups of samples were both subjected to a combination of hot and cold rolling in the same way as the third group. However, in addition to these thermomechanical treatments, they were also thermally treated to increase the relative grain size within the sheets. Another significant difference is that while these samples were obtained using the same thermomechanical process as the previous sample groups, with the exception of the grain growth treatment, they came from the second ingot of the Cu-Al-Mn alloy. The samples within these two groups show inconsistent shape memory effect performance, which is in line with their estimated Mn/Al ratios of 0.57, 0.57, and 0.59, respectively. The samples can be found in Figure 6, where they are numbered as samples 21, 14, and 11, respectively. However, the second ingot from which the samples were derived had an estimated average manganese concentration of 10.43% at and a Mn/Al ratio of 0.59. Since these initial values are quite similar to the manganese concentration and Mn/Al ratio reported for the final samples in Figures 6 and 8, it is challenging to assess the impact of the grain growth thermomechanical treatment on the shape memory effect. Therefore, a more in-depth investigation is necessary for samples with this thermomechanical treatment history. Figure 7: DSC analysis performed on a sample (sample 10 in Figure 6) of Cu-Al-Mn showing inconsistent phase transformation performance. As previously mentioned, the raw materials used in the casting process of the Cu-Al-Mn SMA ingot, specifically copper, contained trace amounts of phosphorus. During the EDX analysis of the Cu-Al-Mn sheets obtained at the end of their respective thermomechanical treatment paths, in a number of them, traces of phosphorus were detected, ranging from 0.04 up to 0.27% at.