## 3 Results and Discussion
### Mechanical Performance of the Rolled Plates  
The tensile properties of the rolled specimen indicate that rolling initially creates an increase in strength at the expense of elongation to, failure. Plots of tensile behavior for 68% rolled specimens in the rolling direction, transverse direction, and 45\({}^{\circ}\) to rolling show that ultimate tensile stress (UTS) reaches over 330 MPa in each case, as shown in Figure 7a. This was a significant increase from the measured UTS by [PERSON] et al. where UTS values of 254.4 MPa, 297.2 MPa and 279.9 MPa were reported for the Longitudinal, Transverse and 45\({}^{\circ}\) to longitudinal directions, respectively [29]. However, most of the specimens do not reach 10% extension to failure, which was a significant decrease from [PERSON]'s observations. This behavior was not surprising, as other experimental efforts to form magnesium alloys have also reported increased strength and reduced elongation to failure, even after the use of extrusion processes to refine grain structure and improve texture [12]. It was notable that [PERSON] et al. reported noticeable anisotropy between the UTS of the rolling, transverse, and 45\({}^{\circ}\) tensile specimens, over 40 MPa, while the specimens used in this study have less than 10 MPa of variation. This suggests that hot rolling at this point has reduced the tensile anisotropy of the material. Additional rolling appears to lead to an overall reduction in tensile properties and an increase in the apparent anisotropy. The 93% rolled specimens, regardless of direction, all have a slightly lower average UTS and smaller elongation to failure (ETF) than the 68% rolled specimens. Considerably more variation in the mechanical behavior was noticeable. The variation in UTS with tensile direction at the same time increased to nearly 25 MPa. This was still less variation than that observed for the ShAPE extruded material. The plots of these tensile stress-strain curves are shown in Figure 7b. The average yield stress, UTS, and ETF for the 68% and 93% rolled specimens was shown in Table 1. Typically, in ZK60, it has been observed that the yield strength along the rolling direction is approximately 50% lesser than in transverse direction. The strength of the plates at both 68% and 93% reduction showed higher values of strength in both transverse and longitudinal directions with no anisotropy as compared to what has been reported in the literature [42]. Figure 7: (a) Representative tensile stress-strain curves of the ShAPE-processed ZK60 flattened and hot-rolled to 68% reduction. (b) Representative tensile stress-strain curves of the ShAPE-processed ZK60 flattened and hot-rolled to 93% reduction. Plots are shown for loading in the rolling direction (RD), 45\({}^{\circ}\) to the rolling direction (45\({}^{\circ}\)), and the transverse direction (TD). It is important to mention, for example, that while the ZK60 sheets in this work were rolled immediately after heating, the sheets were not held at an elevated temperature for rolling, and the rollers themselves were not heated. A hot plate was used to mitigate heat loss in the Mg sheet during transfer to the rolling mill, but it is conceivable that this cooling causes the sheet to experience significant cold work, especially as the sheet decreases in thickness and cools more rapidly. The rolling temperature, annealing treatment, and reduction per pass may also foreseeably improve sheet performance. Previous experimentation on hot-pressed ZK60 by [PERSON] et al. has shown that at annealing temperatures of 400 \({}^{\circ}\)C, recrystallization occurred in under 1000 s, and in the same time the grain structure coarsened from roughly 2 \(\upmu\)m to 7 \(\upmu\)m [10]. This suggests that the time taken to reheat in this work, five minutes (300 s) at 450 \({}^{\circ}\)C, should have been sufficient to cause significant static recrystallization, but may not have been enough to entirely recrystallize the material.