# CNN-Based Ti-6242 Impeller Forging Process Design for Uniform Strain Distribution
## 4 Result and Discussion
### Validation of Improved Forging Process Design Method
When the initial temperature was varied as shown in Figure 13, the maximum height \(H\) did not change when the initial temperature was increased from 850 \({}^{\circ}\)C to 900 \({}^{\circ}\)C, but decreased by 3% when it was increased to 1000 \({}^{\circ}\)C. The maximum radial distance \(L\) did not change when the initial temperature was increased from 850 \({}^{\circ}\)C to 900 \({}^{\circ}\)C, but increased by 3% when it was increased to 1000 \({}^{\circ}\)C. Additionally, the maximum angles, \(\theta_{1}\) and \(\theta_{2}\), decreased by 49% and 8%, respectively, when the temperature was changed from 850 \({}^{\circ}\)C to 900 \({}^{\circ}\)C, but showed an increasing trend of 69% and a decreasing trend of 11%, respectively, when the temperature was changed from 900 \({}^{\circ}\)C to 1000 \({}^{\circ}\)C. Consequently, an inverse correlation was observed between the temperature and the maximum height \(H\), as well as angle \(\theta_{2}\), which means that the increase in temperature resulted in a decrease in both the maximum height \(H\) and angle \(\theta_{2}\). However, no consistent trend was observed for the maximum height \(H\), maximum radial distance \(L\), and angle \(\theta_{2}\) with respect to changes in temperature. As shown in Figure 14, when modifying the friction coefficient, the maximum height \(H\) increased by 2% when the friction coefficient was increased from 0.1 to 0.2, but it decreased again by 2% when the friction coefficient was increased from 0.2 to 0.3. The maximum radial distance \(L\) decreased by 1% when the friction coefficient was increased from 0.1 to 0.2, but increased by 2% when the friction coefficient was increased from 0.2 to 0.3. The maximum slope angles \(\theta_{1}\) and \(\theta_{2}\) decreased by 32% and 5%, respectively, when the friction  
Figure 14: Upset shapes of Impeller design II after deduction according to friction coefficient changes, with temperatures set to 900 \({}^{\circ}\)C; (a) \(\mu\) = 0.1; (b) \(\mu\) = 0.2; (c) \(\mu\) = 0.3. As the friction coefficient increases, the slope angles, \(\theta_{1}\) and \(\theta_{2}\), tend to decrease, but the maximum height \(H\) and the maximum radial distance \(L\) do not consistently show an increase or decrease with an increase in the friction coefficient. Figure 13: Upset shapes of Impeller design II after deduction according to temperature changes, with friction coefficients set to 0.3; (a) \(T\) = 850 \({}^{\circ}\)C; (b) \(T\) = 900 \({}^{\circ}\)C; (c) \(T\) = 1000 \({}^{\circ}\)C. As the initial temperature increases, the angle \(\theta_{2}\) tends to decrease, but the maximum height \(H\), angle \(\theta_{1}\) and the maximum radial distance \(L\) do not show consistent increases or decreases with increasing initial temperature. coefficient was increased from 0.1 to 0.2, and by 30% and 7%, respectively, when the friction coefficient was increased from 0.2 to 0.3. Overall, when the friction coefficient was changed, the slope angles \(\theta_{1}\) and \(\theta_{2}\) decreased as the friction coefficient increased. However, in for \(H\) and \(L\), we could not see a consistent increasing or decreasing trend as the friction coefficient increased. Based on the shape derived from Figures 13 and 14, when the upsetting stroke was derived using the upsetting stroke design guidelines in Section 3.3, the result was as shown in Figure 15. In Figure 15a, when the initial temperature was changed, the upsetting stroke remained the same, at 77 mm, when the temperature was changed from 850 \({}^{\circ}\)C to 900 \({}^{\circ}\)C, but increased by 1 mm to 78 mm when the temperature was increased to 1000 \({}^{\circ}\)C. In Figure 15b, when the friction coefficient was changed, increasing it from 0.1 to 0.2 caused the upsetting stroke to decrease by 1 mm from 77 mm to 76 mm, but when increased to 0.3, the upsetting stroke increased again to 77 mm.