Table 7.
ANOVA—Miniature tube B *.
| Source | Average Surface Roughness (Ra) | Back Wall Dross | ||||||
|---|---|---|---|---|---|---|---|---|
| DF | SS | F | P | DF | SS | F | P | |
| X1: Pulse Fequency, f (Hz) | 1 | 0.01477 | 2.14 | 0.156 | 1 | 0.022 | 0.07 | 0.794 |
| X2: Pulse width, τ (ms) | 1 | 0.086544 | 12.52 | 0.002 | 1 | 0.76 | 2.39 | 0.135 |
| X3: Peak Power, Ppeak (W) | 1 | 0.00044 | 0.06 | 0.803 | 1 | 1.146 | 3.6 | 0.069 |
| X4: Cutting Speed, v (mm/min) | 1 | 0.14007 | 20.26 | 0.000 | 1 | 0.401 | 1.26 | 0.272 |
| X5: Pressure, P (bar) | 1 | 0.05401 | 7.81 | 0.010 | 1 | 3.457 | 10.87 | 0.003 |
| X1X2 | 1 | 0.01165 | 1.68 | 0.206 | 1 | 0.662 | 2.08 | 0.161 |
| X1X4 | 1 | 0.0651 | 9.42 | 0.005 | 1 | 0.206 | 0.65 | 0.428 |
| X1X5 | 1 | 0.03812 | 5.52 | 0.027 | 1 | 0.052 | 0.16 | 0.689 |
| X2X3 | 1 | 0.00794 | 1.15 | 0.294 | 1 | 0.007 | 0.02 | 0.881 |
| X4X5 | 1 | 0.07538 | 10.9 | 0.003 | 1 | 3.0283 | 9.53 | 0.005 |
| Curvature | 1 | 0.4514 | 65.34 | 0.000 | 1 | 85.186 | 267.97 | 0.000 |
| Residual error | 25 | 0.17281 | 25 | 7.9474 | ||||
| Lack of fit | 21 | 0.162285 | 2.94 | 0.153 | 21 | 7.107 | 1.61 | 0.347 |
| Pure error | 4 | 0.010528 | 4 | 0.841 | ||||
* Miniature tube B: Hard drawn 1.8 mm OD and 160 µm wall thickness (p-values below 0.05 are bolded).