No. | Parameter of surface roughness | Equation of trend line | Coefficient of determination R2 |
1 | Ra | y = 5E−08x2 + 6E−05x + 0.069 | 0.995 |
2 | Rz | y = 1E−06x2 + 1.261 | 0.991 |
3 | Rt | y = 4E−07x2 + 0.380 | 0.983 |