Figure 1.
Five-axis milling of sculptured surfaces elements with a curved line contour.
Figure 2.
Effect of unevenly distributed roughness: (a) roughness builds up from the inlet side, (b) roughness builds up from the outlet side.
Figure 3.
Analytical diagrams of tool orientation and tool contact position. (a) Tool orientation, (b) tool contact position.
Figure 4.
Research 3D-CAD model of the turbine blade.
Figure 5.
Structure of the research object.
Figure 6.
Test areas depending on the curvature radius ρ1 and the lead angle α.
Figure 8.
3D profilograph MarSurf GD 120.
Figure 9.
Methodology for measuring surface roughness and topography.
Figure 10.
Influence of the lead angle α and radius of curvature ρ1 on the Ra roughness parameter of the convex (a) and concave (b) surface.
Figure 11.
Effect of the curvature radius ρ1 on the Ra roughness parameter in the machining of the convex surface: (1) α = 4°, (2) α = 7.5°, (3) α = 11°, (4) α = 14.5°, (5) α = 18°.
Figure 12.
Effect of the lead angle α on the Ra roughness parameter in the machining of the convex surface: (1) ρ1 = 30 mm, (2) ρ1 = 122.5 mm, (3) ρ1 = 215 mm, (4) ρ1 = 307.5 mm, (5) ρ1 = 400 mm.
Figure 13.
Effect of the curvature radius ρ1 on the Ra roughness parameter in the machining of the concave surface: (1) α = 7°, (2) α = 11°, (3) α = 15°, (4) α = 19°, (5) α = 23°.
Figure 14.
Effect of the lead angle α on the Ra roughness parameter in the machining of the concave surface: (1) ρ1 = 40 mm, (2) ρ1 = 55 mm, (3) ρ1 = 80 mm, (4) ρ1 = 95 mm, (5) ρ1 = 120 mm.
Figure 15.
Influence of the lead angle α and radius of curvature ρ1 on the Rz roughness parameter of the convex (a) and concave (b) surface.
Figure 16.
Effect of the curvature radius ρ1 on the Rz roughness parameter in the machining of the convex surface: (1) α = 4°, (2) α = 7,5°, (3) α = 11°, (4) α = 14,5°, (5) α = 18°.
Figure 17.
Effect of the lead angle α on the Rz roughness parameter in the machining of the convex surface: (1) ρ1 = 30 mm, (2) ρ1 = 122.5 mm, (3) ρ1 = 215 mm, (4) ρ1 = 307.5 mm, (5) ρ1 = 400 mm.
Figure 18.
Effect of the curvature radius ρ1 on the Rz roughness parameter in the machining of the concave surface: (1) α = 7°, (2) α = 11°, (3) α = 15°, (4) α = 19°, (5) α = 23°.
Figure 19.
Effect of the lead angle α on the Rz roughness parameter in the machining of the concave surface: (1) ρ1 = 40 mm, (2) ρ1 = 55 mm, (3) ρ1 = 80 mm, (4) ρ1 = 95 mm, (5) ρ1 = 120 mm.
Figure 20.
Statement of the measurement results of the parameter Sa of the convex surface of the turbine blade.
Figure 21.
Statement of the measurement results of the parameter Sa of the concave surface of the turbine blade.
Figure 22.
Statement of the measurement results of the parameter Sz of the convex surface of the turbine blade.
Figure 23.
Statement of the measurement results of the parameter Sz of the concave surface of the turbine blade.
Figure 24.
Topography of the convex surface when changing the curvature radius for the lead angle α = 4°.
Figure 25.
Topography of the convex surface when changing the curvature radius for the lead angle α = 11°.
Figure 26.
Topography of the convex surface when changing the curvature radius for the lead angle α = 18°.
Figure 27.
Topography of the concave surface when changing the curvature radius for the lead angle α = 7°.
Figure 28.
Topography of the concave surface when changing the curvature radius for the lead angle α = 15°.
Figure 29.
Topography of the concave surface when changing the curvature radius for the lead angle α = 23°.
Table 1.
Chemical composition of the Inconel 718 alloy in% of elements.
| Fe | Cr | Co | Mo | W | Nb | Al | Ti | C | B | Zr | Ni |
---|
IN718 | 18. | 19 | - | 3 | - | 5.1 | 0.5 | 0.95 | 0.05 | 0.04 | - | 525 |
Table 2.
Main mechanical and physical properties of Inconel 718 nickel alloy.
Tensile Strength (MPa) | Yield Strength (MPa) | Elastic Modulus (GPa) | Elongation (%) | Density (g/cm3) |
---|
1330 | 1120 | 220 | 23% | 8.2 |
Table 3.
Dimensions characteristic for the test object.
| Description |
---|
Input variables | X1 | Lead angle α |
X2 | Curvature radius ρ1 |
Output variables | Y1 | 2D and 3D surface roughness parameters |
Constant factors | C1 | Machine tool |
C2 | Material |
C3 | Toroidal cutter |
Limitation | O1 | Minimum lead angle αmin |
Table 4.
Machining conditions.
No. | Parameters | Convex Surface Machining | Concave Surface Machining |
---|
1. | ap [mm] | 0.25 | 0.25 |
2. | ae [mm] | 1.5 | 1.5 |
3. | fz [mm/tooth] | 0.26 | 0.26 |
4. | vc [m/min] | 40 | 40 |
5. | ρ1 [mm] | ρ1 ∈ <30 ÷ 400> | ρ1 ∈ <40 ÷ 120> |
6. | α [°] | α ∈ <4 ÷ 18> | α ∈ <7 ÷ 23> |
Table 5.
Studies’ plan matrix PS/DK 32.
Test Number | Standardized Variables | Squares | Interactions |
---|
x0 | x1 | x2 | x12 | x22 | x1 × 2 |
---|
1 | + | + | + | + | + | + |
2 | + | + | 0 | + | 0 | 0 |
3 | + | + | - | + | + | - |
4 | + | 0 | + | 0 | + | 0 |
5 | + | 0 | 0 | 0 | 0 | 0 |
6 | + | 0 | - | 0 | + | 0 |
7 | + | - | + | + | + | - |
8 | + | - | 0 | + | 0 | 0 |
9 | + | - | - | + | + | + |
Table 6.
Studies’ plan for the convex and concave surface of the turbine blade.
Test Number | Convex Surface | Concave Surface |
---|
x1(α) | x2(ρ1) | x1(α) | x2(ρ1) |
---|
1 | 18 | 400 | 23 | 120 |
2 | 18 | 215 | 23 | 80 |
3 | 18 | 30 | 23 | 40 |
4 | 11 | 400 | 15 | 120 |
5 | 11 | 215 | 15 | 80 |
6 | 11 | 30 | 15 | 40 |
7 | 4 | 400 | 7 | 120 |
8 | 4 | 215 | 7 | 80 |
9 | 4 | 30 | 7 | 40 |