Direction: In an orthogonal machining operation:
Uncut thickness = 0.5 mm
Cutting speed = 20 m/min
Rake angle = 15°
Width of cut = 5 mm
Chip thickness = 0.7 mm
Thrust force = 200 N
Cutting force = 1200 N
Assume Merchants theory.
-
The coefficient of friction at the tool-chip interface is
-
- 0.23
- 0.46
- 0.85
- 0.95
Correct Option: B
From Merchant’s theory,
| 2φ + λ − α = | , | |
| 2 |
where, λ =friction angle
λ = 24.6º
∴ μ = tan λ = 0.457
