Direction: In an orthogonal cutting experiment, an HSS tool having the following tool signature in the orthogonal reference system (ORS) has been used: 0-10-7-7-10-75-1 Given: Width of cut = 3.6 mm, Shear strength of workpiece material = 460 N/mm²; Depth of cut = 0.25 mm; Coefficient of friction at chip tool interface = 0.7.
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Shear plane angle (in degrees) for minimum cutting force is
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- 20.5
- 28.6
- 24.5
- 32.5
Correct Option: D
α = 10°,
w = 3.6 mm
μ = 0.7
For minimum cutting force,
By using Ernest & Merchant’s theory
2φ + β – α = 90°
φ = 32.50°
τs = 460 N/mm², d = 0.25 mm
ft = fcos ψ
ψ = 90 – 75
ψ = 15°
ft = t1 = cos 15° × 0.2
