MECHANICS OF METAL CUTTING


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Friction
Tool
Motion of
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Chip formation
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2.2.3
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Normal and shear stresses
Fundamentals of Machining and Machine Tools
Normal stress
Tangential (shear)
stress
Distance along rake face
C
max
n
E
D
K = n
K
A
B
Sticking F
zone
l1
Slipping zone
l2
ln
Tool
The distribution function of normal stress
= where,
= constant
= constant
= distance from end of chip-tool contact.
If is the normal stress on the rake face at a distance from the end of
contact length.
= max
where,
max = max. normal stress at the cutting edge
= natural contact length between tool and chip.
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Chip
Chip-tool
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Face
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Flank
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Workpiece
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Cylindrical
tool edge
Work-tool interface
55
2.9 CHIP VELOCITY
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Chip
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Vs
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t Tool
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(90° + – )
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Workpiece
90° – B
Velocity diagram
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Fig. 2.16 
­€ ­€ ­€  ­€ ­€  2.10 MACHINING WITH VARIABLE UNCUT CHIP THICKNESS
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ip
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Velocity diagram
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60 2.11.5 Shear Plane Angle
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 2.12 MECHANICS OF TURNING PROCESS
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Cutter
Cutter
Workpiece
Workpiece
Table feed
Table feed
(a) Up-milling
(b) Down-milling
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