this ppt help all the mechanical enginerriing student.

1. CHIPS

2. CONTENTS
• Introduction
• Mechanism of chip formation
• Factors for chip types
• Types of chips
• Chip Breakers

3. INTRODUCTION
 Metal cutting or machining is the process of producing workpiece by
removing unwanted material from a block of metal, in the form of
chips.
 This process is most important because almost all products get their
final shape and size directly or indirectly by machining.
 Its major drawback is that in this process there is a lot of material lost
in the form of chips.

4. MECHANICS OF CHIP FORMATION
 A wedge shaped tool is made to move relative to theworkpiece.
 As the tool makes contact with the workpiece it exerts pressure on it
resulting in compression of the metal near the tool tip.
 This induces shear – type deformation within the metal and it starts
moving upward along the face of the tool.
 As the tool advances this process of shearing goes on increasing and
material is removed.

5. MECHANICS OF CHIP FORMATION

6. CHIP FORMATION IN DUCTILE MATERIALS
• As the tool makes contact with the workpiece it
Results in exerting pressure on the
material in front of it.

7. CHIP FORMATION IN BRITTLE MATERIALS
• CHIP FORMATION IN BRITTLE MATERIALS
Cracks develop in the workpiece near the tool tip.
• This crack results in stress concentration.
• Hence, crack propagation intensity increases and
• the chip detaches itself from the base material.
• This results in a discontinuous, irregular shape and sized chip.

8. FACTORS FOR CHIPTYPES
• Nature of work piece
• Nature of tool
• Dimension of tool
• Feed rate
• Cutting speed
• Cutting environment like temperature, friction, etc
• Friction between tool and work piece.

9. CHIPS TYPES
 Continuous chips
 Discontinuous chips
 Continuous chips with built up edges (BUE)

10. CONTINUOUSCHIPS
• If the metal chips are formed during machining is without
segments i.e. without breakage,than it is called as
continuous types of chips.
• Continuous chips are formed when the ductile
material ismachined with high cutting speed
and minimum friction between the chip and
tool face.

11. DISCONTINUOUS CHIPS
• If the chip is formed during machining is not continuous i.e. formed with
breakage is called discontinuous chips.
• Discontinuous types of chips are formed when hard and brittle
metals like brass, bronze and cast iron is machined.

12. CONTINUOUS CHIP WITH BUILT UP EDGE
 Continuous chips with built up edge is formed by machining ductile
material with high friction at the chip-tool interface.
 It is similar to the continuous types of chips but it is of less
smoothness due to the built up edge.