While machining grey cast iron

Explanation:

Types of chip:

• The chips produced while machining any part depend upon the material of the part and the machining condition.
• The types of chips formed during machining are:
  • Discontinuous chip
  • Continuous chip (without built-up edge)
  • Continuous chip (with a built-up edge)
  • Serrated chip

Discontinuous chips:

• The conditions for forming discontinuous chips are:
  • machining brittle material like grey cast iron (irregular shape and size)
  • ductile but hard and work hardenable (regular shape and size)
  • Large feed rate
  • large depth of cut
  • negative rake angle
  • low cutting speed
  • inadequate cutting fluid.

Continuous chips (without built-up edge):

• The conditions for forming continuous chips without built-up edges are:
  • ductile work material like steel
  • high cutting velocity
  • low feed rate
  • positive rake angle
  • low depth of cut

Continuous chips (with a built-up edge):

• The conditions for forming continuous chips with built-up edges are:
  • Ductile work material
  • medium cutting velocity
  • large feed
  • small rake angle

Serrated chips:

• It is also known as segmented or non‐homogeneous chips which are semi‐continuous chips having low and high shear strain zones.
• Metals with low thermal conductivity and strength that decreases sharply with temperature, such as titanium exhibit this behavior.
• The chips have a sawtooth-like appearance.

Thus, option (1) is the correct answer.