Heat generation in machining: The region where maximum heat is produced due to plastic deformation of the work material is called the

Introduction / Context:
Understanding where heat is generated in cutting helps in selecting cutting parameters, tool materials, and coolants. Heat affects tool wear, surface integrity, and dimensional accuracy.

Given Data / Assumptions:

• Orthogonal cutting model for clarity.
• Three regions of interest: primary shear zone, secondary deformation (friction) zone on rake face, and tertiary zone at tool flank.
• We seek the region of maximum heat generation from plastic deformation.

Concept / Approach:
The primary shear zone (often called the shear zone) is where the chip forms as layers of metal undergo severe plastic shear. Most plastic work—and thus the bulk of heat from deformation—occurs here. The friction zone also generates heat, but it is due to sliding at the tool–chip interface, not primarily plastic deformation.

Step-by-Step Solution:

Verification / Alternative check:
Energy partition studies show a dominant share of mechanical work converting to heat in the shear zone for typical cutting conditions.

Why Other Options Are Wrong:
Friction zone is a major heat source but arises from sliding, not primarily plastic deformation; “work–tool contact zone” is a broad phrase and does not isolate the primary shear region.

Common Pitfalls:
Assuming all heat is from friction; in many metals and conditions, primary shear work dominates.

Final Answer:
shear zone