Thermal and Mechanical Processing
Materials Science · FE Reference Handbook section
Handbook notes for this section
Definitions and conditions exactly as the handbook states them.
- Cold working (plastically deforming) a metal increases strength and lowers ductility.
- Raising temperature causes (1) recovery (stress relief), (2) recrystallization, and (3) grain growth. Hot working allows these
- processes to occur simultaneously with deformation.
- Quenching is rapid cooling from elevated temperature, preventing the formation of equilibrium phases.
Core formulas for this FE topic
Definitions, applicability, units, assumptions and worked examples for each relation.
This section is conceptual; there are no equations to memorise.
Worked exam-style examples
The four ways this section is written on the real exam — thoughts first, then equations, then substitution.
An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.7000 in^2; final area (Af) = 2.8500 in^2, determine the percent cold work (CW) in %.
Given
Find
percent cold work (CW), in %
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for CW:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
CW = 39.3617\ \text{%}Step 6 — Check: returning CW = 39.3617 % to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 78.7234 — kept a factor of two that cancels in the correct rearrangement.
- 19.6809 — dropped that same factor in the other direction.
- 43.2979 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 3.8500 in^2; percent cold work (CW) = 58.2000 %, determine the final area (Af) in in^2.
Given
Find
final area (Af), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for Af:
Step 3 — List the givens: original area (A0) = 3.8500 in^2, percent cold work (CW) = 58.2000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Af = 1.6093\ \text{in^2}Step 6 — Check: returning Af = 1.6093 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 3.2186 — kept a factor of two that cancels in the correct rearrangement.
- 0.8046 — dropped that same factor in the other direction.
- 1.7702 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 3.4000 in^2; percent cold work (CW) = 68.7000 %, determine the original area (A0) in in^2.
Given
Find
original area (A0), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for A0:
Step 3 — List the givens: final area (Af) = 3.4000 in^2, percent cold work (CW) = 68.7000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
A_{0} = 10.8626\ \text{in^2}Step 6 — Check: returning A0 = 10.8626 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 21.7252 — kept a factor of two that cancels in the correct rearrangement.
- 5.4313 — dropped that same factor in the other direction.
- 11.9489 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.9500 in^2; final area (Af) = 1.3500 in^2, determine the percent cold work (CW) in %.
Given
Find
percent cold work (CW), in %
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for CW:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
CW = 72.7273\ \text{%}Step 6 — Check: returning CW = 72.7273 % to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 145.5 — kept a factor of two that cancels in the correct rearrangement.
- 36.3636 — dropped that same factor in the other direction.
- 80.0000 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 1.2500 in^2; percent cold work (CW) = 86.6000 %, determine the final area (Af) in in^2.
Given
Find
final area (Af), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for Af:
Step 3 — List the givens: original area (A0) = 1.2500 in^2, percent cold work (CW) = 86.6000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Af = 0.1675\ \text{in^2}Step 6 — Check: returning Af = 0.1675 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 0.3350 — kept a factor of two that cancels in the correct rearrangement.
- 0.0838 — dropped that same factor in the other direction.
- 0.1843 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 1.8000 in^2; percent cold work (CW) = 38.8000 %, determine the original area (A0) in in^2.
Given
Find
original area (A0), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for A0:
Step 3 — List the givens: final area (Af) = 1.8000 in^2, percent cold work (CW) = 38.8000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
A_{0} = 2.9412\ \text{in^2}Step 6 — Check: returning A0 = 2.9412 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 5.8824 — kept a factor of two that cancels in the correct rearrangement.
- 1.4706 — dropped that same factor in the other direction.
- 3.2353 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 2.2500 in^2; final area (Af) = 3.4500 in^2, determine the percent cold work (CW) in %.
Given
Find
percent cold work (CW), in %
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for CW:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
CW = -53.3333\ \text{%}Step 6 — Check: returning CW = -53.3333 % to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- -106.7 — kept a factor of two that cancels in the correct rearrangement.
- -26.6667 — dropped that same factor in the other direction.
- -58.6667 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
A materials technician computes the percent cold work applied during thermal and mechanical processing. Given original area (A0) = 1.8000 in^2; percent cold work (CW) = 88.7000 %, determine the final area (Af) in in^2.
Given
Find
final area (Af), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except Af is given, so isolate Af symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for Af:
Step 3 — List the givens: original area (A0) = 1.8000 in^2, percent cold work (CW) = 88.7000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
Af = 0.2034\ \text{in^2}Step 6 — Check: returning Af = 0.2034 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 0.4068 — kept a factor of two that cancels in the correct rearrangement.
- 0.1017 — dropped that same factor in the other direction.
- 0.2237 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
The thermal and mechanical processing route reduces the cross-sectional area of the bar stock. Given final area (Af) = 2.0000 in^2; percent cold work (CW) = 49.4000 %, determine the original area (A0) in in^2.
Given
Find
original area (A0), in in^2
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except A0 is given, so isolate A0 symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for A0:
Step 3 — List the givens: final area (Af) = 2.0000 in^2, percent cold work (CW) = 49.4000 %.
Step 4 — Substitute the given values:
Step 5 — Evaluate:
A_{0} = 3.9526\ \text{in^2}Step 6 — Check: returning A0 = 3.9526 in^2 to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 7.9051 — kept a factor of two that cancels in the correct rearrangement.
- 1.9763 — dropped that same factor in the other direction.
- 4.3478 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing
An engineer specifies the thermal and mechanical processing schedule for a wire-drawing operation. Given original area (A0) = 4.7000 in^2; final area (Af) = 0.4000 in^2, determine the percent cold work (CW) in %.
Given
Find
percent cold work (CW), in %
Start with the thinking
- The governing relation printed in this handbook section is Thermal and mechanical processing — cold work percentage.
- Everything except CW is given, so isolate CW symbolically first — never rearrange after the numbers are in.
- Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
- Thermal and mechanical processing of metals uses percent cold work to quantify area reduction during forming.
Step-by-step solution
Step 1 — State the governing relation:
Step 2 — Rearrange symbolically for CW:
Step 3
Step 4 — Substitute the given values:
Step 5 — Evaluate:
CW = 91.4894\ \text{%}Step 6 — Check: returning CW = 91.4894 % to
reproduces the given quantities, and both sides carry the same units.
Why the other options are there
- 183.0 — kept a factor of two that cancels in the correct rearrangement.
- 45.7447 — dropped that same factor in the other direction.
- 100.6 — rounded an intermediate value before the final step.
Reference: FE Handbook — Thermal and Mechanical Processing