Page 167 - Module DMV20173

EXERCISE 4.5

Many axisymmetric missile bodies are made by spinning. What other methods could
you use if spinning processes were not available?

Solution:
Missile components which are spun usually have large cross-sections. Some of
these parts could be made by explosive forming or welding of a number of smaller
rolled and stamped pieces. Smaller components could possibly be forged or formed

by stretch forming.

EXERCISE 5.1

Namely four typical defects in flat rolling.

Solution:
i) Wavy edges.
ii) Zipper cracks.

iii) Edge cracks.
iv) Alligatoring.

EXERCISE 5.2

In impression-die forging, during deformation, some of the material flows outward
and forms a flash. Explain the functions of flash in impression-die forging.

Solution:

Functions of flash in impression die forging:
1. High pressure and high frictional resistance in the flash, present a severe
constraint to the material in the die for outward flow.

2. Based on the plastic deformation principle, material flow in direction of
least resistance.
3. Therefore the material begins to flow into the die cavity and filling it
completely.