Lezione 18: Manufacturing processes

Question 1

List metal processings

Answer 1

Shaping

• Deformation
• Casting
• Powder methods
• Machining

Joining

Surface treatments

Question 2

Talk about hot deformation

Answer 2

Offers a higher shape deformation
No or low hardening (recrystallization)
Oxidized metal surface
Need some surface finishing processes

Question 3

Talk about cold deformation

Answer 3

Needs higher forces and high installation power
Offers a lower shape variation
Higher hardening, so an increase in mechanical strength
Good surface finishing, may not need further finishings

Question 4

What factors impose a size limit for certain processes?

Answer 4

Along with mass, there is a limiting value for section thickness that a given shaping process can handle
-Casting and molding: they rely on material flow in the liquid or semi-liquid state. Lower limits on section thickness are imposed by the physics of flow (no thin sections), also heat loss into the mold increases viscosity, may result in premature solidification. Upper limits are set by problems of shrinkage. Keeping thickness and cross section uniform