Question

A)Please give brief answers to rolling process questions below;

1) Which parameters affect possible maximum draft in rolling operations? Please also explain that process and product effects if these parameters increased and decreased.

2) Please explain effect of material speed during rolling process.

3) Please explain what kind of effects could be seen on process and product if rolling force increased and decreased more than its optimum value?

B)Please give brief answers to extrusion process questions below;

1) What kind of products can be manufactured by using extrusion process? Give product examples which are composed of metal and plastic.( 6 metal, 3 plastic)

2) Please indicate extrusion die angle on a basic hand drawing sketch, and explain what happen if the die angle increased and decreased.

3) What is impact extrusion?

C) Please give brief answers to deep drawing process questions below;

1) What is LDR for deep drawing process? Explain its effect on process and product if it is increases and decreases.

2) What are the most common observed defect types during deep drawing process? Please also illustrate them with a simple hand sketch.

3) Which parameters affects drawing force? Please comment on them.

D)Please give brief answers to shearing process questions below;

1) What is punch and die mission during shearing process? Explain why punch and die clearance is important?

2) Please explain the shearing process types. At least give 3 types with 2 product examples.

E)Please explain the processes asked below;

1) What is Mannesmann process? Please explain Mannesmann effect. Give at least 3 product examples

2) What is rotary swaging process? Give at least 3 product examples.

I REALLY NEED YOUR HELP IN THIS HOMEWORK. PLEASE:) THNAK YOU SO MUCH!!

Answer 1

Answer A 1:

The maximum possible draft is defined as in equation below; it can be shown that this quantity is a function of the roll radius, R and the coefficient of friction,, between the strip and the roll by the following relationship:

thus the radius of the roll and the coeficient of friction are the parameters which affect the maximum possible draft in rolling operations.

As expected, the higher the friction and the larger the roll radius, the greater the maximum possible draft becomes. Note that this situation is similar to the use of large tires (high R) and rough treds (high ) on form factors and off-road earthmoving equipments, thus permitting the vehicles to travel over rough terrain without skidding.

Answer A 2:

Material speed controls the properties such as Flow stress, strain rate roll force, heat of deformation and interface heat traansfer coefficient during Rolling process. As we know that rolling speed is decreases when rolling diameter is increasing, then

a) Effective Stress: Effective stress is decreasing with increasing diameter or with decreasing material speed.

b)Effective strain: Effective strain is also decreases with increasing diameter or decreasing material speed.

c)Shear Stress: Shear stress effects on deformation and it also decreases with decreasing material speed.

d)Hardness: As the speed has effect on rolling force the decrease in speed reduces the rolling force and meanwhile the stresses.

Answer A 3:

Rolling Force: The rolls apply pressure on the flat strip in order to reduce its thickness, resulting in a roll force, F. Note that this force appears as perpendicular to the plane of the strip, rather than at an angle. This is because, in practice, the arc of contact is very small compared with the roll radius, so we can assume that the roll force is perpendicular to the strip without causing significant error in calculations.

The roll force in flat rolling can be estimated from the formula,

(For a frictionless situation:however, an estimate of the actual roll force, including friction, may be made by increasing this calculated force by about 20%). Where average flow stress and the product is the roll-work contact area.

Case1: Force approximation: low friction

Case2: Force approximation: high friction

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