This set of Mechanical Metallurgy Multiple Choice Questions & Answers (MCQs) focuses on “Classification of Forging Process”.
1. The fullering process is related to which of the following metal working process?
Explanation: The fullering process is related to forging where the cross-sectional area of the sample is reduced. It is also carried out to draw the material for further processing such as the rolling.
2. The connecting rod of crack shift is made of which of the following process?
Explanation: The connecting rod is made by forging the bar stock directly into the desired shape by forging. This provides high strength to the rod and avoids defects associated with the casting process.
3. The flash is generally obtained in which category of forging process?
a) Open die forging
b) Closed die forging
c) Hydraulic pressing
d) Impact forging
Explanation: The flash is extra extruded material that is squeezed out after the final shape of the product is obtained inside the die.
4. In casting, the mold is manufactured with tampered and draft allowance, whereas in closed die forging, the draft allowances are not required.
Explanation: The draft and taper allowance is necessary even in closed die forging. It is useful in filling the cavity properly, and easy removal of the sample after the forging is completed.
5. The main cause for hot tear in the forging is due to presence of ____________
Explanation: The hot tear occurs during solidification of hot forged workpiece; the inclusion is a region of high-stress concentration and causes the crack initiation due to stress concentration.
6. Which is the most significant property to determine the enforceability of material?
a) Fracture toughness
d) Fatigue strength
Explanation: The malleability is the property of a material to draw in complex shapes without breaking. So, if a material has higher malleability, it will have higher formability. The ductility is significantly related to malleability.
7. In case of open die forging, the relative movement of a workpiece with die is lower in lubricated sample than the unlubricated one.
Explanation: The lubricated sample is free to move on the surface of material because of less friction present to resist the movement; hence, the relative movement of the lubricated sample is higher than unlubricated.
8. The lubricated sample shows more barrelling compared to the unlubricated sample which shows less barrelling.
Explanation: The reverse of this statement is true, this is because the lubricated sample is free to move off the surface of die, so compression of sample is more uniform, and chances of barrelling are lowered.
9. If narrower the flash width _________ will be the pressure in the die as well as vice versa.
c) no relationship will pressure
d) the length of the flash decides the pressure, not the width
Explanation: If narrower the flash width, there will be less space available for the escaping of extra material from the die, hence the pressure will build inside the chamber, and tiny intricate shape will also get filled.
10. In the forging operation, the sticking friction condition occurs at which location?
a) At entrance
b) In the center
c) At the exit
d) Can occur anywhere
Explanation: In forging operation, the sticking friction condition generally happens in the center of the workpiece, this is because the material flow is restricted to the nearby region.
11. The following figure shows a cylindrical sample under compression, and there is a friction between the workpiece and the machine. The no deformed area is indicated correctly in the below figure.
Explanation: The region touching the dies will have the high friction, so it will not deform easily and stick to the surface of the die. Hence remains unreformed, while the central outer region will deform most.
12. The cylindrical sample of the same diameter but different height is compressed. The stress required in sample with __________ height will require ________ stress than the sample with __________ height.
a) more, more, less
b) more, less, less
c) less, less, more
d) less, more, more
Explanation: If two samples are of same diameter than the sample with lower height will require more stress to deform than the sample with more height. This is because the larger undeformed region is in the smaller sample.
Sanfoundry Global Education & Learning Series – Mechanical Metallurgy.
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