Casting, Forming and Welding Multiple Choice Questions on “Classification of Metal Forming Processes”.
1. Which of the following components are manufactured by the sheet metal forming process?
a) Engine blocks
b) Connecting rods
c) Electric wires
d) Car bodies
Answer: d
Clarification: Sheet metal forming is a process which uses ductile materials like aluminium or low carbon steel to form lightweight products with versatile features. Car bodies are mainly manufactured by sheet metal forming by performing operations like shearing, slitting, cutting, or sawing of thin metal plates. This method is also used for making parts like beverage cans, metal desks, appliances etc.
2. Which of the following processes is not the type of metal forming process?
a) Extrusion
b) Injection moulding
c) Forging
d) Drawing
Answer: b
Clarification: Extrusion, forging and drawing process are the main general types of metal forming process, while the injection moulding is other process which is basically a part of casting process which includes the formation of parts by injecting the melt into a cavity by the help of a plunger. This method is not the part of metal forming because the phase change of metal occurs during the process.
3. Cold forming is a process which works when the temperature of metal is above its re-crystallization temperature.
a) True
b) False
Answer: b
Clarification: On the basis of temperature, metal forming mainly has two types which are cold forming and hot forming. Hot forming is defined as the mechanical working of metal at higher temperature above its re-crystallization temperature. And cold forming is a process which works at temperature below the re-crystallization temperature of metal.
4. Which of the following manufacturing processes operates under the influence of external forces?
a) Metal forming
b) Powder metallurgy
c) Casting
d) Welding
Answer: a
Clarification: In the metal forming process, the raw material is converted into a desired shape by the application of external force. The metal work piece is subjected to plastic deformation which results in changing of shape and size of the work piece or specimen under the influence of external forces or stresses.
5. Which of the following stresses is takes place during performing the wire drawing operation?
a) Tensile stress
b) Bending stress
c) Indirect compressive stress
d) Shear stress
Answer: c
Clarification: Wire drawing is a forming process in which a round metallic bar is pulled by a machine by generating indirect compressive stresses in the bar. This causes thinning of bar and results in the formation of thin wires that further used as a cable or for electricity purposes. Wire drawing is most suitable for ductile materials.
6. Wire drawing process is almost similar to deep drawing process.
a) True
b) False
Answer: b
Clarification: Wire drawing process is quite different from deep drawing process. In wire drawing, metallic bar is pulled to form wires, while in deep drawing process; a flat metal sheet is converted into a concave shape part. This operation is basically performed by stretching the metal for which a blank-holder is used to clamp the blank on the die, and then a punch is used which pushes the metal sheet.
7. Closed die forging process is also called as impression die forging.
a) True
b) False
Answer: a
Clarification: Closed die forging is also called as impression die forging. In this method, die consists of some internal impression that imparted to the work piece or specimen used for the forming. During full closing of die, impression is fully filled with the deformed billet and then further taken out of the impression to form flash.
8. For the minimum metal loss, the flash-less forging is better than the impression die forging.
a) True
b) False
Answer: a
Clarification: In flash-less forging, the material is fully restricted within the die, so no any flash is produced during the process, which completely optimizes the material used. But in impression die forging, flash can be produced which is considered as scrap material that is removed from the formed part. So, the flash-less forging is better than the impression die forging for the minimum metal loss.
9. Formability is a mechanical property which defined as the ability of solid metal to get converted into the liquid phase.
a) True
b) False
Answer: b
Clarification: In the metal forming processes, formability is an essential mechanical property which is defined as the ability of sheet metal or any material to undergo shape change without occurring of any failures like tearing or necking in the metal part. This property is vital and must be present in the material to be used for the metal forming process.
10. Shearing is a cutting operation in which material or work piece is subjected to shear stresses.
a) True
b) False
Answer: a
Clarification: In the shearing process, a proper sized piece of sheet metal is removed from a larger sheet by cutting operation in which the work piece is subjected to shear stresses. Shearing normally starts with small cracks which further grow and failure takes place. This method generates rough surfaces due to rough cutting.