Manufacturing Processes Flashcards Preview

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Flashcards in Manufacturing Processes Deck (27):
1

10 Rules for good castings?

1. Start with a good quality melt.

2. Don’t make the meniscus go too fast - max 0.5 m/s.

3. Don’t stop the meniscus.

4. Avoid bubbles.

5. Avoid core blows.

6. Avoid shrinkage.

7. Avoid convection.

8. Reduce segregation.

9. Reduce residual stress.

10. Provide location points.

2

What are the following advantages of Gravity Die Casting?

Good dimensional accuracy.

Smooth cast surfaces.

Thinner walls can be cast.

Reduces or eliminates secondary machining.

Rapid reduction rates.

Casting tensile strength is higher.

3

What are the following disadvantages of Gravity Die Casting?

High initial cost.

A large production volume is needed to make this an economical option.

4

Another name for Investment Casting is?

Lost Wax Casting

5

What are the following advantages of Investment Casting?

Can produce complex shapes.

Smooth surface finish.

Minor secondary machining.

Dimensional accuracy is good.

6

What are the following disadvantages of Investment Casting?

Process is expensive for one offs.

Usually limited to small casting.

Holes cannot be smaller than 1.6 mm and should be no deeper than 1.5 times the diameter.

Long production-cycle times.

Cant be used for high-volume manufacturing.

7

What are the following advantages of Forging?

Forged parts possess high ductility.

Great resistance to impact and fatigue loads.

Refines the structure of the metal.

Time efficient

Less labour needed

Less material used.

Good reliability.

Reasonable degree of accuracy.

Forged parts can be easily welded.

8

What are the following disadvantages of Forging?

Rapid oxidation.

Close tolerances are difficult to maintain.

Limited to simple shapes.

Some materials can not be forged.

Initial cost of forging dies are high

High maintenance cost.

Metals gets cracked or distorted.

9

What are the following advantages of Injection Moulding?

Low scrap weight.

Good for complex parts.

Cost effective.

Good control of part size and shape.

High consistency.

10

What are the following disadvantages of Injection Moulding?

Too expensive for one-offs.

Long lead time.

High tooling cost.

Requires uniform wall thickness.

Complicated computer modelling.

11

What is the required temperature of hot rolling?

Above 900°C

12

What is the required temperature of warm rolling?

Above 720°C

13

What is the required temperature of cold rolling?

Room temperature (23°C)

14

The rolls in between the stands of a finishing mill are called?

Looper rolls or tension rolls

15

The steel going through a finishing mill is called?

The strip

16

The rolls in the middle of a finishing mill are called?

Work rolls

17

The large rolls in the finishing mill are called?

Back up rolls

18

What is the name of the part of a finishing mill which contains the rolls?

Stands or mill housing

19

Iron Ore is imported from?

Australia

Canada

Brazil

South Africa

20

Coal is imported from?

USA

Australia

Canada

21

Limestone is imported from?

South Glamorgan
Cumbria

22

Olivine Sand is imported from?

Norway

23

What are the six steps of injection moulding?

Mould closing

Injection

Holding

Cooling

Mould opening

Ejection

24

What is the process of the grains in a material when it undergoes in a hot rolling mill?

Coarse
Plastic deformation
Recrystallisation
Fine

25

What are the four main metallic casting processes?

Sand Casting
Gravity Die Casting
Pressure Die Casting
Investment Casting

26

Name two types of a reheat furnace?

Walking beam (PT)
Or
Pusher design (LL)

27

What are the following advantages of a coil box?

Reduced length of delay table.

Peak power requirement reduced by 13%.

Energy saving by 6%.

Drive power in finishing train reduced to 40%.