Flashcards in Manufacturing Processes Deck (27):
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.
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.
What are the following disadvantages of Gravity Die Casting?
High initial cost.
A large production volume is needed to make this an economical option.
Another name for Investment Casting is?
Lost Wax Casting
What are the following advantages of Investment Casting?
Can produce complex shapes.
Smooth surface finish.
Minor secondary machining.
Dimensional accuracy is good.
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.
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.
Less labour needed
Less material used.
Reasonable degree of accuracy.
Forged parts can be easily welded.
What are the following disadvantages of Forging?
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.
What are the following advantages of Injection Moulding?
Low scrap weight.
Good for complex parts.
Good control of part size and shape.
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.
What is the required temperature of hot rolling?
What is the required temperature of warm rolling?
What is the required temperature of cold rolling?
Room temperature (23°C)
The rolls in between the stands of a finishing mill are called?
Looper rolls or tension rolls
The steel going through a finishing mill is called?
The rolls in the middle of a finishing mill are called?
The large rolls in the finishing mill are called?
Back up rolls
What is the name of the part of a finishing mill which contains the rolls?
Stands or mill housing
Iron Ore is imported from?
Coal is imported from?
Limestone is imported from?
Olivine Sand is imported from?
What are the six steps of injection moulding?
What is the process of the grains in a material when it undergoes in a hot rolling mill?
What are the four main metallic casting processes?
Gravity Die Casting
Pressure Die Casting
Name two types of a reheat furnace?
Walking beam (PT)
Pusher design (LL)