Please read :
- Comparison of different casting processes.
- What is casting ? Main application of castings
- Basic Steps of Sand casting
Basic Operation of the casting process
- First we have to make a pattern
- Then the we have to melt the metal by applying heat
- pouring the metal into the mold and confirming that the metal gets the desired shape.
What is Pattern in Casting Process
Why a good Pattern is required in casting ?
- To obtain the desired shape and size.
- It is easy to design and manufacture.
- making a pattern is not expensive.
- It is of high strength.
- Cast Iron / Brass
- Aluminum or White metal
- Plastic gypsum
- Shrinkage allowance (due to cooling)
- Machining allowance (due to machining)
- Shaking allowances (due to rapping)
- Draft allowance (follow the link)
- Distortion allowance (due to irregular shape)
- Split piece pattern
- Match plate pattern
- cope and drag patterns
- sweep patterns
- draw backs
- Loose piece pattern
- Gated pattern
Preparing Mould for the Casting
Different Properties of the moulding sand
- Co-efficient of expansion
- Moisture Content Test
- Fineness Test
- Testing Amount of Clay
- Permeability Test
- Mould hardness test
- Strength or cohesiveness test
Criteria for selecting a furnace for casting
- Capacity needed to hold the molten metal
- Melting rate
- Quality of the melt
- Temperature needed
- Method of pouring
And lastly comes the casting defects. These defects can occur for different reasons like air trapping in the sand mold, low quality sands, improper ramming , defecting sand mold etc. Go through this link for detailed knowledge of casting defects.