1. Metal Processes

2. CASTING

3. Shrinkage
The cavity is usually made oversize to allow for the metal contraction as it cools down to room temperature. This is achieved by making the pattern oversize. To account for shrinking, the pattern must be made oversize by these factors, on the average.
Metal
Pattern Oversize Factor (each direction)
Finish Allowance (smaller number for larger sizes)
Min Wall mm (inches)
Aluminium
0.5 to 1.0 %
4.75 (0.18)
Copper alloys
2.3 (0.094)
Grey Cast Iron
1.10
0.4 to 1.6 %
3.0 (0.125)
Nickel alloys
1.05
N/A
Steel
0.5 to 2 %
5 (0.20)
Magnesium alloys
4.0 (0.157)
Malleable Irons
0.6 to 1.6 %

4. First steps
The pattern is place in the drag with its parting line down.
The pattern is then dusted with parting dust. Parting dust is a powder that will not absorb moisture. This provides a barrier between the pattern and the moulding sand. The parting dust makes it easier to remove the pattern later in the process.

5. Filling with sand
Ramming the sand

6. The finished article Pouring the metal

7. Useful websites www.wynndanzur.com www.dansworkshop.com www.almmc.com

8. Defects Metallic projections Cavities Discontinuities
There are seven basic types of defects that occur in casting:
Metallic projections
Cavities
Discontinuities
Defective surface
Incomplete casting
Incorrect dimensions/shape
Inclusions
Using the computers find the definitions for these terms

9. Modifying characteristics using heat
Using the following terms below find out the definition and explain the advantages and disadvantages of each.
Annealing
Case hardening
precipitation strengthening
Tempering
quenching

10. Metal processes
Using the following terms below find out the definition and explain the advantages and disadvantages of each. And a supporting image for the process.
Milling
Turning
Pressing
Stamping