YOUR AIMS

On completion of this lesson you should be able to:

- describe casting methods
- describe methods used to produce rolled and drawn sections
- describe the extrusion process
- describe the forging process
- give examples of products produced by casting, rolling, forging and extrusion.

1. Rate the four main casting processes, in descending order, for
(a) surface quality
(b) operating cost.

2. In investment casting, why are wax moulds produced from dies made from different materials?

3. What are the advantages of low pressure die casting compared with gravity die casting?

4. Briefly compare the process of drop forging with press or smith forging.

5. How does cold working affect the properties of a metal?

6. Give two metal products which may be produced by:
(a) casting
(b) rolling
(c) forging
(d) extrusion.