Metal Processes

Describe the Sand Casting process (For molten metal)

Molten metal is poured into a sand mould. It is cheap and good for very large parts, but has a rough surface finish and low accuracy.

Describe the Investment Casting process and what is it used for?

A wax model is coated in ceramic, the wax is melted out, and metal is poured in. Excellent for complex jewelry or engine parts with high detail.

Desribe the Die Casting process

Similar to plastic injection moulding.

It is for high volume, high precision parts like engine blocks or laptop shells.

What are the 3 main ways to perform sheet metal forming and explain them.

Involves bending, cutting, and "deep drawing".

Cutting - Can use waterjet cutting or laser cutting to create patterns

Bending - A press brake is used to perform single axis bending on a sheet of metal. It contains two parts, a punch and a die.

Deep Drawing - A sheet metal blank is drawn into a forming die by the mechanical action of a punch or a series of punches.

What is metal forging?

Metal is beaten or pressed into shape. This aligns the "grain" of the metal, making it incredibly strong (e.g., hand tools, turbine blades).

What is metal extrusion and what is it used for?

A heated metal billet (usually aluminum) is pushed through a shaped die (like squeezing toothpaste).

It creates long profiles with a constant cross-section (e.g., window frames, heat sinks, bike rims).