Metal Processes

Question 1

What is Casting?

Answer 1

Pouring molten metal into a mold and allowing it to solidify by letting it cool. The mold can be made from various materials such as sand, metal or ceramic. There are 2 main types of casting; Permanent mold casting where metal is poured into a permanent metal mould and Sand casting where metal is poured into a sand mold.

Question 2

Advantages of Casting

Answer 2

• Can create complex shapes
• Low labour costs

Question 3

Disadvantages of Casting

Answer 3

• Surface finish is often poor
• Limited to low volume production

Question 4

What is Forging?

Answer 4

Forging is a manufacturing process involving the shaping of metal using localised compressive forces. The metal used is mostly wrought iron.

Question 5

Advantages of Forging

Answer 5

• Excellent surface finish
• Good dimensional accuracy
• Can create very strong parts

Question 6

Disadvantages of Forging

Answer 6

• High labour costs
• Limited to low volume production

Question 7

What is Drop Forging?

Answer 7

Similar to normal forging except instead of a hammer there is a ram which exerts more force and faster than a human could with a hammer. Sometimes molds and formers can be used to smash the metal into. Spanners, pliers and screwdrivers are made using drop forging.

Question 8

Advantages of Drop Forging

Answer 8

• Faster than regular forging
• Less time consuming
• Molds and formers can be used

Question 9

Disadvantages of Drop Forging

Answer 9

• Quite expensive
• Very loud

Question 10

What is Bending?

Answer 10

Metal is clamped into place and the punch is lowered into the metal with increasing pressure so it takes the shape of the die (most commonly 90 degree bends). One off and large scale batch production.

Question 11

Advantages of Bending

Answer 11

• Can create a variety of shapes
• High production rates
• Low labour costs
• Can produce long lengths of metals

Question 12

Disadvantages of Bending

Answer 12

• Limited to small parts
• Surface finish is often poor
• Can cause cracking or warping if the metal is not properly supported
• Tooling and dies is expensive

Question 13

What is Press Forming?

Answer 13

Press forming is used to shape sheet material into 3D forms/ shapes. Used for car body panels, boxes and containers. Metals commonly used include: medium carbon steel, aluminium.

Question 14

Advantages of Press Forming

Answer 14

• High Production rates
• Low labour costs
• Can create complex geometries

Question 15

Disadvantages of Press Forming

Answer 15

• Limited by the thickness of the material
• Parts produced may have sharp edges
• Difficult to form very thick or very thin metal