classification of engineering materials (T1)

Question 1

what are the four classifications

Answer 1

elements, solutions, compounds, mixtures

Question 2

elements

Answer 2

• basic building blocks of matter
• elements cannot be broken down into simpler material
• most material do not exist naturally as pure elements

Question 3

solutions

Answer 3

• solution is where a substance dissolves in another
• eg sugar in tea or salt in water
• metals may also dissolve in other metals to form solutions
• eg carbon in iron to form steel
• solutions can exist as liquid or solids

Question 4

compounds

Answer 4

• 2 or more elements chemically combined
• can be broken into two elements that make then up
• eg salt — sodium and chloride

Question 5

mixtures

Answer 5

two or more elements OR compounds mixed together mechanically with regard to any fixed proportion
- can be separated eg air, cement, alloy mixtures

Question 6

metals

Answer 6

composed of one or more metallic elements and often also non metallic elements in relatively small amounts
- term metal alloy refers to metallic substance that is composed of two or more elements

Question 7

ceramics

Answer 7

compounds between metallic and non metallic elements; frequently oxides, nitrides and carbides
- naturally occur as clay and rock
- any ceramic material needs some form of purification, mixing or firing is a synthetic ceramic

Question 8

polymers

Answer 8

plastic and rubber material
- organic compounds that are chemically based on carbon, hydrogen and other non metallic elements

Question 9

material classification: how we group materials together (4)

Answer 9

• properties
• ways prepared
• atomic/crystal structure
• way used in industry

Question 10

biological materials

Answer 10

materials that are result of life cycle of plant or animal
naturally occuring:
- wood, wax, leather, limestone
manufactured:
- paper, composite wood products, lime and diatomic bricks

Question 11

composite materials

Answer 11

materials made of different combined materials
- fibreglass
- carbon fibre reinforced polymer
- concrete with steel reinforcing