Materials and their properties

Question 1

What needs to be known to specify a metal

Answer 1

Chemical composition 
Surface Treatment
Production and finishing method 
Supply form (sheet, tube..)
Quality Control standards

Question 2

What carbon content is Wrought iron

Answer 2

Up to 0.008%

Question 3

What carbon content is cast iron

Answer 3

Above 2%

Question 4

What type of iron is used for general engineering applications and what is its carbon content

Answer 4

Very low carbon

up to 0.05%

Question 5

What must stainless steel contain

Answer 5

10.5% chromium, silicon or manganese

Question 6

What are the 3 steel groups

Answer 6

Austenitic
Martensitic
Ferritic

Question 7

What is brass defined ass

Answer 7

An alloy of copper and another element

Question 8

What are some good general properties of copper based metal

Answer 8

Good electrical and thermal conductors
Weak
Easy to work
Good wear characteristics

Question 9

What are some properties of magnesium

Answer 9

Light
Very low tensile strength
Very easy to mould

Question 10

What are sources of plant based polymers

Answer 10

Cellulose
Tree resins
Starches

Question 11

How do polymer branches effect the performance of a polymer

Answer 11

Side branches create entanglements to prevent deformations
Reduces stress cracking
Reduces density

Question 12

Are thermosets or thermoplastics Cross linked

Answer 12

Thermosets

Question 13

How does cross links effect a polymer

Answer 13

Makes the polymer harder, stronger, stiffer, more brittle and more dimensionally stable

Question 14

What is a homopolymer

Answer 14

All the mers are the same type

Question 15

What is a co polymer

Answer 15

2 different types of mer are used

Question 16

What is a Terpolymer

Answer 16

Contains 3 different mer units

Question 17

Are branched or linear polymers more crystalline

Answer 17

Linear

Question 18

How does crystallinity Effect material properties

Answer 18

Stiffer, harder, denser, more resistant to heat and solvents.
Reduces ductility or transparency

Question 19

What material properties are effected by molecular weight

Answer 19

Tensile strength
Impact strength
Resistance to cracking
Viscosity when molten

Question 20

What is the degree of polymerisation

Answer 20

Ratio between molecular weight of polymer and molecular weight of repeating unit

Question 21

Polymers with a high degree of polymer have a higher……

Answer 21

Viscosity

Question 22

What are the differences between thermosetting plastics and thermoplastics

Answer 22

Thermosets have stronger bonds and will not melt they will just burn eventually, during heating the hardness and strength is unchanged
Thermoplastics have weaker bonds and will undergo melt or glass transition upon heating

Question 23

What materials are often used as additives to plastics

Answer 23

plasticisers 
Carbon black
Antioxidants
Fillers
Colourants
Flame retardants
Lubricants

Question 24

What is material is most commonly added to reinforce polymers

Answer 24

Glass fibres

Question 25

What properties of materials can be enhanced through reinforcing polymers

Answer 25

Improved strength, stiffness, dimensional and thermal stability but can be more difficult to mould

Question 26

What does REACH stand for

Answer 26

Registration Evaluation, Authorisation and restriction of chemicals

Question 27

What are some materials banned by reach

Answer 27

Cadmium, lead