3.1.1 Materials and their applications

Question 1

mechanical properties

Answer 1

associated with how a material reacts to an external force

Question 2

compressive strength

Answer 2

the ability to withstand being crushed/shortened by pushing forces (compression)

Question 3

tensile strength

Answer 3

the ability to withstand stretching or pulling forces (tension)

Question 4

shear strength

Answer 4

the ability to resist sliding forces on a parallel plane

Question 5

hardness

Answer 5

the ability to resist abrasive wear such as scratching, surface indentation, or cutting

Question 6

Bending strength

Answer 6

the ability to resist forces that may bend the material

Question 7

Torsional strength

Answer 7

the ability to withstand twisting forces from applied torque or torsion

Question 8

toughness

Answer 8

the ability to absorb impact force without fracture

Question 9

plasticity

Answer 9

the ability to be permanently deformed (shaped) and retain the deformed shape

Question 10

ductility

Answer 10

the ability to be drawn out under tension, reducing the cross-sectional area without cracking, 4eg stretching a material into a wire

Question 11

malleability

Answer 11

the ability to withstand deformation by compression without cracking, it increases with a rise in temperature

Question 12

elasticity

Answer 12

the ability to be deformed and then return to the original shape when the force is removed

Question 13

physical properties

Answer 13

associated with the actual make-up/structure of the material

Question 14

electrical conductor

Answer 14

allows the flow of electrical current through a material, good conductor = gives v little resistance to flow of charge

Question 15

electrical insulator

Answer 15

does not allow the flow of electricity through the material

Question 16

thermal conductor

Answer 16

allows the transfer of heat energy through the material, high thermal conductivity = faster transfer of heat across the material

Question 17

thermal insulator

Answer 17

prevents the transfer of heat through the material

Question 18

thermal expansion

Answer 18

the increase in material volume in response to a heat input

Question 19

opaque

Answer 19

prevents light from travelling through

Question 20

translucent

Answer 20

allows light through but diffuses the light so that objects appear blurred, 4eg frosted glass

Question 21

transparent

Answer 21

allows light to pass through easily which means you can see clearly through the material

Question 22

density

Answer 22

the mass of the material in a standard volume of space

Question 23

fusibility

Answer 23

the ability of the material to be fused or converted from a solid to a liquid or molten state, usually by heat

Question 24

magnetism

Answer 24

the natural force between objects that causes the material to attract iron or steels

Question 25

corrosion/ degradation resistance

Answer 25

the ability of the material to withstand environmental attack and decay

Question 26

ferrous metals

Answer 26

• containing mostly iron and carbon
• magnetic
• will rust
• low/med carbon steel, cast iron

Question 27

non ferrous metals

Answer 27

• X contain iron
• not magnetic
• won’t rust
• aluminium, copper, zinc, silver, gold, titanium, tin

Question 28

alloy

Answer 28

• made of 2+ metals or combining 2 or more elements (one of which must be a metal)
• ferrous alloys- stainless steel, die/tool steel
• non ferrous alloys- bronze, brass, duralumin, pewter

Question 29

hardwood

Answer 29

• broad leafed (deciduous) trees
• slow growing
• lose their leaves in autumn
• oak, mahogany, teak, birch, beech

Question 30

softwood

Answer 30

• cone bearing (coniferous) trees
• fast growing
• evergreen
• pine, spruce, douglas fir, redwood, cedar, larch

Question 31

manufactured board

Answer 31

• a man-made, wood-based composite material

- plywood, chipboard, mdf

Question 32

thermoplastic

Answer 32

• can be repeatedly reheated and reshaped (recyclable)
• have long linear chain molecules held by van der waals forces
• ldpe, hdpe, hips, pp, pet, pvc

Question 33

thermosetting polymer

Answer 33

• when heated, undergoes a chemical change whereby the molecules form rigid cross links
• cannot be reheated and reshaped
• uf, mf, polyester resin, epoxy resin