Materials

Question 1

What are two hardwoods?

Answer 1

Oak and ash.

Question 2

Properties of oak:

Answer 2

1. Has an attractive light colour.
2. Is heavy, dense, contributing to its strength.
3. Good weather resistance.
4. But it is a very high-cost hardwood.

High-quality indoor and outdoor furniture.

Question 3

Properties of ash:

Answer 3

1. Has a more pale and light colour.
2. Open grain, making it flexible.
3. Very hard, dense and quite tough.
4. A lower-cost hardwood.

Used for equipment handles such as for sports equipment or workshop tools.

Question 4

What are two softwoods?

Answer 4

Pine and redwood.

Question 5

Properties of pine:

Answer 5

1. Light colour.
2. Is lightweight.
3. Good strength.
4. Can be quite knotty.
5. Very affordable.

Used for exterior frame construction, indoor or outdoor flooring and furniture.

Question 6

Properties of redwood:

Answer 6

1. Has a rich, brown-reddish colour.
2. Lightweight.
3. Quite durable.
4. Good weather resistance.
5. Low-cost.

Outdoor and indoor furniture like decking, fences, gates.

Question 7

What are three ferrous metals?

Answer 7

Low carbon/mild steel, stainless steel and high speed steel.

Question 8

Properties of low carbon steel:

Answer 8

1. Good tensile strength.
2. Is quite heavy.
3. Is malleable and ductile.
4. Has poor rust resistance.
5. Relatively low-cost.

Used for mechanical fixings and many car parts.

Question 9

Properties of stainless steel:

Answer 9

1. Has an attractive, shiny, silvery appearance.
2. Has high corrosion resistance.
3. Has high tensile strength.
4. Is malleable and ductile.
5. Is more expensive than mild steel.

Used for cookware and kitchenware.

Question 10

Properties of HSS:

Answer 10

1. High heat and wear resistance.
2. Is extremely hard.
3. It is high-cost.

Used for cutting tools such as drill bits and saw blades.

Question 11

What are two non-ferrous metals?

Answer 11

Aluminium and copper.

Question 12

Properties of aluminium:

Answer 12

1. Is a lightweight metal.
2. Malleable and ductile.
3. Has rust resistance.
4. Is a good electrical and heat conductor.
5. Is relatively low-cost.

Used for exterior framing for vehicles and for packaging.

Question 13

Properties of copper:

Answer 13

1. Has a unique, reddish appearance.
2. Highly ductile and easily shapable.
3. Has rust resistance.
4. Good electrical and heat conductivity.
5. Medium-cost.

Used for piping and electronic wires, circuit boards.

Question 14

What are four thermoplastics?

Answer 14

Acrylic, nylon, PVC and ABS.

Question 15

Properties of acrylic:

Answer 15

1. Lightweight.
2. Easy to cut and shape.
3. Good impact resistance.
4. Is flexible.

Used for food packaging, toys and miscellaneous products.

Question 16

Properties of nylon:

Answer 16

1. Has high tensile strength.
2. Better temperature resistance.
3. Good elasticity.
4. Low friction.

Used in gears, curtain rails, seat belts, ropes, fishnets.

Question 17

Properties of PVC:

Answer 17

1. Very strong.
2. Is lightweight.
3. High impact strength.
4. High chemical resistance.

Piping and cable insulation.

Question 18

Properties of ABS:

Answer 18

1. Is very durable and hard.
2. High impact resistance.
3. Lightweight.

Keycaps and printers.

Question 19

Properties of epoxy resin:

Answer 19

1. Excellent adhesive properties.
2. Very hard, durable and strong.
3. High heat, electrical and chemical resistance.

Coating by electrical components or as an adhesive for joining wood or metal.

Question 20

What are two thermosetting plastics:

Answer 20

Urea formalyde and epoxy resin.

Question 21

Properties of rubber:

Answer 21

1. Highly elastic.
2. Good wear resistance.
3. Good shock absorption.
4. Remains flexible at low temperatures.

Cat tyres, balloons, electrical cable insulation.

Question 22

Properties of silicon:

Answer 22

1. High flexibility and elasticity, even at low temperatures.
2. Has a high melting point.
3. Low friction, lubricating properties.

Flexible trays, electronics (silicon chips), toys.

Question 23

What adhesives are used for wood?

Answer 23

1.PVA - water based, setting time = 30min - 1hr.

2. Epoxy resin - toxic, setting time = 30min - 2hr.

Question 24

What adhesives are used for plastic?

Answer 24

1. Cyanoacrylate (super glue) - lightweight applications, toxic, setting time = instantly.
2. Epoxy resin - toxic, setting time = 30min - 2hr.

Question 25

What adhesives are used for metal?

Answer 25

1. Cyanoacrylate (super glue) - lightweight applications, toxic, setting time = instantly. 2. Epoxy resin - toxic, setting time = 30min - 2hr.

Question 26

What are three manufactured boards?

Answer 26

MDF, plywood, chipboard.

Question 27

What plastics are used for vacuum forming?

Answer 27

Only thermoplastics - acrylic, PVC, ABS.

Question 28

What plastic are used for injection moulding?

Answer 28

Only thermoplastics - polypropylene, polyethylene, nylon.

Question 29

What metals are used for brazing/hard-soldering?

Answer 29

1. Steel, aluminium, copper. 2. The filler metal can be a dissimilar metal to the one being used together.

Question 30

What metals are used for gas-welding?

Answer 30

1. Steel, aluminium, copper. 2. The filler metal can be a dissimilar metal to the one being used together.

Question 31

What are ferrous and non-ferrous metals?

Answer 31

1. Ferrous - metals containing mostly iron and carbon, they are magnetic and will rust. 2. Non-ferrous - a metal that does not contain iron, non-ferrous metals are not magnetic and do not rust.

Question 32

What are smart materials?

Answer 32

A smart materials is a material whose physical properties change in response to an input or change in the environment, such as electricity, pressure, temperature or light.

Question 33

What are hardwoods and softwoods?

Answer 33

1. Hardwood - a wood from deciduous/broad-leafed trees, these trees are generally slow growing and lose their leaves in autumn. 2. Softwood - a wood from coniferous/cone bearing trees, these trees are generally fast growing and tend to be evergreen.

Question 34

What are thermopolymers and thermosetting polymers?

Answer 34

1. Thermoplastic - a material which can be repeatedly reheated and reshaped, allowing it to be recycled after its initial use. 2. Thermosetting polymer - a material which when heated undergoes a chemical change, meaning it cannot be reheated and reshaped, even at very high temperatures.

Question 35

What are alloys?

Answer 35

An alloy is a metal made of two or more metals, or combining two or more elements, one of which must be metal, alloys can be ferrous or non-ferrous too.

Question 36

What are elastomers?

Answer 36

An elastomer is a material which at room temperature can be deformed under pressure and then upon release of the pressure, will return to its original shape.

Question 37

What are composite materials?

Answer 37

A composite material is a material comprised of two or more different materials, resulting in a material with enhanced properties.

Question 38

Properties of MDF:

Answer 38

1. No knots, has a very smooth surface 2. Very hard, high-density 3. Quite strong, stable 4. Typically quite heavy 5. Very low cost

Question 39

Properties of plywood:

Answer 39

1. Very strong and stable in all directions 2. Lightweight 3. High flexibility 4. Quite low cost