Materials and their application

Question 1

What are the two principal categories of material properties

Answer 1

Mechanical and physical

Question 2

Mechanical properties

Answer 2

These are how materials react to external forces

Question 3

Physical properties

Answer 3

These are associated with the actual make up/structure of the material

Question 4

Compressive strength (mechanical)

Answer 4

The ability to withstand being crushed or shortened

Question 5

Tensile strength (mechanical)

Answer 5

The ability to resist stretching or pulling forces

Question 6

Bending strength (mechanical)

Answer 6

The ability to resist forces that may bend the material

Question 7

Shear strength (mechanical)

Answer 7

The ability to resist sliding forces on a parallel plane

Question 8

Torsional strength (mechanical)

Answer 8

The ability to withstand twisting forces

Question 9

Hardness (mechanical)

Answer 9

The ability to resist abrasive wear such as scratching or indentation

Question 10

Toughness (mechanical)

Answer 10

The ability to absorb impact force without a fracture

Question 11

Plasticity (mechanical)

Answer 11

The ability to be permanently deformed and retained the deformed shape

Question 12

Ductility (mechanical)

Answer 12

The ability to be drawn out under tension reducing the cross sectional area without cracking it

Question 13

Malleability (mechanical)

Answer 13

The ability to withstand deformation by compression without cracking or breaking. Increases with rise of temperature

Question 14

Ferrous metals

Answer 14

Metal containing iron and carbon, they are magnetic and will rust

Question 15

Examples of ferrous metals

Answer 15

Low carbon steel, medium carbon steel and cast iron

Question 16

Non-ferrous metals

Answer 16

A metal not containing metal and it doesn’t rust and isn’t magnetic

Question 17

Examples of non-ferrous metals

Answer 17

Aluminium, copper, zinc, gold, titanium and tin

Question 18

Examples of alloys

Answer 18

Ferrous alloys: stainless steel, and die steel
Non-ferrous alloys: Bronze, brass duralumin and pewter

Question 18

Hardwoods

Answer 18

A wood from a deciduous tree, which is very slow growing and lose there leaves.

Question 18

Alloy

Answer 18

An alloy is a metal made out of two or more metals or combining two or more metal elements

Question 18

Examples of hardwoods

Answer 18

Oak, ash, mahogany, teak, birch and beech

Question 19

Softwoods

Answer 19

A wood from an coniferous tree which are fast growing and tend to be evergreen

Question 20

Examples of softwoods

Answer 20

Pine, spruce, douglas fir, cedar, redwood and larch

Question 21

Manufactured board

Answer 21

A man-made wood-based composite material

Question 22

Examples of manufactured board

Answer 22

Plywood, chipboard and MDF

Question 23

Thermoplastics

Answer 23

These are materials that can be repeatedly reheated and reshaped allowing it to be recycled.

Question 24

Examples of thermoplastics

Answer 24

LDPE, HDPE, PP, HIPS, PVC and ABS

Question 25

Thermosetting polymers

Answer 25

A material that when heated undergoes a chemical change. They cannot be reheated or reshaped even under high temperatures.

Question 26

Examples of thermosetting polymers

Answer 26

Urea formaldehyde, melamine and epoxy resin.

Question 27

Elastomer

Answer 27

A material that at room temperature can be deformed under pressure and then upon release of pressure will return back to its original shape.

Question 28

Examples of elastomers

Answer 28

Natural rubber, neoprene and silicone

Question 29

Composite

Answer 29

A material composed of two or more different materials giving it enhanced properties.

Question 30

What can composites be

Answer 30

Fibre based, sheet based and particle based

Question 31

Examples of composites

Answer 31

Carbon fibre, glass fibre reinforced plastic, tungsten carbide and composite board

Question 32

Smart material

Answer 32

A material whose physical properties change in response to an input or change in the environment such as light, temperature and pressure

Question 33

Examples of smart materials

Answer 33

Shape memory alloys, photochromic pigment and phosphorescent pigment

Question 34

Modern material

Answer 34

A material developed through the invention of new or improved processes

Question 35

Examples of modern materials

Answer 35

Kevlar, PMC and high density modelling foam

Question 36

Tensile testing

Answer 36

Clamps material samples into a vice and applies weights to the other end and you can see how much it is stretched or pulled

Question 37

Toughness testing

Answer 37

Material is placed inside a clamp and then hit with a hammer to see how much impact it can take. Brittle materials will shatter

Question 38

What are the two types of hardness testing

Answer 38

Abrasive (using sandpaper) and indentation (using a dot punch)

Question 39

Malleability testing

Answer 39

Place material in vice. Try try to bend the piece 90 degrees, cracks on the outside show bad ductility and cracks on the inside shows lack of malleability

Question 40

Corrosion testing

Answer 40

Leave a material outside exposed to the elements and observe the results

Question 41

The two types of conductivity testing

Answer 41

Electrical conductivity (multimeter) and thermal conductivity (thermometer)