The Technological world (Materials, Constraints and deformations)

Question 1

What are the mechanical properties (5)

Answer 1

• Hardness
• Resilience
• Malleability
• Ductility
• Stiffness
• Corrosion resistance

Question 2

What is hardness ?

Answer 2

Resist deformation when hit.

Question 3

What is resilience ?

Answer 3

Resist shock and impact with deforming

Question 4

What is malleability ?

Answer 4

Can be compressed without breaking.

or flattened or bent without breaking

Question 5

What is ductility ?

Answer 5

Can be stretched without breaking

Question 6

What is stiffness ?

Answer 6

Can maintain shape when put through many constraints

Question 7

What is corrosion resistance ?

Answer 7

Can resist smoke, salt and chemical properties.

Question 8

What are the types of constraints ? (5)

Answer 8

• Compression
• Tension
• Torsion
• Deflection
• Shearing

Question 9

What is compression ?

Answer 9

Crushing the material

Question 10

What is tension ?

Answer 10

Stretching the material

Question 11

What is Torsion ?

Answer 11

Twist the material

Question 12

What is Deflection ?

Answer 12

Bend the material

Question 13

What is Shearing ?

Answer 13

Cutting the object

Question 14

What are the types of deformations ? (3)

Answer 14

• Elastic
• Plastic
• Fracture

Question 15

What is the plastic deformation ?

Answer 15

Permanent change in shape of object

Question 16

What is the elastic deformation ?

Answer 16

Constraints that leads to temporarily change in shape, when constraint is removed the shape returns to its original shape

Question 17

What are some properties of plastic ?

Answer 17

-Durable
-Cheap (General)
-Light
-Sometimes transparent
others

Question 18

What are plastic made from ?

Answer 18

Fossil fuels

Question 19

What are fossil fuels made from ? (2)

Answer 19

• Oil

- Gas

Question 20

What is positive about plastic degradation ?

Answer 20

The process is slow, but irreversible

Question 21

What are signs of degradation ? (2)

Answer 21

• Cracking

- Change in color

Question 22

What are the types of plastic ? (2)

Answer 22

• Thermoplastics

- Thermosetting

Question 23

What are Thermoplastics ?

Answer 23

Plastic that becomes soft when heated so it can be molded or remolded and then hardens. Usually can recycled

Question 24

What are Thermosetting plastics ?

Answer 24

Plastic that remains permanently hard even when heated. once they are hardened the shape cannot be changed. Cant be recycleed

Question 25

How are Thermosetting plastics made ?

Answer 25

They are made by adding monomers to a mold, and

Question 26

How can you protect against penetration of liquid ?

Answer 26

By adding water proof coating

Question 27

How can you protect against oxidation ?

Answer 27

By adding anti oxidants

Question 28

How can you protect against ultraviolet rays ?

Answer 28

By adding dark pigments to absorb UV rays

Question 29

How are ceramics formed ? Explain the process

Answer 29

When inorganic compounds are heated, the water evaporates and the bonds between the compounds are rearranged to form ceramics

Question 30

How is low electrical conductivity used ?

Answer 30

They are used as insulators

Question 31

How is hardness used ?

Answer 31

Used in building material

Question 32

How is heat resistance and low thermal conductivity used ?

Answer 32

Kitchen appliances

Question 33

How is resistance to corrosion used ?

Answer 33

Used in ducts for fumes and | water coolant in your car

Question 34

How is resilient used ?

Answer 34

Used in engines.

Question 35

What are composites ?

Answer 35

Many materials combines to get a mix of properties ?

Question 36

What are matrix composites like ?

Answer 36

They are like skeletons

Question 37

What are reinforcement composites like ?

Answer 37

They are like muscles and fat

Question 38

What is fibreglass ? what are its properties ?

Answer 38

Made of glass (ceramics) in form of fibers - Stiffness - Corrosion resistance

Question 39

What is aramid fibers reinforcement ? what are its properties ?

Answer 39

Known as kelvar - Low density - Resilience

Question 40

What are carbon fibers reinforcement ? what are its properties ?

Answer 40

Obtained by carbonizing polymers - Stiffness - Low density - Electrical conductivity

Question 41

What are plastic matrix ? what are its properties ?

Answer 41

They are used as matrices, they are referred to as resins - Durability - Lightness - Resilience - Low cost

Question 42

What are metallic matrix ? what are its properties ?

Answer 42

made from metals or alloys - Ductility - conductivity - stiffness

Question 43

What are ceramic matrix ? what are its properties ?

Answer 43

Made from ceramics, often glass - Durability - Heat resistance

Question 44

What does plastic act as matrix or reinforcement ?

Answer 44

Matrix

Question 45

What does fibreglass act as matrix or reinforcement ?

Answer 45

Reinforcement

Question 46

What type of degradation does metals and alloys face ? and why ?

Answer 46

They can oxidise (rust) or chemically alter if they are exposed to acid, rain, salt, oxygen

Question 47

What are 2 types of protection for metals and alloys against degradation ? and why ?

Answer 47

-Coating coat of paint because it block oxygen -Heat treatments :(hardening and tempering)

Question 48

What are some characteristics of decidous trees ?

Answer 48

loose leaves, hardwood

Question 49

What are some characteristics of conifers trees ?

Answer 49

needles , evergreen , softwood