Materials: Constraints & Deformations

Question 1

What is a constraint?

Answer 1

It is a force.

Question 2

What is a deformation and what are the different levels of deformation?

Answer 2

It is a constraint on an object

1. Elastic
2. Plastic
3. Fracture

Question 3

What are the five constraints?

Answer 3

1. tension
2. torsion
3. shearing (sharp)
4. compression
5. deflection

Question 4

Hardness?

Answer 4

resistance to being scratch.

Question 5

Resilience?

Answer 5

shock resistance.

Question 6

Malleability?

Answer 6

ability to be shaped.

Question 7

Ductility?

Answer 7

pulled/stretched into a wire using tension.

Question 8

stiffness?

Answer 8

ability to maintain shape.

Question 9

What are plastics made from?

Answer 9

fossil fuels (oil and gas)

Question 10

What are the building blocks of fossil fuels?

Answer 10

monomers, which make a chain called polymers which form different plastics.

Question 11

What are thermoplastics?

Answer 11

Plastics that can be shaped/molded/remolded when heated, which ends up hardening (heat–>recycle–>new plastic)

Question 12

What are thermosetting?

Answer 12

Non recyclable permanently set plastics.

Question 13

What are two signs of degradation in plastics?

Answer 13

1. crack

2. change in color

Question 14

How to protect plastics from degradation?

Answer 14

1. oxidation
2. penetration of liquid (waterproof coating)
3. ultraviolet rays

Question 15

How do you create ceramics?

Answer 15

1. Heated (metals+nonmetals)
2. Let water evaporate
3. bonds rearrange
4. ceramics created!

Question 16

What are two signs of degradation in ceramics?

Answer 16

1. exposure to elements

2. thermal shock

Question 17

What are composites?

Answer 17

alloys: reinforcement (skeleton) and matrix (fats)

Question 18

What are two signs of degradation in composites?

Answer 18

1. deformation of matrix and reinforcement

2. matrix and reinforcement don’t hold together

Question 19

What is the sign of degradation in metals and alloys?

Answer 19

they can rust/oxidize.

Question 20

What are 3 types of treatments to protect metals and alloys from degradation?

Answer 20

1. coating
2. quench hardening and tempering
3. annealing

Question 21

What is quench hardening and tempering?

Answer 21

heat treatments used on alloys to rearrange atoms to produce a harder steel.

Question 22

What is annealing?

Answer 22

after being deformed by welding it restores the original properties of steel.

Question 23

What is a sign of degradation in woods?

Answer 23

fungi, microorganisms & insects feed off of wood.

Question 24

How can we protect woods from degradation?

Answer 24

1. coat it

2. high heat treatment