Intro

Question 1

Define Toughness

Answer 1

Measure of the amount of energy a material can absorb before fracturing

Question 2

Toughness Equation

Answer 2

Energy Stored / Unit Volume

Units: Jm^-3

Question 3

3 Main Types of welding

Answer 3

Arc Welding, Torch Welding, Resistance Welding

Question 4

Arc Welding

Answer 4

Uses electricity to melt base metal (3000-20000 degress C)

Question 5

Torch Welding

Answer 5

Uses welding rod and open flame to melt metal

Question 6

Resistance Welding

Answer 6

Uses heat generated by resistance to an electrical current

Question 7

What is Poisson’s ratio?

Answer 7

The ratio of the lateral strain to the tensile strain:

v= -(lateral strain)/(tensile strain)

Question 8

Define Concrete

Answer 8

Ceramic composite material, composed of a a coarse granular material embedded on a hard matrix of a cement paste.

Question 9

Uses for Concrete

Answer 9

Structural Building such as bridges, buildings, dams and road pavement

Question 10

What are Corrosion and Heat Resistant steels?

Answer 10

Otherwise known as stainless steels, they are Iron alloys with at least 11.5wt%Cr

Question 11

Why are corrosion resistant steels corrosion resistant?

Answer 11

Because the Chromium in it oxidises more preferentially to Iron oxides (rust)

Question 12

What is Hardness?

Answer 12

Hardness is a measure of the resistance of a material to permanent deformation

Question 13

Give the Vickers hardness equation

Answer 13

HV= 1.854P/d^2

Where P is the applied force and d is the mean of the diagonals of the indentation

Question 14

Info on Concrete reinforcement

Answer 14

Concrete’s tensile strength is 10 to 15 times lower than its compressive strength.
Meaning it’s usually cast containing steel bars if the application means it will be subject to tensile forces

Question 15

How is Cement made?

Answer 15

The raw materials are ground, blended and fed into rotary kilns fired by gas, oil or usually coal.

Question 16

Formula to remember

Answer 16

C3S2.3H20

Question 17

Define Glass

Answer 17

Inorganic product of fusion which has been cooled to a rigid condition without crystallisation.

Question 18

What is the lever rule?

Answer 18

Weight fraction of solid and liquid in equilibrium at a set temperature equal one.

Question 19

Weight fraction of solid equation

Answer 19

Fs=(Co-Cl)/(Cs-Cl)

Question 20

Weight fraction of Liquid equation

Answer 20

Fl=(Cs-Co)/(Cs-Cl)

Question 21

What are Steels?

Answer 21

Iron-Carbon alloys containing less than 2wt%C but usually containing around 0.8%

Question 22

What phase transformations are associated with Steel?

Answer 22

austenite, cementite, ferrite

Associated with the iron rich corner of the Fe-Fe3C phase diagram

Question 23

Low carbon Steel

Answer 23

up to 0.25wt%C, used for cans, pressings, wires, nails

Question 24

Medium Carbon Steel

Answer 24

between 0.25 and 0.6wt%C, used for Wire rope, Gears, axles, forging, castings, springs

Question 25

High Carbon Steel

Answer 25

Up to 0.6wt%C, Used for tools, ball bearings, dies and piano wire

Question 26

Hume Rothery Rules

Answer 26

Conditions required for complete solid solubility:
Same crystal structure,
Atomic dimensions differ by no more than 15%
Same valency

Question 27

What does the second hume rothery rule mean?

Answer 27

Only substitutional solutes can be found in complete solid solubility

Question 28

Youngs Modulus

Answer 28

Stress/Strain,

Gradient of stress strain curve in the elastic reigon

Question 29

Stress

Answer 29

Force/Area

Question 30

Strain

Answer 30

Extension/Original length

Question 31

Polycrystalline

Answer 31

More than one crystal, meaning grain boundaries are present

Question 32

Single Crystal

Answer 32

No grain boundaries, one crystal

Question 33

Raw materials in cement

Answer 33

Lime, Silica, Alumina, Iron Oxide