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Flashcards in Intro Deck (33):
1

Define Toughness

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

2

Toughness Equation

Energy Stored / Unit Volume
Units: Jm^-3

3

3 Main Types of welding

Arc Welding, Torch Welding, Resistance Welding

4

Arc Welding

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

5

Torch Welding

Uses welding rod and open flame to melt metal

6

Resistance Welding

Uses heat generated by resistance to an electrical current

7

What is Poisson's ratio?

The ratio of the lateral strain to the tensile strain:
v= -(lateral strain)/(tensile strain)

8

Define Concrete

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

9

Uses for Concrete

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

10

What are Corrosion and Heat Resistant steels?

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

11

Why are corrosion resistant steels corrosion resistant?

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

12

What is Hardness?

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

13

Give the Vickers hardness equation

HV= 1.854P/d^2
Where P is the applied force and d is the mean of the diagonals of the indentation

14

Info on Concrete reinforcement

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

15

How is Cement made?

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

16

Formula to remember

C3S2.3H20

17

Define Glass

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

18

What is the lever rule?

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

19

Weight fraction of solid equation

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

20

Weight fraction of Liquid equation

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

21

What are Steels?

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

22

What phase transformations are associated with Steel?

austenite, cementite, ferrite
Associated with the iron rich corner of the Fe-Fe3C phase diagram

23

Low carbon Steel

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

24

Medium Carbon Steel

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

25

High Carbon Steel

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

26

Hume Rothery Rules

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

27

What does the second hume rothery rule mean?

Only substitutional solutes can be found in complete solid solubility

28

Youngs Modulus

Stress/Strain,
Gradient of stress strain curve in the elastic reigon

29

Stress

Force/Area

30

Strain

Extension/Original length

31

Polycrystalline

More than one crystal, meaning grain boundaries are present

32

Single Crystal

No grain boundaries, one crystal

33

Raw materials in cement

Lime, Silica, Alumina, Iron Oxide