Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AerospaceMetals > Titanium > Flashcards

Titanium Flashcards

1
Q

What are the sectors that use titanium?

A

Commercial aerospace
military aerospace
Power generation
CPI and Desalination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the advantages of titanium?

A

Low density
Excellent corrosion resistance
High melting point
High specific strength
Compatible with CFRP
Excellent properties at high temperatures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the disadvantages of Titanium

A

Expensive to machine
Low wear resistance
Difficult to form
Pick up of oxygen + nitrogen ^ 500*C
Expensive £25k/tonne
lots of work to remove oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Why is titanium with CFRP?

A

Similar linear expansion coefficient
Similar electrochemical potential
Can join easily - no galvonic corrosion
Similar youngs modulus (stifnnes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the order of the FFC cambridge process?

A
  1. Tio2 and MeOx
  2. Blend
  3. Press
  4. Sinter
  5. Electrochemical process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In FFC what are the components of the electrochemical process

A

Anode - Graphite
Cathode - TiO2/MeOx
Crucible - Titanium
Liquid - molten CaCl2 800-1100*C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What process is used for the extraction of titanium?

A

Kroll Process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the components of the Kroll process?

A
  1. Rutile + Chlorine + Coke
  2. Magnesium and TIckle
  3. MgCl2 off product
  4. Alloys and scrap added to sponge
  5. Electrode
  6. Melt process
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the general processing of titanium sponge?

A
  1. Titanium sponge
  2. Compaction
  3. Manufacture electrodes
  4. VAR (vacuum arc remelting)
  5. Ingots
  6. Breakdown Forging
  7. Blooms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some Alpha-Stabilising elements?

A

Aluminium
Oxygen
Nitrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the Beta-Stabilising elements?

A

Molybdenum
Iron
Vanadium
Chromium
Manganese

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does increasing Alpha stabilisers do?

A

Promotes alpha Phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can you promote the beta phase

A

Increase the quantity of beta stabilisers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the properties of Alpha dominant structures?

A

Higher Creep strength
Improved weldability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the properties of beta dominant structures?

A

Higher density
Increased heat treatment response
Higher short term strength
Increased strain rate sensitivity
Improved fabricability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is meant by the beta transus?

A

The temperature at which titanium alloy transforms from alpha to beta form

17
Q

What temperature is the beta transus

A

883*C

18
Q

What is the structure of the atoms before and after beta transus

A

before - BBC
after - HCP

19
Q

What is the effect of increasing interstitial elements on the properties of titanium?

A

Increases the tensile strength
Decreases the weld joint bend elongation

20
Q

What is the order of interstitial elements in terms of effect on properties?

A

N > O > C

21
Q

How can Alpha alloys be strengthened?

A
  1. Solution Strengthening from OXYGEN
  2. Grain Refinement (Hall Petch)
    3.Cold work
22
Q

What phase are non-heat treatable products?

A

Alpha
composition is such that beta cannot be retained at room temp in any form.
Always alpha
Martensite formed

23
Q

What are the applications of alpha alloys?

A

CLadding in chemical plants
Hydraulic piping
Cooling towers

24
Q

What are the benefits of Alpha Alloys

A

Highly corrosion resistant
Low maintanence cost

25
Q

What are the applications of near alpha alloys?

A

Compressor disks
Compressor blades
Gas turbine engines (compressor section)

26
Q

Why are near alpha alloys good for creep resistance?

A
  1. Silicon pins dislocations
  2. Large prior beta grain size - inhibits grain boundary sliding
  3. Alpha Structure - slow diffusion
    up to 600*C
27
Q

What are the applications of

A

Bulk heads for F22
High performance aircraft

28
Q

What are the benefits of Near beta alloys?

A

Good hardenability

29
Q

Applications of near beta alloys?

A

Landing gear components
Rotor hub for helicopters

30
Q

Benefits of Beta alloys

A

Cold formable
Omega formation surpassed

31
Q

What effect does grain size have on tensile strength?

A

Determines strength via Hall-Petch
grain size reduction ideal
Increase phase boundaries interfere with slip .
increased Yield Strength

32
Q

what effect do interstitial elements have on tensile strength

A

Deleterious effect on ductility
Have very potent solis solution strenghtening affect.

33
Q

What affect does age hardening have on tensile strength

A

hinders slip and increases strength.

34
Q

What is the microstructure influence on fracture toughness?

A

Lenticular morphologies provide a tortuous path for cracks
fine grain structure makes crack path easy
Fine grain structure have poor fracture toughness

35
Q

Microstructure influence on fatigue

A

Fine grain structure will have good crack initiaion resistance
Once crack has grown, microstructure ideal to have large grains to reduce ease of crack propogation

36
Q

Fatigue crack initiation resistance

A

Fine grain structure wanted
Stop crack initiation

37
Q

what is the most expensive part in the Kroll process

A

Thermomechanical process

38
Q

Heating Ti-6Al-4V above the beta transus for 4 hours followed by a furnace cool will lead to…

A

A single colony alpha structure and grain boundary alpha

39
Q

How are medium strength levels generated in CP-Ti alpha alloys?

A

Cold working

AerospaceMetals (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions