Matrix Material Flashcards
What are the properties of Aluminium Alloys (Matrix)?
Density: 2,700 kg/m3
Melting Point: 660 Degrees.
Young’s Modulus: 75 GPa
Quite reactive.
What are the properties of Magnesium Alloys (Matrix)?
- Density: 1,700 kg/m3.
- Melting Point: 650 degrees
- Young’s Modulus: 45 GPa
- Very reactive
- Cast alloys with Al, Mn
Strength 200 MPa / Elongation 11% - Aircraft forging alloys with Zn, Zr
Strength 350 MPa / Elongation 5%
What are the properties of Titanium Alloys (Matrix)?
- Density: 4,500 kg/m3
- Melting point: 1668 degrees
- Young’s Modulus: 107 GPa
- Quite reactive at high temperature.
What are the properties of Pure Titanium, Alpha Titanium, Beta Titanium (Matrix)?
Pure Titanium: Strength 450 MPa / Elongation 25%
Alpha Titanium (with Al, Sn): Strength 800 MPa / Elongation 16%
Beta Titanium (with V, Fe, Al): Strength 1200 MPa / Elongation 10%
From Mg, Al, and Ti metal matrix what has the lowest density to highest?
- Mg alloys
- Al Alloys
- Ti Alloys
From Mg, Al, and Ti metal matrix what has the cheapest to expensive?
- AI alloys
- Mg Alloys
- Ti alloys
From Mg, Al, and Ti metal matrix what has the greater stiffness to lowest?
- Ti alloys
- Al alloys
- Mg alloys
From Mg, Al, and Ti metal matrix what has the highest temperature resistance to lowest?
- Ti alloys
- Mg alloys and AI alloys
From Mg, Al, and Ti metal matrix what has the highest strength to lowest?
- Ti alloys
- Mg alloys and AI alloys
What are the properties of Aluminium Oxide (Alumina) Ceramic?
Density: 3,900 kg/m3
Melting Points: 2045 degree
Young’s Modulus: 340 GPa
Strength: ~ 400 MPa
Toughness: 4 MPam^(1/2)
What are the properties of Zirconium Oxide (zirconia) Ceramic?
Alloyed with magnesium (or ytrrium) oxide for extra toughness
- Density: 5,700 kg/m3
- Melting Point: 2660 degrees
- Young’s Modulus: 205 GPa
- Strength: ~400 MPa
- Toughness: 4 MPam ^(1/2)
What are the properties of Glass Ceramic?
Most commonly lithium aluminosilicates (LAS)
- Density: 3,500 kg/m3
- Melting Point: ~1300 degree
- Young’s Modulus: 80 GPa
- Strength: ~150 MPa
- Toughness: 1.5 MPam^ (1/2)
What are the properties of Carbon (ceramic)?
- Large variations in structure, and properties.
- Main benefit - very high temperature strength (with no oxygen!).
- With oxygen, oxidises from 400 degress.
From Glass, alumina and zirconia ceramic matrix what has the lowest density to highest?
- Glass ceramics
- Alumina
- Zirconia
From Glass, alumina and zirconia ceramic matrix what has the highest to lowest strength?
- Alumina and Zirconia
- Glass ceramic
From Glass, alumina and zirconia ceramic matrix what has the lowest stiffness to highest?
- Alumina
- Zirconia
- Glass Ceramics
What are the step reaction of Polymerisation?
- Involves reactions between functional groups (on both ends of a monomer.
- If we have more than 2 functional groups on a monomer, we can get branching and crosslinking, producing a thermoset.
- Reaction started by mixing 2 components, or a high T.
- Extended pre-polymers can also be crosslinked using double bonds.
- Most common example is with styrene.
- This often requires catalysts (often peroxide-based) to start the crosslinking.
What are polyester resins?
Ester links between acid and alcohol groups.
Acid + Alcohol = Ester
How are polyester resin formed?
- To form polyesters, we need to have acid and alcohol groups at both ends.
- So we use a di-alcohol (known as a glycol) and di -acid.
- This gives us linear polyesters, that we can’t cross-link (so are thermoplastics).
- For useful polyester resins, we use an acid anhydride, giving double bonds.
How are double bonds linked?
The polyester with double bonds (unsaturated polyester) is cross linked with styrene.
This normally needs a peroxide-based catalyst.
For polyester resin, what do practical systems have?
Unsaturated polyester:
- Supplied mixed with styrene.
- Acts as a solvent to reduce viscosity.
- Allows crosslinking.
Adding a catalyst (peroxide-based) starts cross-linking, normally at room temperature.
What are the advantages of polyester resin?
- Low cost
- Easy processing
- Reasonably mechanical properties
What are the disadvantages of polyester resin?
- Poor toughness
- Low temperature resistance
- Poor resistance to alkalis
What are the applications of polyester resin?
Widely used general purpose resin for automotive, marine, construction sectors.
