for topic test Flashcards
What heat treatments can be used for non-ferrous alloys?
- Annealing (same as ferrous)
- Precipitation hardening
What heat treatments can be used for ferrous metals? (from pink and blue sheets)
- Annealing
- Process annealing
- Normalising
- Hardening and tempering
- Surface hardening carburising
- Surface hardening nitriding
- Induction hardening
Explain the properties/formation of different types of steel microstructures (ferrite, austenite, cementite, pearlite, martensite).
Ferrite: soft and ductile. BCC.
Austenite: forms at red heat. FCC. soft and ductile, denser than BCC.
Cementite: forms when cooling from red heat (austenite). Fe3C. Extremely hard and brittle.
Pearlite: lamellar structure of ferrite and cementite. hard and strong
Give some examples of non-ferrous alloys.
Alloys of magnesium, aluminium, copper, titanium and nickel.
What are the three hardness tests?
Brinell - B ball - Tungsten carbide ball forced into surface
Vickers - V - diamond pyramid forced into. more accurate
Rockwell - well - depth of penetration. more convenient.
What are the different kinds of impact tests?
Notched bar: sudden blow, tendency for brittleness
Height of pendulum after striking:
Izod: I vertical
Charpy: h horizontal and higher
What are bend tests?
Tests done when the material can’t be tested normally (brittle ceramics, soft wood)
Surface stress in the beam at failure.
What are some ceramic forming processes?
- Extrusion (pipes)
- Jiggering (bowls)
- Slip casting (hollow products)
- Tape casting (thin products)
- Dust pressing (spark plug)
What are some polymer manufacturing processes?
- Blow moulding
- Extrusion
- Thermoforming (heated thermo-softening sheets are placed over dies to produce the required shape)
- Calendaring (rollers)
- Rotational moulding
- Injection moulding (common - bicycle seats)
What are some ferrous manufacturing processes?
- Forging
- Rolling
- Casting
- Extrusion
- Powder forming (ground - cold pressed - sintered)
- Welding
