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PM Bill 1 - Coggle Diagram

- - - - Mould is made in two halves
    - - Automated sand casting
      - Really large expensive machine, removal of mould boxes,
      - Sand has higher strength than traditional
  - - - Liquid metal poured into mould and flows under gravity, die is resistant to thermal shock, die temp of 300C, internal interfaces of die sprayed with refractory material to reduce heat transfer (2-3m/s)
    - - Die is placed over a sealed furnace that is then pressurised to force metal upwards into die (0.5m/s)
      - Dies are coated in graphite for smooth finish, capable of high quality as no oxide skins or air entrapment
    - - Piston pushes metal into mould at 40-50m/s, metal is nearly atomised.
      - Causes much internal porosity but produces good surface finish and thin walls
- - - - Feeder is used to fill central hotspot
    - - Dip in the surface
  - - - Waiting: melt is held at low temp and hydrogen diffuses out then reheated
      - Degassing: Passing inert gas bubbles through the melt and H diffuses into the bubbles from melt
      - Chlorine: Cl reacts with Al to form gas and degasses. Not widely used as toxic
      - Hexachloroethane: breaks down to form chlorine gas and works same as chlorine
      - Vacuum degassing: Put it in vacuum and wait
        Sievert law: \(H= S_0 \sqrt{P_{H_2}}\)
      - Lance degassing: same as degassing but with a lance
      - Rotary degassing: same as lance but it go spinny spin :check: