Dissemination of IT for the Promotion of Materials Science (DoITPoMS)



There are 4 main ways of casting metals; sand casting, die casting, continuous casting and investment casting. Each has advantages and disadvantages, and is suited for producing different components or using different materials.
The Biot number predicts how a casting will solidify, and is equal to \(\frac{h}{K / L}\),
where: h = heat transfer coefficient
           L = length of the casting
           K = thermal conductivity

Commonly 3 zones form as the casting solidifies;

  • Chill zone – small crystals form on mould wall.
  • Columnar zone – larger grains growing in optimum crystallographic orientations.
  • Equiaxed zone – small grains that solidified early but detached and moved back into the liquid.