Ordliste
Gravity die casting — definition
A casting process in which molten metal runs into a permanent metal mould under gravity, without applied pressure.
The fill is calm and takes seconds rather than milliseconds. Air has time to escape, and the section comes out sounder than in high pressure die casting.
The most important consequence is that the part survives heat treatment. That is why a load-bearing part with a high strength requirement often has to be gravity cast even though die casting would be faster and cheaper per part.
The drawbacks are a longer cycle (minutes per shot), a requirement for thicker walls and a rougher surface. The advantages are lower tooling cost and viability at considerably smaller series — typically a fifth to a tenth of what die casting requires.