Hartley reported
a technique developed by GKN Technology in UK for
the pressurised solidi®cation of Al alloy in reusable
dies. In this process a die set is placed on a hydraulic press
and preheated, and the exact amount of molten alloy is
poured into the lower half of the open die set, the press
closed so that the alloy ®lls the cavity and the pressure
maintained until complete solidi®cation occurs (31±
108 MPa pressure).