Semi-solid Processing of Engineering Alloys by a Twin-screw Rheomoulding Process
Based on the extensive experience in injection moulding of polymeric materials, a
twin-screw rheomoulding process has been developed for semi-solid metal (SSM) processing
of engineering alloys. In this process, a liquid alloy is fed into a twin-screw extruder, where
the liquid alloy is sheared and cooled to a temperature between its liquidus and solidus to
produce the desirable SSM slurry. The sheared semi-solid slurry is then transferred to a
mould cavity for component shaping. The experimental results of rheomoulded alloys have
demonstrated that, compared with other existing SSM processing techniques, the twin-screw
rheomoulding process has many advantages, including production of fine and spherical solid
particles distributed uniformly in the matrix, accurate control over a large range of solid
volume fractions, easy operation, shorter cycle time and lower overall component cost.
Zhongyun FAN, Shouxun JI, Mike J. BEVIS
Reçu le 1 juillet 2001.
Accepté le 15 octobre 2001.
Semi-solid, metals, processing, rheomoulding, microstructure.