· Aleaciones ligeras ·
M. J. Ainsworth1 and W. D. Griffiths2
1Gemco Cast Metal Technology, The Netherlands. 2 School of Engineering, University of Birmingham, UK
67th World Foundry Congress
In the Lost Foam casting process the filling of vertically oriented plates
was viewed using a real-time X-ray technique to examine the interaction of
the cast Al with the polystyrene foam pattern. The plates were cast by
means of a counter-gravity technique and bottom-gated running system.
Real-time X-ray images showed that the advancing metal front was
associated with the development of finger-like protrusions as mould filling
velocity was increased. This inevitably led to the entrapment of the
degradation products of the polystyrene pattern. Tensile properties of the
plates showed a significant reduction when an unstable metal front was
present during filling.
A similar type of instability was encountered during the displacement of
liquid glucose by mercury in a Hele-Shaw cell. This analogue model of the
process can be used to discover the conditions under which interface
instability can occur in the Lost Foam casting process.
