CASTABILITY MEASURES FOR DIECASTING ALLOYS: FLUIDITY, HOT TEARING, AND DIE SOLDERING

Abstract

Tautologically, castability is a critical requirement in any casting process. Traditionally, castability in sand
and permanent mold applications is thought to depend heavily on fluidity and hot tearing. Given
capital investments in dies, die soldering is a critical parameter to consider for diecasting. We discuss
quantitative and robust methods to insure repeatable metal casting for diecasting applications by investigating
these three areas. Weight reduction initiatives call for progressively thinner sections, which in turn
are dependent on reliable fluidity. Quantitative investigation of hot tearing is revealing how stress develops
and yields as alloys solidify, and this has implications on part distortion even when pressure-casting
methodologies preclude hot tearing failures.
Understanding the underlying mechanism of die soldering presents opportunities to develop methods
to avoid costly downtime and extend die life. Through an understanding of castability parameters,
greater control over the diecasting process can be achieved.