Understanding the Relationship Between Filling Pattern and Part Quality in Die Casting

Understanding the Relationship Between Filling Pattern
and Part Quality in Die Casting

1.0 Introduction
The overall objective of this research project was to investigate phenomena involved in the
filling of die cavities with molten alloy in the cold chamber die-casting process. It has long been
recognized that the filling pattern of molten metal entering a die cavity influences the quality of
die-cast parts. Filling pattern may be described as the progression of molten metal filling the die
cavity geometry as a function of time. The location, size and geometric configuration of points
of metal entry (gates), as well as the geometry of the casting cavity itself, have great influence on
filling patterns. Knowledge of the anticipated filling patterns in die-castings is important for
designers. Locating gates to avoid undesirable flow patterns that may entrap air in the casting is
critical to casting quality – as is locating vents to allow air to escape from the cavity (last places
to fill). Casting quality attributes that are commonly flow related are non-fills, poor surface
finish, internal porosity due to trapped air, cold shuts, cold laps, flow lines, casting skin de-
lamination (flaking), and blistering during thermal treatment more...