At Vforge, we are expert at semi-solid thixocasting. That means we process aluminum alloys in the semi-solid state requiring specially prepared material and unique die and system designs. We do this because semi-solid flow offers very special, advantages over liquid casting.
For a start, semi-solid aluminum alloys are viscous (hence the “V” in our name) meaning that they do not splash and spray entering a die but rather fill the cavity with a smooth, quiescent, predictable flow. That in itself is a tremendous asset in avoiding trapped gases inside the parts. On top of that, because the semi-solid material is 65% solid at the time of injection, shrinkage porosity is also effectively eliminated.
In normal casting situations, when liquid aluminum transitions to solid in a mold or die, it contracts 6% by volume. Without any external means to fill that 6% deficit, so-called shrinkage cavities can occur. Our combination of semi-solid injection and high final pressures produces highly dense, pressure tight, heat-treatable parts.
But it gets better. Because semi-solid aluminum passes far less heat to the die than liquid aluminum, die life is longer, providing additional benefits to our customers by reducing ongoing tooling replacement costs.
