Getting It Right the First Time

Risering of castings is supported through the determination of the local thermal modulus. This modulus describes the relationship between the heat content of a volume and the cooling power of the surrounding surfaces. For example, the hot spot with the largest thermal modulus (in this case 1.13 cm) must be fed by a riser with a higher modulus.

Starting from this initial information about the cast component, the gating and risering can be completed, with runner bars, chills and risers. The goal is a directed solidification into the risers. That means the last areas to solidify should be in the risers, not the casting.

The position and sizes of chills and risers are changed until the desired solidification path is reached and simulation shows a casting free of porosity. This way, the casting can be produced right the first time, and time and cost-intensive trials can be avoided.

Thermal modulus of the component shown in a cross-section (left), simulation shows the solidification path in the gated and risered casting (middle), the compressor housing is cast right the first time (right)

* Courtesy vonRoll Casting, Switzerland