The effect of foam pattern density on castings

The effect of low density patterns on castings:

The low-density pattern will mainly cause a large shrinkage of the pattern  easy deformation, causing the casting size to be inconsistent with the drawing  insufficient machining allowance. When the density of pre-hair beads is low, the shape is  easy to be formed.

The influence of step density on castings:

The density of the foam-like material (±1g/l) has little effect on the flow pattern, while its density gradient has a greater effect on the flow pattern.

(1) When the density ladder is large: the white area is  easy to form,  the formed shape is easy to deform.

(2) When the density step is large: the pattern decomposition  gasification speed are different during the casting process, which is easy to produce local carbon defects in the casting  uneven distribution of the carbon in the casting, resulting in the scrap of the casting.