Schulung

Up to MAGMA C+M version 5.5.0, the erosion of core boxes was calculated as the dimensionless 'Mold Erosion' result. The sand velocity, the sand fraction, the impact angle and the duration of impact were considered, and as a result, a qualitative analysis of the local erosion in the core box was calculated. In MAGMA C+M version 5.5.1, the 'Mold Erosion' result has been replaced by the 'Erosion Depth' result, which shows the erosion depth in micrometers after a shot.

The erosion or material loss of the core box occurs due to the abrasion of the material, which is caused by continuous impact of sand grains under high speed on the core box surface. The extent to which erosion develops mainly depends on the following factors: impact conditions (sand velocity and impact angle), sand properties (density, sand grain shape and sand grain size) and material properties of the mold material (ductility, hardness and density).

Furthermore, the erosion properties of a ductile material are different from those of a brittle material.

For ductile materials, erosion increases up to the impact angle of about 30°, where the maximum is reached, and then decreases up to the 90° angle.

For brittle materials, erosion increases continuously up to the 90° impact angle, where the maximum is reached.

For an example with the sand H31, which has a "fully rounded" sand grain shape, you can see that the erosion depth for a steel or aluminum mold material increases based on the impact angle. Moreover, you can see that, for an impact angle of 15° to 45°, the erosion depth is about three times higher for the Al mold material used compared to the steel material.