These casting defects occur if the mechanical/thermal loads (stresses) exceed the moldability and the strength in the load cross-section. Scabbing then appears as irregular metallic crusts on the surface of the cast piece that are only a few millimeters thick and that usually have sharp edges and rough surfaces.
ASK Chemicals offers the following solutions with regard to products and expertise:
- Optimally activated bentonites
- Bentonite that is produced from multiple raw clay components and with an activation technique that is carefully coordinated to them in order to improve the technical properties of the mold. With the appropriate preparation, this yields the best wet tensile strength in the mold material mixture.
- Bentonite-carbon mixtures that feature the highest mold strengths in addition to the uniformity in various states of production that is typical for hybrid bentonites.
- Carbons that absorb compression stress in the wall of the mold by means of softening and swelling, which reduces the formation of scabbing
- Transferring expertise with regard to mold material preparation, control and checking
- Special binders and additives for core production and therefore avoiding core scabbing
- Optimum alcohol- and water-based coatings that are coordinated to the respective production range (molding base material, casting material)