Rheocasting with destructable cores

Important results from the project

The main purpose of the project was to find out the most suitable binder system for using sand cores in rheocasting processes. Cores made with PU Coldbox are stable during handling and casting. We haven’t, however, received a surface quality that is good enough for liquid transport. The project’s goal - to increase the market for Rheocasting - is not yet achieved. We need cores with a combination of strength and good breakdown properties, giving clean inner surfaces.

Expected long term effects

We could successfully find a suitable binder system for sand cores that can stand by the melt filling pressure and melt erosion in Rheo-casting process. However, we could not achieve an acceptable surface quality in castings with sand cores. Improving the surface quality needs more investigations. The expected effects depend largely on what quality the inner surfaces can yield.

Approach and implementation

Discussions with supplier company Karlebo and experts from Swecast. Three different binder systems were chosen. A corebox for the trials was manufactured. Cores were produced, using the three chosen binder systems. Casting trials showed that two of the systems were too weak for handling and casting. Discussions with a leading producer of sand core binders (ASK), with the purpose of getting better surfaces inside the castings. Some improvements were seen at the end of the project. Work still remains.