Rheocasting trials at GTK in Kassel

Last week, I was at the GTK to support them with a trial program. It is great to see the increasing interest in Rheocasting. For the final customer, it wasn’t the first encounter with a Rheocasting technique. But they were really happy to see a stable process from the Comptech Rheometal process.

Of course, having a stable Rheocasting process does not matter. All the other Rheocasting processes work on temperature control. To set the correct temperature every time, the cooling has to be adapted for every change in chemical composition. So you have to change process parameters with every new melt. Even then, the problems don’t stop. The temperature range that has to be homogeneously reached is within 0.1 Kelvin. Good luck reaching that every time.

For the AlSi7Mg0.3, the slurry temperature difference between a slurry with a low and a high fraction solid is 0.8 Kelvin. No cooling solution exists that can cool multiple kilos of aluminium within seconds to that precision.
On the other hand, the Comptech Rheometal process uses its EEM (Enthalpy Exchange Mass) to cool the melt. The EEM melts off and cools the melt that way. The EEM is produced from the same melt and has the same enthalpy. So, when the chemical composition changes, the enthalpy changes as well, and this makes that process mass-controlled and not temperature-controlled.

Going back to the example from above, the 0,8 Kelvin temperature difference in the slurry was caused by changing the EEM height by 22 mm by adjusting the gravity die is stable and easy to control. Watch the speedrun of the Rheometal process in the video. You can see the process with your own eyes.

If you are interested in Rheocasting yourself, take a look at the Rheocasting Workshop. Schedule a free consultation today to get your Rheocasting journey started.