The manufacture of sand molds for cast parts with especially thin layers (such as 0.15 mm) presents a great challenge for the construction of sand molds. The fact that this process can be completed on a fully automated basis and without tools based on CAD data is still marvelled at by many experts.
voxeljet was able to achieve this feat by building the sand mold for a clutch case for automotive specialist Koncast in Weilbach in less than five days using the layer building method.
The aluminum clutch case is used for the prototype of a vehicle clutch. It measures 465 mm x 390 mm x 175 mm and weighs 7.6 kilograms. The sand mold was produced at voxeljet using a 3D printer. voxeljet experts used especially fine GS09 quality sand to achieve the extremely thin layers for the sand mold.
Thin cast parts without Tools
The sand's finer resolution is particularly suitable for external moulds and provides optimum surface quality. In the z direction, accuracy is two times better than with the use of standard sand. "I was really surprised how smooth the process was, and how well the surface of the clutch case looked at the end of the process", reports Georg Rudolf, CEO of Koncast, who personally supervised the casting process.
The part was cast using the G-AlSi8Cu3 alloy as part of a normal production run with an oven temperature of 790°C and a cast temperature of approx. 760°C. The finishing treatment was applied at the blasting plant with steel balls. Overall, the process resulted in a clutch case with characteristics that were virtually identical to the series. Koncast also achieved enormous time and cost advantages, since the tool-less and automated 3D printing method does away with the customary manufacture of tools.
|Total size||697 x 525 x 353 mm||Total size||465 x 390 x 175 mm|
|Weight||145 kg||Weight||7.6 kg|
|Material||Sand||Lead time||3 weeks|
|Layer thickness||0.3 mm|
|Lead time||5 days|
|Build time||10 hours|