The Rapid Casting is based on the combination of Rapid Prototyping, to manufacture a disaposable pattern (SLS + Windform PS), and “Investment Casting” (lost wax casting).
The Research and Development department of CRP Meccanica is involved in the technology of the Rapid Casting from 1997 improving the process and the materials involved.
In Rapid Casting the lost wax casting takes place with the use of disposable patterns made in Rapid Prototyping, with the overlapping of layers of polymeric material (Selective Laser Sintering).
The system does not require supports because the piece stands thanks to non-sintered powders, giving free functional concept of the product (opposite to CNC).
The procedure of Rapid Casting involves:
- A disposable pattern made with RP and polystyrene material
- The pattern undergoes wax infiltrations to increase its strength and its dewaxing
- The pattern is immersed in a ceramic bath
- Slurries and stuccoing and exsiccation
- The lost pattern is evacuated: dewaxing with flash firing or in an autoclave and subsequent sintering of the ceramic shell
- Alloy casting with inductor or voltaic arc
- Pouring, cooling, reduction of the shell, shot peening, gate cutting, heat treatments
The final product is supplied fully CNC machined and complete of treatments.
The mostly processed alloys are: Titanium, Aluminium, Steel or Superalloys.
The advantages of Rapid Casting are:
- Isotropy compensation – the pieces coming from casting are more resistant and reliable because the CAE/FEM results (if correctly done) are much more near to the real cases than in the fabricated solution or in the machined from solid solution. This is possible only thanks to the isotropy for compensation.
- Higher resistance and piece reliability
- Higher freeform possibility
- Possibility to make the piece lighter (pocket features) and stiffer (rib features)