Precision Casting

The casting method of choice for complex components. 

The Exacast® ceramic precision casting process is an interesting alternative to casting methods like investment casting and shell moulding. The Exacast Process was developed by Wolfensberger and registered under the Exacast® brand name. As the name suggests our precision casting process allows for the accurate casting of complex components. Reusable patterns made of plastic, metal, wood or silicone rubber are coated with a quick-hardening ceramic and then fired. The alloy that is then cast into the preheated moulds is able to flow into extremely thin walled sections. A wide choice of steel and cast iron alloys can be cast as per customer requirements.

Our Strengths – Your Benefit

The Process For Complex Castings.

  • First-class surface roughness: N8/N9 (Ra 3.2 - 6.3 µm) 
  • Tolerances in accordance with VDG instruction sheet P 690 for investment casting
  • Radii > R 0.2
  • Large wall thickness differences possible 
  • Weight of parts 2 to 400 kg 
  • Size of parts up to 1000 x 1000 x 400 mm 
  • Up to 100 cast iron and steel materials

Tolerances In The Exacast® Precision Casting Process.

The tolerances for Exacast® precision casting are based on VDG instruction sheet P 690 for investment casting. The tolerances specified in the sheet can be largely complied with. The only non-compliance that occurs relates to the non form-bound dimensions, for example over the mould partition or from the core mould to the outer mould, and even these do not exceed D1 in VDG standard P 690. If the precision casting tolerance is not adequate, a machining allowance must be added .

 

 

Precision Casting References

Precision Casting Exacast® Products

IMPELLER GUIDE WHEEL

Characteristics

Unit weight: 5 to 100 kg
Material: G-X 5 CrNi 19-10 (1.4308),
Batch size: 5 to 100 pieces

Target Setting

Hydraulic pump parts with high finish quality, strict tolerances, complicated blade geometry, minimal post-machining.

Solution

With Ra 3.2 to 6.3 µm in the pre-cast interior spaces that are practically inaccessible for machining, there is a very high level of effectiveness, optimal shaping of even the thinnest blade parts beside thick-walled areas and high flexibility in terms of material and shape variations (e.g. diameters from 200 to 800 mm). Delivery with inspection certificate.

BLOWER WHEEL

Characteristics

Unit weight: 1.3 kg
Material: EN-GJN-HU600 (EN-JN 3049) (previously G-X300 CrMo 271)
Batch size: 100 pieces

Target Setting

Very high wear resistance for use as a blower wheel in a blast cleaning machine for cleaning concrete surfaces.

Solution

Wear-resistant carbide alloy cast iron in ceramic moulds. Subsequent hardening to at least 60 HRC. High tolerance and minimal imbalance without any post-machining.

CENTRIFUGE

Characteristics

Unit weight: 1 to 5 kg
Material: GJS-400-15 (EN-JS103), (spheroidal graphite iron)
Batch size: 100 or 200 pieces

Target Setting

Efficient production of a complicated part with high quality requirements. Used in turbo chargers to centrifuge the cleaning oil for ball bearing lubrication.

Solution

Very good surface (Ra 3.2 to 6.3 µm) of the finally cast interior section. Large variations in wall thickness from the three thin ribs in the oil section to a solid external contour.