Development

During the new product development phase, state-of-the-art tools like rapid prototyping technologies, computer aided solidification simulation and computer aided design are used to determine the optimal process parameters to make the requested part feasible as per customer metallurgical and dimensional requirements. Based on customer supplied specifications and 3D model along with a 2D inspection drawing.

Tooling

The tooling is built to customer-provided drawings, 3D-Models and specifications. Tooling dimensions will take in account the shrink factors of the geometry of the part all along the IC-Process. The shrink factors depends on the process and the materials used. They are unique for every foundry.

Ceramic Cores

Ceramic cores may be used to form specific internal cavities of the pattern. They represent a big part of our know-how and are produced internally. Depending on the IC-process different materials may be used.

Wax injection

To produce a wax reproduction (wax pattern) of the customer supplied part number the tool is injected with specially-formulated wax.

Cluster assembly

Once the wax patterns are produced, they are assembled onto the gating system and sprue  to form a cluster.

Shell building

The cluster is dipped into a slurry of fine ceramic particles, coated with a fine grain sand and then dried to form a ceramic shell around the patterns and gating system. This process is repeated (shell layers) until the shell is thick enough to withstand the following process steps. This part of the process is fully automated.

Dewaxing (Autoclave/Flashfiring)

Once the ceramic shell has been dried, it is placed in a steam autoclave to remove  the most part of the wax. Any wax residual is then removed by further treatment in furnace at high temperature,  this further treatment is also effective to develop strength of the ceramic. The mould is now available for the casting process.

Mould insulation

Before to move the moulds to the casting process they have to be insulated using a refractory wrap to be properly applied on the mould surface.

The aim is to mange the cooling of the mould and consequently to lead the solidification path of the alloy as needed to get sound castings.

Pre heat

Pre heating of the mould at high temperature before pouring is needed for different reasons:

- Develop further strength of ceramic
- Avoid thermal shock on ceramic with possible mould cracking
- Create proper conditions to have a good filling of the mould

Pouring

The  preheated mold is filled with molten metal poured from a ceramic crucible  where the charge ingot is heated and melted by Induction Melting. Most of the applications in Precicast are poured under vacuum in order to reduce the oxidation and promote proper filling.

Cooling

Afterthe mold has been filled, the molten metal is allowed to cool and solidify into the mould where it will get the final casting shape

Knockout and Cutoff

Once the casting has cooled at room temperature, the ceramic shell is broken off (knock-out) and the individual castings are cut away from the gating system.

Finishing

Castings surfaces, if needed due to some surface defects or gate residuals,  are reconditioned to fit customer roughness and dimensional requirements

Heat treatment / HIP (Hot Isostatic Pressure)

Hot Isostatic Pressure (HIP) is applied when reduction of shrinkage porosity is needed

- Air of vacuum heating  at specific temperature followed by proper cooling conditions, is generally applied to improve microstructure

- Aim of both Heat Treatment, also in combination, is to increase mechanical properties of the castings.

Inspection

To check the soundness of the castings they are inspected by several nondestructive testing like X-Ray, fluorescent penetrant inspection (FPI), grain morphology, crystallographic orientation (just for SC).

To check if dimensional requirements are reached, different procedures are applied like 3D mechanical scanning , 3D optical scanning or special gauges.

Wall thickness on hollowed part are also checked by ultra sonic control.

Packing and shipping

The castings are securely packed for the shipping to the customer or further suppliers

Precicast is optimizing logistics to reduce the overall costs with simultaneous adjustment of delivery times to the customer’s individual production requirements.