Precision casting
Specialist in preciosion investment castings
The lost wax method is very suitable for producing precision castings with complex shapes and high dimensional accuracy & quality. In addition, it offers a large freedom in both design and material choice of your desired castings. Precision castings are known as the highest quality castings available on the market.
Why castings from CIREX
CIREX is your reliable partner in the field of precision investment castings and highly values a good client relationship. In good cooperation with you as our customer, we would like to act as a development partner, sharing our thoughts and ideas about product design, material choice, measurements or machining.
All of this is matched exactly to your wishes and demands. Achieving an optimal casting through joint dialogue is our general principle. The degree of co-development is decisive in your project’s success.
LOST WAX CASTING
Phase 1: Mould engineering & production
Precision investment casting starts with the engineering & production of a casting mould, also known as a wax tool. This mould is home-developed by CIREX engineers and serves as a ‘negative’ of the final casting. With use of a casting mould a wax model can be sprayed with a very accurate dimension and an excellent contour sharpness. These wax models are glued together onto a so-called wax ‘tree’ on which a casting funnel is mounted. In a later stage of the process, steel is poured into the funnel. Depending on the size of the series, the mould is installed either onto a manual or automatic press.
Phase 2: Ceramics
After the wax models are glued together, the tree is given a fireproof ceramic shell. This shell is constructed by repeatedly submerging the tree (up to 7 or 9 times) in a slurry and sprinkle it with ceramic sand. The ceramic layers are then hardened in a drying chamber, exposed to air.
After the layers have been formed and dried, the wax is melted out of the ceramic tree by using steam (120°C) in an autoclave. This is why it is called ‘lost wax casting’. The molten wax can be regenerated and is reusable. The ceramic tree is then baked at a high temperature (1100°C) and reaches its final strength through the sintering process. Wax leftovers are burned up during this process.
Phase 3: Casting process
The desired steel alloy is melted in a large furnace and brought to casting temperature. The ceramic tree is, at the same time, heated in a oven to prevent thermal shocks during the casting process. After the tree has been heated, it is removed from the oven by a robotic arm and the steel is poured in by means of counter gravity. When the trees have been cast, they have to be cooled on a cooling conveyor (with nitrogen). The trees are then removed from their ceramic shells, by breaking the shell with a fully-automatic knock-off hammer. This removes most of the ceramic.
Phase 4: Finishing & Machining
The remainder of the ceramic is removed in the Finishing Department by means of steel, sand and/or water blasting. The next step involves sawing or vibrating the products off from the steel tree. The steel leftovers are sorted on alloy and may be melted again during the next casting badge. Finally, the ingate is sanded off, the product is machined, calibrated or heat-treated when necessary. After the final inspection, the products are ready for shipment to another satisfied CIREX customer.
PRECISION INVESTMENT CASTING IN DIFFERENT INDUSTRIES
The lost wax method lends itself perfectly to produce investment castings in large and medium series. These castings can be applied in a wide range of industries, which widens CIREX industry reach. CIREX customers operate in the following industries:
Automotive
For renowned car manufacturers, CIREX delivers precision investment castings which are used in engines, bodyworks , gearboxes and brake & fuel systems. Some examples of the products delivered by CIREX are: rocker arms (engines), fuel pumps (engine) and shift cylinders (gear box).
Pharmaceutical & Food
Within the Pharma & Food industry, CIREX delivers a wide range of high quality components. Especially decisive in this industry are the low roughness values, the precise tolerances and the available selection of special steel alloys. Particularly in the food industry, a low roughness value is essential to ensure no bacterial growth can manifest when the surface is too rough. In addition, most of the precision castings are made of stainless steel to avoid the risk of corrosion (rust) and to ensure hygiene is secured after the castings come in contact with water. Examples of precision investment castings delivered by CIREX are: impellers for industrial pumps, and ball valves & valve houses for paint mixers.
Petrochemical
The castings delivered by CIREX to her customers in the petrochemical industry consist, for example, of rotors & stators for drilling systems, or burner heads which are mounted on gas burners. Accuracy and sustainability of these precision castings are often the deciding factor when it comes to choosing for lost wax investment casting.
Process technologie
CIREX is a key player within the process industry when it comes to precision investment casting. CIREX has developed many components, which are often cast into special alloys. These special alloys are applied because the components usually operate in environments that are either aggressive (hostile), subjected to large differences in temperature or products that are required to be immensely tough, strong or light. Some examples of products delivered by CIREX are: synchronous transmissions for hydraulic systems and grid plates for filter systems.
