Wheel casting process - Turbotech

Impeller and compressor wheel casting process

Turbotech manufacture their aluminium impeller and compressor wheel castings to the highest standards due to the unique manufacturing process that has been developed by the team here at Turbotech. This is supplemented in production with state-of-the-art equipment from the start of the process to the final balancing of the wheels.

Lean manufacturing techniques are applied to all aspects of the Turbotech process to improve efficiency, quality of the product and also cost savings which can be passed on to our customers to create a value-for-money product. We include our whole workforce in establishing the processes that will add most value.

To meet the demands of the customer and the demands put upon them by industry standards, we feel it is essential to have the best equipment available and the highest possible control over our manufacturing process. This is why we have fully equipped ourselves to do the manufacture in house, aside from hipping which is sub-contracted.

Tooling

Copper mould cavities are used to make rubber patterns for any new types of wheel. This ensures the most repeatable quality and definition and a long tool life.

Rotary Degassing

Metal preparation is paramount and the latest rotary degassing techniques are employed when melting the aluminium to ensure the cleanest possible material.

Metal Filtration

Filtration techniques are employed as an additional precaution to eliminate oxides. An inert atmosphere is also employed during the pouring process.

Machining and balancing

Turbotech can provide fully finished impeller and Compressor Wheel Castings – machined and balanced in their new facility, ready for assembly into customer’s products ( to the turbocharger). A state-of-the-art balancing machine has been installed to enable on-site finishing to the high standards required by the industries we serve.

Rubber Pattern Production

Turbotech produce all their rubber patterns in-house using the latest techniques. This enables patterns to be replaced after a set number of castings have been produced to ensure that only prime quality patterns are used.

Counter-gravity Pouring

A smooth flow of metal into the mould is essential to minimise turbulence which would result in the formation of oxides. Turbotech use their own technique of counter gravity pouring which is controlled by computer.

Heat Treatment

Modern heat-treatment units are used with rapid quench facilities for all castings.

Hipping

Hot Isostatic Pressing (Hipping) is used where called for by customers. This process enhances the microstructure and fatigue properties of the castings.

A High Integrity Process

Only a few companies in the world have the capability to produce high quality aluminium impeller and compressor wheel castings. This is how we do it:

A rubber replica (or pattern) of the compressor wheel is produced in a metal die and this is covered by a specially formulated plaster slurry, to form a mould. After hardening, the rubber pattern is carefully removed, leaving the negative shape in the mould. The rubber patterns can be used many times but the plaster mould is only used once.
Aluminium is melted and then introduced into the mould to produce the cast component. After cooling, the plaster is removed from around the metal casting. The feeder system is cut away from the casting which is then cleaned by blasting. The casting is then processed further and finally heat-treated and inspected.
Depending on customer’s requirements, additional operations may include x-ray, dye-penetrant inspection, ultrasonic and other testing. Enhanced mechanical strength and fatigue properties can be achieved using hot isostatic pressing (HIP).
At this time, the raw casting can be machined, balanced and part-marked prior to shipment from our machine shop facilities

Need to know more?

Please contact a member of our team for further information about how we may be able to help you or to discuss your project in more detail.

Manufacturing & Process