Technology

Tools for wax injection

All tools for wax injection are designed in-house and fabricated in the tool-making department of the Company. The design of components and the runner system is based on the experience of our metallurgists and technologist and aided by sophisticated CAD/CAM/CEA tools.

Wax patterns and components

Wax patterns and components of the runner system are injected on a wax injection machine using tools developed and produced in house. Patterns and runner systems are manually assembled in a wax tree by gluing and welding of wax.

The shelling process

Once the wax trees are finished begins the shelling process, where several ceramic layers are applied in order to form a ceramic shell. In case of titanium, which is a reactive alloy the chemical composition of the ceramic material has to be appropriate in order to prevent a reaction during the casting. In between each layer the growing ceramic shell has to be dried in a controlled environment by means of temperature and humidity.

Ceramics preparation

When the shell is properly dry the wax is extracted and the ceramic is fired in order to obtain the appropriate properties to withstand the casting of titanium.

Titanium preparation

We use wide range of alloys, also raw material out of our own production of exhaust systems, but our base for offer is always customer's demand.

Vacuum casting

Before the casting the shell is additionally prepared and placed in a vacuum chamber of the melting unit. Because titanium is a reactive alloy (high affinity for other elements at elevated temperatures, especially in liquid state) it has to be cast in a vacuum. The ceramic shell is placed on a spinning table that rotates at high rpm, which enables us to cast thin wall parts and reduce the alpha case layer.

Finishing and inspection

After the casting process is finished, the ceramic shell is knocked out and casted parts are cut off from the runner system. In accordance with the intended use of a particular part it can be sandblasted as well as polished in a vibratory polishing machine in order to obtain the desired surface finishing. Casted parts are inspected using X-ray radioscopy and controlled by other non-destructive methods (dimensional measurement, surface roughness, visual inspection, liquid penetrant test, etc.) and destructive methods (chemical analyses, gas analyses, tensile test, hardness measurements, etc.)

Dimensional inspection

We use rapid prototyping technology (Dimension 3D printer) for design optimization and tool production, as well as for ‘reverse engineering’, for which measurements are performed using the:

- Zeiss Contura scanning machine,
- the GOM Atos IIe measuring camera
- the Romer Sigma scanning arm.