Engineering office

The design of a cast component for investment casting can be launched on the basis of a sample, a sketch on paper, a 2D drawing, or a 3D design submitted by the customer. At this stage, it is often good for us to know the most essential shapes and dimensions of the component that have an impact on its performance. The aim is to keep these properties as unchanged as possible and modify other parts of the component to ensure good manufacturability of the investment-cast item. The objective in the design is to produce a casting that meets the customer’s requirements while keeping the manufacturing of the component economically feasible. It is good to remember that the quality of the final product largely depends on the level of co-operation between the customer and the foundry.

Since investment casting provides an opportunity to implement quite complex castings, it is advisable to consider whether yet another function should be added to the casting. The fewer parts there are in an assembly, the more reliable its function and the easier it is to keep the manufacturing costs down.

Casting-simulation software is an important tool for designers of investment-cast products. Simulation is used for ensuring manufacturability. It enables us to test how the shape of the component and for example the location of a hole will affect the internal quality of the casting. Simulation can be employed even in the quotation phase. It is of particular importance before production of rapid prototypes or wax-injection tooling.

Simulation reveals what will actually happen during the casting process between pouring and solidification. It aids in meeting the high quality requirements set for the component and in minimising the production costs.

Rapid prototyping is an excellent instrument for rapid product development and market entry. Also, a investment-cast component can be produced by means of rapid-prototyping techniques when the functionality or durability of the investment-cast component in a device assembly is uncertain.

The method of rapid prototyping allows a ceramic shell to be made on top of a wax pattern, into which molten steel is poured after dewaxing. This way, a significant amount of time is saved, since the time required for creation of production tooling is eliminated. In this case, one rapidly produced prototype (wax model) needs to be made for each cast item. This production method is economically feasible for runs of 1–50 items.

The most important function at this stage in the process is the design of the wax-injection tooling. Smooth co-operation between those responsible for the design of the investment-cast item and the personnel handling the tooling design is essential. The capacity of the wax-injection tooling is determined in the course of the design process. The goal is to produce high-quality wax patterns at an efficient rate.

Before the tooling-design process begins, the estimated annual volume of casting production needs to be known. The number of cavities needed in the wax-injection tooling and, in certain respects, the structure of the tooling are determined on this basis. There are also other design considerations in the investment casting process, such as the design of various item fasteners, adjustment pieces, and gauges.

The production of manufacturing tooling is implemented by tool subcontractors – partners who have proved reliable – on the basis of 3D models. We have at our disposal the best machines for tooling manufacture and our subcontractors’ up-to-date professional expertise.

Tooling can be made of aluminium since the pressures and temperatures applied in injection of wax are relatively low.

A sample series is always manufactured for each new component. During its production, information is collected at various points in the process, to ensure that the manufacturing of production series can be as efficient as possible from the very beginning. The sample series components are always x-rayed to ensure that the pieces are of high quality.

Three to five items from the sample series undergo dimension control to ensure that the dimensions are in keeping with the drawings, and a measurement report is drawn up on the results, to be delivered to the customer.