‘Hybrid’ toolmaking process can cut supply times in half

A Research team at Cardiff University’s Manufacturing Engineering Centre has developed a rapid hybrid tooling process to help industry squeeze lead times further in the race to reduce time-to-market.

The research focused on the requirements of tool strength, wear resistance, surface roughness and accuracy. The method is described as hybrid because it uses a combination of technologies previously viewed as processes for one-off prototype production only.Techniques include selective laser sintering, electro-discharge machining, and high-speed machining. Layered manufacturing — the use of a sintering station to build up the product with layers of plastic or metal powder — is another approach.

The system uses laser sintering to create the basic part with dimensional accuracy which varies according to the geometric complexity of the component. Electro-discharge and high-speed machining are then used as finishing operations.

Layered manufacturing allows extensive control over the internal structure of the component to ensure its strength. The laser-sintered tool can then have its surface eroded to create a texture, for a particular surface roughness. High speed machining can also be used for surface finishing purposes, for example, to provide a mirror finish.

Post-process surface hardening in a high carbon content furnace atmosphere further strengthens the outside of the tool if necessary.

Demand for rapid tooling stems mainly from companies wanting a simple way to test the market demand for a product or to tool up quickly to produce small batches. With the constant stream of new and improved products in the marketplace tooling no longer has to achieve a long, high output production life.

Cardiff MEC operations director Dr Stefan Dimov said: ‘The production of specialist tooling is the next stage in the shift to rapid manufacturing. The pre-production tooling we can produce is similar in cost to conventionally manufactured tooling, but companies will see a 50% reduction in lead times for tooling supply.’

The potential applications for rapid hybrid tooling are wide. The market for development of tooling for manufacturers in Europe is estimated at about e48bn (£27.7bn) a year. This includes pre-production tools for rubber moulding and pressure die-casting, inserts for replacing worn tool parts, and the production of prototype automotive components, with production runs in the hundreds.

On the web at www.mec.cf.ac.uk