Can you give an example?
Fabian Niklas: A Japanese Tier-1 supplier that operates its own foundry looked at this issue and concluded that with rheocasting it could produce CO₂ compressors that are about three times more efficient. The components are helium-tight at 180 bar without any impregnation. In addition, you can move from a single-cavity to a dual-cavity design and achieve significant efficiency gains. But in Europe, hardly any Tier-1 currently dares to take such a decisive step.
And this is not only about willingness, but also about the consequences. In the Japanese example they had used the same standardised gating system for more than 25 years across all moulds. After two simulations it was clear that this design would not work for rheocasting. At that point you need to decide on a completely new gating concept, a new mould design and new process windows. Those are far-reaching decisions that must be taken if rheocasting is to be profitable in series production.
Do you see regional differences here?
Fabian Niklas: Yes, very clearly. Such decisions are more often taken in North America, China and India, partly because competitive pressure is extremely high and partly because there is a stronger entrepreneurial mindset. These Companies are using technology to their advantage. You could also see this at EUROGUSS. At the Casting-Campus booth, about 40 per cent of visitors seemed to come from India, and they asked very concrete questions about how to implement rheocasting properly. Visitors from European foundries were in the minority.
Why do you think Europe is more hesitant?
Fabian Niklas: The reasons are quite clear. Europe depends heavily on automotive volumes, and that sector is currently under enormous pressure. Margins have been declining for years, volumes are uncertain, and many foundry locations are expensive while often producing relatively standard components. A shock tower, for instance, is not a component that necessarily requires a high-end manufacturing location in Western Europe. It can be produced elsewhere with the same quality. In that context, “more automation” alone does not solve the problem if volumes are falling.
The common attitude is often: “This is not the first crisis. Let’s conserve cash and wait – we will get through it.” But this time the change is structural. European vehicles have become too expensive for many buyers, and competition from China is enormous. In such an environment it is very dangerous to postpone technology investments.
And something else I often see: companies “test” rheocasting by taking an old die casting mould and running it on some trial machine. They produce a few shots, quality is predictably poor because the mould was never designed for the process, and then they say: “See, we are not missing anything.” But that is not a fair test of the technology.
Which of the well-known advantages of rheocasting attracts the most interest from companies?
Fabian Niklas: There is not just one application for rheocasting. It is more like a bouquet of applications where it makes sense, and many fail because they start from the wrong point.
Many companies come from the automotive sector and say: “Here is a die-cast component – let’s convert it to rheocasting.” That usually fails, because the component already works as a die-cast part. Take a typical shock tower: it is designed for an alloy such as AlSi10. If I want to produce it by rheocasting, I may have to switch to AlSi7. That means new material specifications, new approvals – everything starts again from scratch. In the end, you get higher strength and elongation, but the application may not actually need those properties. In such cases, “rheocasting as a substitute” is simply not the right approach.
