Sustainability gets set at the Drawing Board

CBAM is often seen as a customs, reporting, or procurement issue. That is understandable, as the cost appears in sourcing decisions, supplier quotations, and customer pricing. But that is not where the problem begins. By the time purchasing starts, comparing offers, much of the future CBAM exposure has already been fixed. It was defined when the part was designed, the alloy was chosen, and the process window was defined.

CBAM does not charge a company based on how hard its buyers negotiate. It charges for the embedded emissions of the imported product. In aluminium castings, the largest share of those emissions comes from the alloy itself, not the casting machine. So, the alloy strategy is no longer just a metallurgical question. Under CBAM, it becomes a cost question from the very beginning.

Purchasing sees the Bill, but the Designers create it!

The uncomfortable truth for many organizations is that purchasing usually enters the story too late. It can negotiate with suppliers, request better documentation, and try to limit commercial damage. What it cannot do is undo a design decision that already locked the part into a high-emission production route.

That makes the real decision-maker “the guy who owns the drawing,” because the foundry has very little influence if the demand is not created upstream. In other words, the engineering team does not just define the part. They define the commercial options of the part. If the drawing requires a primary alloy, the foundry and purchasing department can still optimize around the edges, but the component’s main carbon footprint has already set.

Why Primary Alloys becomes a CBAM Risk

For years, specifying primary aluminium often looked like the safe option. It reduced material uncertainty and simplified technical discussions. Under CBAM, however, that same decision can become expensive. The reason is straightforward. Primary aluminium typically has a much higher carbon footprint than well-managed secondary routes, and CBAM translates that footprint into direct financial exposure. Even the best primary alloys sit around 4 tons of CO2 per ton Al, while global averages are more like 16 tons per ton Al. In the coming years, the CBAM factor shrinks, so that the deductible benchmark effect shrinks, which makes the payable share of emissions rise over time.

That is why “primary by default” is becoming a strategic weakness. A part may still function perfectly, and a buyer may still secure an acceptable unit price, but the hidden carbon cost remains embedded in the material choice.

Secondary Aluminium is not a Quality Compromise by Definition

One of the biggest barriers to lower-carbon design is still cultural. Many engineers and buyers continue to treat secondary aluminium as if it were automatically inferior. Today, scrap-based aluminium can achieve quality levels close to those of primary alloys, but only when the recycling process is properly managed. The quality of the secondary alloys depends on the cleanliness of the scrap input, sound furnace practice, proper alloying, temperature control, degassing, and filtering. The limitation is therefore not the word “secondary.” The limitation is whether the system around it has been designed to handle it properly.

That distinction matters enormously. If secondary alloys are treated as a serious engineering route that requires proper sorting, segregation, and metallurgical discipline, it becomes a very different proposition. More advanced sorting technologies, including spectrum-based segregation by alloy family, can help move beyond mixed scrap streams toward cleaner, more predictable material input. Better scrap preparation means higher yield, better control, and greater freedom to design with lower-carbon emissions.

Rheocasting turns Sustainability into Design Freedom

In the sustainability discussion under CBAM, Rheocasting becomes far more than a production process. Its strategic value is that it gives designers and foundries a wider alloy window than conventional liquid die casting. Rheocasting enables systems to be designed around secondary alloys to gain a sustainability advantage over competing processes. And that is the key step. CBAM costs can only be reduced at the design stage if the production process itself creates room for lower-carbon alloy choices.

Rheocasting also matters because it is not only about carbon. It helps align sustainability with performance. It also significantly reduces defect levels within the casting, and application windows become accessible due to the laminar flow behaviour. That combination is important. Engineers rarely adopt a new route just because it is greener. They adopt it when it solves several problems at once. Rheocasting is compelling precisely because it can connect lower embedded emissions with technical functionality, design flexibility, and, in the right case, a more attractive total cost position.

Conclusion

CBAM is often presented as a tax on imports. In practice, it is also a test of design maturity. Companies that continue to specify primary aluminium by default will discover that purchasing has very little room left once the quotation phase begins. Companies that build in alloy flexibility from the start, and that use Rheocasting to make sustainable secondary routes viable, will be in a much stronger position.

The decisive move is therefore not at the border. It happens much earlier. It happens when the drawing is created. That is where the future CBAM cost of a casting is won or lost.

The Rheocasting Materclass teaches you how to utilize Rheocasting for lower carbon emissions and higher performance castings. Pre-register for the next public Masterclass or schedule a call to organize a private Masterclass for your organisation.