Sustainable Castings are all about Money

At the moment, sustainability is nice to have. But often, it is just colouring some slides in the company presentation green. CBAM, which will start in 2026, will put a price on carbon emissions. The root cause of carbon emissions, the energy used, has become quite expensive in Europe. So, focusing on sustainability is a good business opportunity because the saved energy costs are a 1:1 profit on your balance sheet.

Considering our castings, there are two drivers for the carbon footprint: process and design. By using Rheocasting, you can save on carbon emissions on both ends.

For the process-driven emissions, you have to use low-silicon alloys. You can save between 0.5 and 0.9 kg CO2 per kg Al by avoiding silicon additions alone. The holding furnace doesn’t need to be as hot as liquid HPDC. The produced slurry is also at a lower temperature in comparison to the liquid melt. For an AlSi7Mg, it is around 610°C. The lower temperature doesn’t wear out the tool as quickly. As a result, 60–100% longer tool lifetimes are the norm.

Now, look at the second driver, the design-driven emissions. When adapting a part for Rheocasting, the first thing that has to be redone is the gating system. The projected area can be massively reduced by utilising the long flow length. Therefore, smaller machines are usable. About 20 to 30% size reduction is always possible. The smaller DCMs consume less energy in comparison to their bigger counterparts. With the laminar fill, porosity in the casting isn’t an issue anymore. This behaviour reduces the rejection rate. In addition, welding operations become more secure to implement, even for different material combinations. Let´s return to the alloys; while in the design phase, switching to low-silicon, high-strength alloys allows for weight reductions by using thinner wall thicknesses.

When working on sustainability, the work starts even before the first drawing of the part is done. Rheocasting enables you to be even more sustainable and profitable. Why don’t you book a Rheocasting Workshop to determine the best way to start producing sustainable castings.