Aluminium Scrap in the EV Era: RecAL’s Solution for Sustainable Recycling

The European Commission has set an ambitious goal to ban combustion engines by 2035. While discussions continue, the phase-out of combustion engines remains a key priority for Europe’s green transition.

Translated to real life solutions, this means electric vehicles (EVs) will make their way as the primary form of transport for Europeans. This change will also mark a shift in the aluminium-market, both for virgin and recycled materials.

Indeed, EVs need aluminium with high conductivity (1xxx), for which there is currently no secondary market. Besides, the biggest shift will be in the aluminium recycling cycle itself. With the combustion-engines ban, the established “sink” for low-quality aluminium scrap based on the A226 alloy will disappear, leaving a large part of this waste stream without a final destination.

The above brings up two important questions in the aluminuim recycling industry: how to keep recycling as much aluminium as before (including lower-quality scrap) and how to best include the automotive industry in this cycle. The RecAL project is answering both of these issues.

To make sure the automotive industry, as represented by EVs, stays in the loop, RecAL is working on creating alternatives to pure 1xxx alloys that will keep the high electrical conductivity characteristics while making use of the broadly available 6xxx waste streams. 

As of today, 1xxx alloys are only produced by virgin precursors. Their high level of purity (at least 99% aluminium) makes these key materials hard to include in the secondary market, as any minor impurity can degrade critical properties. 

This results in a highly demanding recycling process, as any residue or alloy can affect the final properties of this class of materials. To solve this, expensive and energy costly technologies are required, leading to the usual downgrading of 1xxx alloys when recycled. Currently, the recycling costs outweigh the incentive for green solutions. However, increased demand for high-performance wires and heat exchangers, particularly for EV batteries, requires a solution including recycled aluminium in order to meet demands.

As a solution, RecAL is developing new alloys based on admixture of recycled 6xxx material with 1xxx alloys. These will show recycling rates larger than 60% and meet the needed requirements, such as softness and ductility and, most importantly, high electrical conductivity. This approach will create a new waste stream for 6xxx alloy scrap, significantly produced by the automotive industry itself with contributions from the construction industry.

Image: ©RTDS

Concerning the issue of diverting the current stream of A226 (AlSi₉Cu₃(Fe)) scraps to a new “sink” requires the creation of new alloys that can answer the current requests of the automotive industry. A new technology first developed by Tesla has now become widespread in the industry, namely: gigacasting. This process stays true to its name, using high pressure die-casting to produce large, integrated aluminium components.

Gigacasting brings several advantages, such as a reduced number of parts and subsequent cost reduction, weight reduction due to the use of aluminium, and enhanced flexibility in designing of parts.

On the other hand, challenges arise as well. These include issues in thermal management due to large structures cooling at different rates, resulting in warping and cracks, and possible material defects due to air entrapment, leading to possible porosity and instability of the structure. Besides, this procedure is currently very expensive and, hence, still in the process of broader adoption in the industry, though the gigacasting market is projected to grow at 45.5% CAGR, reaching $711 million by 2029.

Alloys used in this process as well as in more traditional casting processes need to balance castability, mechanical strength, and cost-efficiency. Balancing alloy content, such as the ratio of silicon, manganese, and magnesium, is crucial to achieve a final material with the right castability while maintaining conductivity requirements. A special attention to strength, ductility and heat treatment flexibility is required as well. These specific requirements pose a challenge to the current recycling industry, since the alloy composition for casting needs to strike the right balance. 

To answer the demand in this paradigm shift within the automotive industry, RecAL is designing a new alloy class that will make use of the lower-quality A226 scrap previously employed in the production of combustion engines. This new class will integrate all of the most common impurities, while still being suitable for all casting methods. With this enhanced impurity tolerance, this class will be able to absorb the A226 scraps freed by the ending of combustion engines production.

Image: ©RTDS

RecAL’s approach goes beyond the closed-loop way already used by some of the key players in the automotive sector. It allows for a wide and consistent use of different aluminium scrap, cutting costs deriving from, for example, sorting for high purity materials. Moreover, the Digital Hub developed by RecAL will help planning and monitoring the recycled aluminium value chain, linking buyers and sellers and improving trust in the recycled product, boosting its usage and enlarging aluminium circularity.

By adding flexibility to the materials needed for producing 1xxx alloys, RecAL is not only expanding the market for 6xxx scrap, but also providing a green alternative for production of EVs. With EV averaging 20 to 30% more in terms of aluminium needs when compared to traditional vehicle and the overall automotive aluminium demand expected to grow over 40% this decade due to EV adoption, RecAL is playing a central role assuring Europe’s independence from the import of bauxite ore for aluminium production by contributing to a real circular economy within the continent.

RecAL is actively finding answers to integrate sustainable aluminium solutions into the EV supply chain. Stay tuned for updates on our latest alloy innovations and real-world applications. Subscribe to our newsletter here.