Aluminum casting & mold design services

The automotive industry is currently in a once-in-a-century period of great transformation. Reducing environmental impact not only during driving (Tank to Wheel) via electrification (EVs) but also across the entire lifecycle from manufacturing to disposal (Well to Wheel / LCA) has become a top management priority. The key to this is “aluminum.” While demand for aluminum is surging as a lightweight material to extend EV cruising range, new smelting (production of virgin material) consumes vast amounts of electricity. Therefore, we have entered an era where the utilization of “recycled materials,” which can dramatically reduce CO2 emissions, determines the competitiveness of the entire supply chain. In this article, we will unravel specific recycling examples from leading companies such as Nissan Motor, Audi, and Novelis, while explaining the technical and structural challenges in shifting from the currently mainstream “cascade recycling” to the ideal form of “horizontal recycling (Car to Car).”

With the shift to EVs, an increase in vehicle weight due to onboard batteries is unavoidable. To offset this, the amount of aluminum used increases year by year. However, producing new aluminum ingots from bauxite requires approximately 20 times more energy compared to producing recycled materials. In other words, if too much virgin material is used for lightweighting, a “dilemma” arises where CO2 emissions during manufacturing actually increase. The only means to solve this is the maximum utilization of recycled materials.

Currently, the aluminum recovery rate in Japanese automobile recycling boasts an extremely high level of over 90%. However, the reality is that this is centered on “cascade recycling.” This is a downcycling mechanism where high-quality scrap such as body materials (wrought materials) is reused as “cast materials” such as engine blocks, which have a higher tolerance for impurities. However, as the shift to EVs progresses, the production number of engines will decrease, and the demand for cast materials will taper off. Therefore, the establishment of “horizontal recycling (Car to Car),” which revives body scrap as body material again, has become an urgent imperative.

Nissan Motor has introduced “closed-loop recycling” ahead of other companies toward realizing carbon neutrality across the entire supply chain. Specifically, collaborating with Kobe Steel and UACJ, they have built a cycle to separate and collect aluminum scraps generated during production and regenerate them into equivalent automotive aluminum sheets. In the new “Rogue” released in North America in 2021, this process was applied to panel parts such as hoods and doors, achieving a significant reduction in CO2 emissions. Furthermore, from 2023 onwards, they are expanding the adoption of sheets using low-CO2 blast furnace steel materials and green aluminum raw materials in domestically produced vehicles as well, serving as an important stepping stone toward their 2050 carbon neutrality goal.

In Europe, Audi was quick to start the “Aluminum Closed Loop” project in 2017. This is a system where offcuts generated in the press process are returned to the supplier and reprocessed into aluminum sheets of the original quality. It is reported that this initiative avoided approximately 350,000 tons of CO2 emissions in the period from 2019 to 2020 alone. Audi has succeeded in minimizing the ratio of virgin material use while preventing material quality degradation, thereby enhancing its environmental value as a premium brand.

Novelis, the world’s largest aluminum rolling manufacturer, is strongly promoting the improvement of recycled material content in automotive aluminum sheets. The average recycled material content across all products in fiscal year 2023 reached 61%, and they have set a goal to raise it to 75% by 2030. The company has developed recycling alloys such as “Advanz™ s5754 RC,” highly sorted from automotive scrap, and supplies them to European manufacturers like Jaguar Land Rover. This is a good example of a supplier side actively innovating recycling technology to support the decarbonization strategies of OEMs (automakers).

Automotive bodies use different alloys: the 5000 series (Al-Mg system) which emphasizes formability, and the 6000 series (Al-Mg-Si system) which emphasizes strength and bake hardenability. When these are mixed as scrap, component adjustment becomes difficult. For example, if the 5000 series, which contains a lot of Mg (magnesium), is mixed into a melting furnace for the 6000 series, it deviates from the component specifications of the 6000 series, so a large amount of virgin material must be introduced to dilute it. This diminishes the environmental benefits of recycling. The practical application of advanced sorting technologies such as LIBS (Laser Induced Breakdown Spectroscopy) is urgently needed.

Scrap recovered from End-of-Life Vehicles (ELVs) tends to be contaminated with iron parts (Fe) such as bolts and nuts. If the iron content in aluminum increases, the material’s ductility and fracture toughness decrease significantly, making it unusable as high-quality body material. While cast materials can tolerate a certain degree of iron content, when aiming for horizontal recycling into wrought materials, the removal of iron becomes an extremely difficult challenge. Thorough separation at the dismantling stage and the sophistication of sorting processes in the solid state are required.

To realize “Car to Car,” it is necessary to digitally connect information not only in the “artery” (manufacturing and sales) but also in the “vein” (collection, dismantling, and resource recycling). A traceability system must be built where dismantlers can instantly grasp which alloy is used in which model and collect them by grade. Since many small and medium-sized businesses handle recycling in Japan and Asian regions including Vietnam, the hurdle for such standardization is by no means low.

Aluminum recycling in the automotive industry has changed its meaning from mere “waste disposal” to a “resource security strategy” that is a source of competitiveness. Advanced cases like Nissan and Novelis demonstrate that constructing a “closed loop” where suppliers and OEMs become one is the key to balancing quality, cost, and environmental value. On the other hand, the decrease in engine demand due to the shift to EVs is revealing the limits of traditional “cascade recycling (diversion to cast materials).” Moving forward, “horizontal recycling” technology to return wrought material to wrought material, and the advanced sorting and refining infrastructure to support it, are indispensable. We, Daiwa Aluminum Vietnam, manufacture and supply high-quality secondary alloys based in Vietnam. Amidst the changing global supply chain, we will continue to propose optimal solutions as a partner that balances cost reduction and carbon neutrality realization for our customers.