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BIA-Brukerstyrt innovasjonsarena

Complex EXtruded Aluminium Profiles for BEV Battery ProtECTion System

Alternative title: Komplekse aluminium profiler for beskyttelse av batterier i elektriske biler

Awarded: NOK 14.0 mill.

Batteries in electrical vehicles (EV) need to be protected in case of a car crash. The battery is fairly well protected from a front or rear crash situation, being placed in the middle of the car, so focus is mainly on side crash. Aluminium profiles are well suited for side crash protection, absorbing much energy pr. kg aluminium. The draw-back is related to cost, aluminium being more costly than most steel solutions, but so far EV's on the market use a substantial amount of aluminium profiles. The car manufacturer use somewhat different solution for the battery protection. Most common is using a tray with a frame consisting of aluminium profiles, the longitudinal profiles often being large and complex. In addition there is a beam (sill) under the doors, that also can be a large and complex (means a profile with several chambers) aluminium profile. To ensure a continued large scale use of aluminium (high volume models), more cost effective solutions are needed. Large profiles with several inside chambers suffers from a high extrusion cost, especially when produced in a high strength alloy. High strength is desired in order to reduce weight, but not at an unacceptable loss of ductility (the profile should not fragment or cut in two pieces). In the project we will physically test profiles, do numerical simulations and evaluate effects of design and choice of alloy composition. We will also investigate the possibilities of doing mechanical calibration (to get the profile geometry 100% correct) and then avoid costly machining typically done today. Benteler is today producing battery trays in France, Germany and China for several EV models, while Benteler in Norway (Raufoss) so far has only touched this area (prototype production of profiles and trays). The aim is to establish business in this huge market in the project period. The project started 01.02.2021 and has initially focused on a booked order on the sill for Volvo XC40 Electric, planned to increase from a first forecast of 40 000 cars to 155 000 cars/year. The 155 000 cars represent a net annual extruded volume of 2600tons, or ca.20% of the extrusion capacity of the biggest Benteler extrusion press. The work has followed two paths, i) Simulation of material flow in extrusion to optimize die design and extrudability and ii) Mechanical calibration of the profile in order to reduce machining. The latter process change is planned to take place early 2022.

This project addresses the rapidly growing market for battery tray protections systems for electric mobility and the BEV (Battery Electriv Vehicle) market. Battery trays, and battery protection systems, are predicted to be the new "backbone" of a car, integrating a multitude of functionality. Material properties and structural behavior of the products are crucial as well as productivity and competitiveness for the supplier value chain. Due to geometric constraints and crash requirements, the sections used are very complex, while still requiring the highest possible strength and crushability to remain competitively priced. This project aims at developing an aluminium alloy optimization scheme for extrudability, crash management, and design functionality of complex multi-chamber profiles seen more and more in such structures. Hydro, Benteler, NTNU and Sintef Manufacturing will co-create the required knowledge to fulfill the project objectives, and Hydro and Benteler will commercialize it through concrete customer projects. The battery casing/system contain close to 100kg aluminium per car, a big share of that is extruded profiles. Market estimates predict that this will generate a market in Europe for over 240 000 tons aluminium in 2025. Innovations from this research project for Benteler and Hydro is estimated to give an annually added value in the range of 250 MNOK – to be realized from 2023/24. EU set forward an ambitious target of reducing CO2 emissions from cars by 37.5% by 2030. This target will reshape the automotive industry, where electrification of vehicles is expected to drastically change the use of aluminium in cars. While the combustion engine disappears (consuming 42kg aluminium/car) new aluminium components will arrive.

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BIA-Brukerstyrt innovasjonsarena