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Commercialization of a full carbon wheel manufactured with an automated high-volume process for the automotive market

Periodic Reporting for period 1 - CARIM (Commercialization of a full carbon wheel manufactured with an automated high-volume process for the automotive market)

Reporting period: 2016-01-01 to 2016-12-31

• What is the problem/issue being addressed?

Car weight has increased continuously in recent years. Despite the development of more efficient engines, the higher fuel consumption due to weight, and consequently higher CO2 emissions, have required intervention by the EC to set a path for emission reduction in the coming years.

Research into lightweight components, materials and the related processes, has led to the substitution of standard steel. Typically, steel is first substituted by aluminum, but automakers are looking more and more at CFRP technologies. This will also be important for next-generation hybrid or electric vehicles.

Reducing unsprung mass in the automobile, especially in the wheel, leads to lower inertia in acceleration, braking and better handling behavior. In the CARIM project, the first production process for a high volume automotive wheel made exclusively of carbon-fiber-reinforced plastic (CFRP) addresses the issues mentioned above. An automated preforming and high-pressure resin transfer molding (HP-RTM) process chain is being designed, developed and validated to provide an economic production concept for CFRP wheels.

• Why is it important for society?

This market opportunity will be the start of further private investment and development in a European key technology (carbon composites), and opens a new sector for the automotive industry.

CARIM will bring strategic benefits to Europe by boosting the wheel production industry in the EU, which is currently spread globally with a negative outlook for production in Europe. Once the technology developed in CARIM is available on the market, production is expected to focus increasingly in Europe because the carbon composite raw material transformation process is historically well established in this continent. Increasing the market shares of European wheel producers in the high-tech section will create new jobs, and ongoing developments and improvements will ensure the use of CFRP wheels in high-volume applications.

• What are the overall objectives?

CFRP will allow wheels that are 30% lighter than state-of-the-art forged Al-wheels, and 50% lighter than conventional cast Al-wheels. The automated production process will ensure economic advantages over the existing production technology. Following a five year plan, the production capacity at RiBa is forecasted to be 62.000 wheels per year by the end of 2020. The market implementation of the carbon wheel will occur one year after the project ends.

The initial target market is the premium sport cars segment and next-generation electrical vehicles. The possibility to scale up the production volume will furthermore enable technology transfer to wider markets (sports car segment, electric and hybrid engine vehicles). This corresponds closely to the innovation strategy of the partners, who are experts along the CFRP value chain. They will all gain specific know-how in medium volume carbon composite applications, and can benefit from the transfer of this technology to new application fields. The industrial partners will also have the opportunity to increase their turnover and staff.
The wheel design was defined and optimized for composite materials. FEM simulation tools were used to define the fiber orientations and laminate thicknesses of the wheel. The mechanical properties obtained by the design and simulation activities met the requirements for relevant tests.

The series production concept was defined by the project partners for the preforming as well as for the high-pressure injection process. The HP-RTM infiltration mold was designed according to the requirements of the preform, the injection strategy and the wheel design. After successful testing and validation, the wheel design was verified in a prototyping phase. The results showed the feasibility of the developed manufacturing strategy, also in terms of automation.

Several materials and their combinations were tested on specimen level and used for the structural design of the wheel. Relevant characterization methods were used to obtain physical and mechanical material properties in structural, fatigue and aged conditions. All data from the characterization activities was rated for the different materials to select suitable combinations for the automated wheel production.

The preforming molds have been designed and the selected manufacturing concept was proven on a laboratory scale. The molds are ready to be integrated into the process chain for the automated manufacturing of the carbon wheel prototyping phase in 2017. The HP-RTM mold will be a complex and automated manufacturing cell designed for industrial production for use with HP-RTM production equipment.

The homologation phase for the carbon wheel was intensely discussed and the test plan was defined.

The partners have disseminated the CARIM project at various trade fairs and contributed also to scientific conferences to spread the project activities to a wide audience. Another core element of the project work was the creation of a plan for the dissemination and exploitation of the CARIM results, including activities in the upcoming project phase and beyond.

An IEB was established which currently has one member.
Forged Al is the state of the art technology currently used to reduce the wheel weight. Forged Mg is not considered competitive, as it is associated with high raw material costs, difficulty in milling/working and poor ageing corrosion behavior.

According to a survey on a world-leading wheel supplier, forged Al has a market share of 60-70% of the sports cars segment (the remaining 30% to 40% share belonging to the heavier cast Al), and it has been confirmed that OEMs are now starting to ask for CFRP wheels.

Various concepts for CFRP wheels have already been developed but there is still a lack of available automated high-volume production technology for such products. In the CARIM project the development of this production technology is the main goal. Within the first project year the wheel and the necessary processes were analyzed and the production strategy was defined with respect to the feasibility of automation. An innovative concept which is beyond the current state of the art for available HP-RTM production technology is now available and will be implemented for the HP-RTM prototype manufacturing.

The sports and the aftermarket segments’ potential of 220,000 vehicles per year is a niche compared to the overall potential sales market, but the success on these markets will promote the introduction of the technology into wider mass volume segments. The production technology developed in the project CARIM aims to increase the European market share for high-end wheel products in the first step and has already created new jobs within the project consortium for the development activities. During the production implementation jobs will also be created to realize the goal of a production capacity of 62,000 wheels per year by the end of 2020, depending on the number of wheels demanded by the market until then.

A further implication of the project is its environmental impact. Due to the unique features of carbon wheels (reduced weight of the unsprung mass leads to lower emissions of the car) the technology will support the car makers’ efforts to meet CO2 targets, for fuel driven cars and also for the energy use of the increasing electric car fleet in Europe.
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