The Material - The Basis
Materials form the basis for our vehicles and production processes. However, their importance extends even further. With their haptic and visual properties, they convey the product experience and quality understanding of the Volkswagen Group.
We work on the best possible material for each customer requirement, Group segment, vehicle design and component. The functions of materials optimize component performance, design, convenience and customer safety.
We are forging ahead with a change of perspective towards entirely new materials. We focus not only on classical parameters such as strength and deformation but also on the entire spectrum of mechanical, chemical and electrical properties. For the optimization of materials, we pursue a holistic approach covering material utilization and the production process. Thanks to simulation, we gain an even deeper understanding of material behavior right down to the level of the atom.
We put this know-how to use both in the development of new materials and in flexible and efficient production processes. Virtual technologies improve the economic viability of these processes. Our joining technologies open up entirely new possibilities for the Group with respect to the material mix and shaping processes. The results are tailor-made, optimum materials and material combinations that meet the highest requirements as regards sustainability, cost effectiveness, safety and appearance.
We consider the materials used within the system, cooperate with developers, production and assembly experts and are a reliable, inspiring partner for research institutes and suppliers.
Adhesion Study Using a Range of Material Surfaces
No matter what the type of contact surface, be it between an adhesive and a metal body, between a functional layer and the cylinder contact surface, or between the cover coat and a plastic component, one requirement always applies: the two surfaces have to adhere to one another permanently.
The adhesion conditions are just as diverse if the component is coated. This is on account of the high number of combinations of coatings and components which are available. In order to test the suitability of an adhesive or a coated component, the adhesion between the coating and the base material has to be thoroughly examined.
Our experts in the Group Research division use a computer-aided approach to testing contact surfaces. This enables them to simulate adhesive strength, particularly for results in the nanometre and micrometre range. Using the results from the adhesive strength calculations, they are able to draw conclusions regarding adhesion between various combinations of materials.
Prototypes are also measured and analysed in our labs. Our team apply a wide array of methods. For example, a contact angle measurement device can be used to determine the surface energy for the individual material surfaces, a scanning electron microscope (SEM) and an energy-dispersive X-ray spectroscopy (EDX) can be used to map the structure (all the way down to nanometres) and the atomic composition, while a nanoidenter can be used to define the adhesive strength.
Understanding exactly how the coating and the base material interact with one another plays an important role in helping us to find new combinations of materials for vehicles and light-weight construction.
Innovative Material Solutions for Thermal Management
CO2 requirements and electric mobility call for innovative material solutions to help manage the thermal conditions in the vehicle interior. Innovative materials will help to make sure that the passenger compartment stays at a comfortable temperature throughout the year, without affecting the vehicle's range.
Instead of using active air conditioning components, we will be focusing on passive solutions based on new materials and construction methods. This may involve using insulated materials, glass surfaces with specific functions (IR reflection, active and passive dimming, coatings with a low thermal transfer), or even IR-reflective paints.
Calculating thermo-mechanical indicators for potential body and interior materials in order to simulate thermal conditions inside the vehicle forms an important basis for our work. A range of measurement methods are used to analyse both production materials and innovative new materials. Stationary and non-stationary measurement methods are particularly important when it comes to calculating thermal conductivity.
As well as finding innovative solutions for the interior, we are also looking for new ways to improve thermal conditions in the combustion engine and in the battery. Our goal is to find the perfect material for optimum thermal management for a range of different applications.
Two-Stage Shearing Process to Reduce Edge Crack Sensitivity
The edge crack sensitivity of high-strength steels poses a major challenge in cold forming processes for complex components. By applying an innovative shearing process, engineers have been able to eliminate all edge cracks and keep the amount of damage to the surface of shaped sheared edges to a minimum.
When forming the collar for steel plates, a range of experiments into the two-stage manufacturing process meant that the expansion ratio could be increased by up to 100 percent thanks to the high quality of the shearing surface. This process was developed in a joint project between the KEFW/M department at Group Research, the Institute of Metal Forming and Casting at the Technische Universität München (Munich University of Applied Sciences), and Volkswagen Component Production in Braunschweig.
New Methods for Simulating Hot-Forming Processes for Ultra-High-Strength Steels
One of the biggest challenges facing civilisation in the 21st century is man-made climate change and the resulting effect of global warming. Leading politicians and scientists share the belief that global CO2 emissions have to be halved by the year 2050 in order to prevent the planet’s average temperature from increasing by more than 2°C. The general rule of thumb for the world of passenger car engineering is that every 100 kg of weight saved will reduce CO2 levels by 850 g. Making up 40% of the vehicle’s total weight, the body holds a great deal of potential when it comes to finding ways to save weight.
An innovative way to reduce the weight of the vehicle body is to substitute less robust materials with ultra-high-strength steels. While maintaining the same level of performance, the thinner walls mean that the components can be up to 20% lighter. Due to the production methods required, ultra-high-strength body parts made from steel sheets are normally manufactured using a hot forming process. During this process, the sheets are shaped at high temperatures and also hardened at the same time. These processes are highly complex and therefore require our production engineers to use simulation technology throughout the design process. The current standard approach to method planning involves using thermo-mechanical simulation models to safeguard against material failures in the forming stage. Our Materials and Production Methods department is currently working hard on research into material models in order to increase the precision of structural models and therefore improve results for the associated attribute-based forecasts. By linking all parts of metallurgical material models and thermo-mechanical material models, we are able to make more precise predictions regarding the attributes of complex components produced using hot forming processes.
Volkswagen Group Research is responsible for studying the feasibility of this matter and not its use as standard equipment. The use in vehicle production is not currently planned at this time.