Hardly any other technological development has changed everyday lives more than the automobile. Mobility forms the basis of our modern lifestyle and economic activity – it is the factor with the greatest influence on how we live within a globalized world. The issues of climate protection, environmental friendliness and resource saving are the key driving force for technological development in the automotive industry. The increasing need for mobility – coupled with a shortage of resources and ever stricter requirements for environmental protection at the same time – poses one of the greatest challenges worldwide.
In today’s automotive industry the trend is towards ever more powerful engines with smaller engine displacement. It is the stated goal of downsizing to reduce fuel consumption while lowering the emission of pollutants at the same time. The design of these usually turbocharged engines results in higher exhaust temperatures, which entails greater requirements for the design of the components and the materials used. As a result, the service life of the engines depends on both the design as well as the materials used. Here VDM Metals has recourse to a wide variety of materials that fulfill the diverse requirements within different sections in the automobile. These include e.g. high temperatures, creep resistance, load alternation, corrosion resistance or wear resistance. Strip, sheet, wire and bars from VDM Metals are indispensable to many automotive components.
Developments over the past decades have made driving increasingly safe. Thus, seat belt tensioners and the installation of airbags has led to greater safety for the occupants in the potential event of an accident. Complex technology is also involved here. Rupture disks contribute to safety in airbag systems. Thanks to its definite mechanical properties at elevated temperatures, VDM® Alloy 625 prevents airbags from triggering inadvertently, for example in case of vehicle fires.
The turbocharger plays a central role in downsizing and hence reducing fuel consumption plus emission rates at a simultaneously high engine output. Especially high-quality materials are used for the turbocharger design, in order to ensure a long service life and reliable functioning by the component.
The heat shield
The heat shield separates the turbine area (hot) from the compressor area (cold) in the turbocharger. Heat-resistant alloys such as VDM® Alloy 800 H and VDM® Alloy 601 are used as materials for this. If the heat shield is to exhibit elastic properties additionally at high temperatures hardenable super alloys such as VDM® Alloy 718, VDM® Alloy C-263 or VDM® Alloy C-264 are used.
Hardenable super alloys such as VDM® Alloy 718 or VDM® Alloy C-263 are also used for the manufacture of turbocharger gaskets.
The exhaust catalytic system has the task of converting harmful exhaust constituents that result while the engine is operating into harmless gases. The catalytic system is located as close as possible to the manifold in order to reach its operating temperature and hence lower pollutant emissions also in the engine’s start phase. This calls for highly heat-resistant materials so as to ensure fault-free functioning over a long service life.
The inside of a catalytic converter must have the maximum possible surface area for the catalyst to be used in many cells and channels for effective cleaning of the exhaust gases. Besides ceramic catalyst carriers, metallic carriers are also used. Compared with ceramic, thin metallic foil offer many advantages in the start phase of the catalytic system owing to their low thermal capacity, thereby allowing the catalytic system to reach its operating temperature faster.
With its VDM® Aluchrom Y Hf und VDM® Aluchrom 4 18 Y Hf, VDM Metals, provides materials that can be manufactured as wafer-thin foils with a thickness of 0.03 mm (0.001 in).
Hardenable, high-temperature resistant alloys such as VDM® Alloy 80 A and VDM® Alloy 751 are used for outlets valves subject to high loads.
When it comes to commercial vehicles and passenger car diesel engines, VDM Metals has developed the alloy VDM Ally 788 A® specially for the requirements predominant here. Besides tremendous mechanical properties, this material exhibits a better wear resistance in comparison to VDM® Alloy 80 A. Thanks to the new material, there is no need of hardfacing the valves.
The fuel systems in modern engines are designed for as low fuel consumption as possible combined with improved emission values. As an injector for instance, the Piezo injection nozzle ensures optimal injection for lower fuel consumption. As the material has specified expansion properties, VDM® Alloy 36 is used for the housing construction of the ceramic Piezo stick.
Spark plugs play an important role in gasoline engines, as they are responsible for ignition of the fuel-air mixture. In this way, they influence not only the engine’s performance and smooth running, but also the pollutant emission and fuel consumption. Besides a good high-temperature corrosion resistance, good spark erosion resistance is also called for.
Nearly all spark plug manufacturers use materials made by VDM Metals for their electrodes. These are available as round and flat wires e.g. made from VDM® NiCr2Mn or from VDM® Alloy 600 L. So-called long life plugs prolong the service intervals. They are alloyed with elements such as yttrium and hafnium.
Glow plugs are required in diesel engines in order to ensure that the engine starts reliably and runs quietly with low emissions in the warm-up phase. Strips of such materials as VDM® Alloy 601 and VDM Alloy 602 CA® have proven effective for manufacturing of glow plugs.