1st ICAI 2020

International Conference on Automotive Industry 2020

Mladá Boleslav, Czech Republic

through major industrial technologies. Especially problematic is formability at normal temperature, where low ductility of magnesium is particularly problematic. High- temperature forming is therefore required, which means greater energy requirements and hence cost of part production. In spite of these aspects, magnesium alloys are nowadays used in the manufacture of car body interior parts as reinforcements, or larger body parts such as the roof or bonnet. So far, however, this is not a widespread application, but the first applications of this kind. Another situation is in the use of magnesium alloy for the production of castings. Magnesium has good castability and by using other alloys such as Al, Zn, Mn its final properties can be optimized. It is possible to use essentially all foundry technologies. The biggest application is found in die casting and production of thin-walled castings. Production with this technology is fast and efficient and the production cycle is short. On the other side the risk of casting porosity and the need of elimination of free oxygen during the process should be taken into account. It is possible to use a protective atmosphere or vacuum. Thin-walled castings of complex shapes can be produced by this technology. Examples include the dashboard frame, body reinforcements, chassis parts, valve covers, seat structural parts, steering wheel frames, pedal bodies and other applications. Die-casting also produces larger parts of larger thicknesses, such as gearbox covers. Gravity casting is mainly used for ingot molds. In case of using sand molds, the moisture of the molding composition is problematic due to the reactivity of magnesium with oxygen. The general problem compared to die casting is the risk of not full running of melt into the mold. 3.1 Technical, economic and ecological aspects of using magnesium alloys The main aspects of the use and production of magnesium alloy parts include the technical-production, economic and environmental aspects. These aspects are very important and allow a closer look at the use of magnesium alloys. The production- technical point of view includes the level of difficulty of material processing by the given technology, production efficiency and quality aspects. Technical aspects are also related to economic aspects. That is, at what cost the product is produced and what is the energy intensity and efficiency of production. The ecological aspect is also related to the technical aspect. The main concern is the influence on the environment during the entire cycle of material use, from its processing to disposal. The level of production of pollutants and greenhouse gases accompanying this cycle. The selected aspects for the comparison magnesium and aluminum are given in Table 3. It is clear from the table that the price of magnesium in the markets is higher than the price of aluminum. The production of raw metal is energy intensive for both metals and produces a large amount of emissions and other pollutants. Therefore, the environmental influence of the production and processing of these metals can be considered as relatively high. The processing and production of parts and components is also energy intensive. In the case of magnesium, it is also necessary to use protected atmosphere during casting, which further influence the environment. Another possibility is to use vacuum and vacuum furnaces and casting machines. However, these are significantly more expensive and the need for vacuum generation means higher energy

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