By Edgar Lange, Düsseldorf
The current competition of vehicle power train concepts for a CO2 and emission minimization was discussed end of May at Graz on the occasion of the 29th International Conference “Engine & Environment” of the Styrian company AVL. AVL is the worldwide biggest independent company for the development of power train systems with combustion engines. The subject electric engine vs. combustion engine was on the top of the agenda. According to AVL CEO Helmut List, the combustion engine does not belong to the “old iron” for a long time yet: “Modern combustion engine concepts lead to an increasingly lower pollutant emission and we can expect further technical progresses,” emphasized List before the Conference.
Grey cast iron in competition with aluminium
In this context, the new eco-friendly production technology ecoCasting of company Fritz Winter, Europe’s biggest independent iron foundry as well as supplier and partner for the international automotive, commercial vehicle and hydraulic industry, aroused great interest among the visitors at Graz. Iron castings of the classic Tier-1-supplier who directly supplies to the big players of the automotive industry, starting with A as Audi to Z as ZF-Friedrichshafen, can be found today in nearly everything that moves. EcoCasting is the new light-weight brand of Fritz Winter that shall contribute to the rethinking in the engine build. It is a new foundry process for iron castings that enables to pour for example light-weight passenger car cylinder crank cases representing a competitive alternative to aluminium cylinder blocks.
Iron foundry revolutionizes
„We love to make heavy things light“, this is the maxim of the iron foundry from the North of Hesse. But, iron castings and light-weight design – what sounds like a contrast at first sight, how does this work? The essential characteristic of the 4-cylinder crank case produced by means of the thin-wall procedure compared to conventional iron casting processes is the in-house developed pouring procedure without the use of moulding sand. The highlight: The extremely thin wall thickness achieved by this is only 2,5 mm and this with extremely low tolerances of only 0,5 mm. Another surprise is that the grey iron cylinder block can score with a cost advantage of 28 percent compared to a crank case produced by means of the aluminium pressure casting procedure (HPDC). In comparison with the die casting procedure, it is even still higher. Benchmark in this context is a 1,6 L 4-cylinder Otto engine.
For this, the Fritz Winter engineers have figured out quite a bit: a compact design, a shorter engine length with a reduced cylinder distance as well as an optimized main bearing wall and above all the special pouring procedure that is up to now unique worldwide for passenger car cast iron cylinder crank cases. „During the pouring process, the iron is liquid like water and runs into smallest voids whereas aluminium behaves rather like a tough mass“, explains Richard Pausch, Director Sales of company Fritz Winter, an approach for the delicate structure of the new block. A positive result is also the big dimensional accuracy. The maximum deviation of weight between the CAD model and the finished casting is below 100g. It is true that according to statements of the company they could also pour walls even thinner than 2 mm but there are limits due to the fact that a casting in the end needs to be in such a condition that a fettling and a shot-blasting operation are still possible. Even so, the weight difference compared to an aluminium engine is only 1,5 percent.
Aluminium was yesterday
Fritz Winter understands ecoCasting as their new branding for their light-weight product portfolio. „Eco“ means „economic“ as well as „ecological“, that means a sustainable product. For ecoCasting light-weight parts require considerably less resources already for their production than conventional castings or comparable aluminium components. Above all as the raw material iron scrap is a complete recycling product. Therefore, we consider ourselves as a „recycler from the very beginning“, Pausch proudly says and refers to the fact that the raw material grey iron consists 100% of steel scrap. What becomes an engine block or a brake disc, perhaps has been before a railway track or a bicycle. However, primary aluminium, a ton of which currently costs 1.900 US$, requires ten times more energy in the production than cast iron. „One of our slogans at the last Vienna Engine Symposium was therefore: ‚Aluminium was yesterday‘, which caused a couple of smirks", remembers Sebastian Hahn, Marketing Director of Fritz Winter Eisengießerei GmbH & Co. KG. In any case, the light-weight components currently have a great appeal among the automotive customers of the foundry: Around 800.000 ecoCasting cylinder crank cases have already been shipped. With this, the supplier wishes to offer a serious alternative to aluminium to the market and keep fit for the automotive light-weight future. Sales Director Pausch considers cast iron still as unbeatably cost-effective and with this future-proof. „The raw material iron is not dead for a long time yet“, Richard Pausch says confidently.
Checked: We talked to Richard Pausch, Director Sales of Fritz Winter Iron Foundry at Stadtallendorf.
How does the market receive your new thin-wall iron castings?
The demand is active. For the market currently requires lower wall thicknesses for a cylinder crank case for example due to reasons of weight reduction. No supplier will be able to avoid this fact in the future in order to be able to survive in the long run. EcoCasting is currently the most eco-friendly foundry process with which we are leading worldwide. However, we also know that no automotive customer will accept a supplier monopoly for thin-wall castings in the long run. This means that in this context we need to stay always on the ball and right in the front, as far as technology is concerned. With the competitive alternative to aluminium cylinder crank cases, Fritz Winter considers themselves on the way to a global supplier.
How is Fritz Winter positioned when the share of vehicles with combustion engines will decrease and the sold number of electric vehicles will increase?
Also in a future electromobile world we at Fritz Winter see a market for us and plenty of opportunities for new products in the area of thin-wall castings, for example for battery and E-engine housings and of course for brake discs of which we are already selling 20 million pieces per year. Therefore, also in this context, we count on a company success by means of cost efficiency and sustainability with cast iron light-weight concepts. Our new and innovative ecoCasting production procedure has convinced ourselves that much that we have invested more than 50 million Euro since the beginning of 2013 in the implementation of this process. The scope of investment for a thin-wall pouring line in total is even a bit lower than that for a conventional foundry bound to moulding boxes, among other things because the stockpiling of boxes and the sand preparation can be omitted.
Does the current discussion in the automotive light-weight construction that tends to solutions with aluminium components go into the right direction?
The automotive traffic is responsible for only ten percent of the global CO2-emissions. However, this is not always taken into account correspondingly in the social and political discussion. This refers also to the fact that vehicles equipped with aluminium crank cases have to be operated clearly longer than the average vehicle life time in order to compensate the CO2 balance in comparison to those vehicles equipped with ecoCasting cylinder crank cases. This means that the values over the complete life time are decisive and in this context cast iron has a clearly better performance with a CO2-emission of 1.783kg per each kg of produced material than a ton of primary aluminium produced in a global energy mix with approx. 6.174kg CO2. This should be taken more into account by the political decision-makers.
So, in the long run, you definitely see a future for your company for innovative cast iron light-weight products such as the engine block?
Definitely. However, a critical issue could be the personal know-how for this old-established technology. If in a few years no one will be really interested anymore in the further development of combustion engines, there would be no qualified engineers available anymore. And this would be a pity.Back to overview