The BMW Hydrogen 7 car has been built in a limited series (around 100) in Europe based on the BMW 7 Series and they are currently being tested in different parts of the world – including by NASA scientists.
BMW states that the new car is equipped with a 260hp 12 cylinder IC engine capable of switching from using either hydrogen or petrol fuel at the switch of a button on the steering wheel. When driving in hydrogen mode, engine emissions are virtually nothing but water vapour.
The car features a high-tech vacuum super-insulated hydrogen tank in which liquid hydrogen can be stored for long periods if kept under pressure and at the extremely low temperature of -253ºC. Gaseous hydrogen is said to have the highest energy content of any common fuel by weight, about 3 times more than petrol. In a liquid state at -253ºC hydrogen also has excellent energy content by volume.
A research programme is currently underway in Austria called HYDRO-PIM to develop potential applications for complex shape metal injection moulded stainless steel components for use at the extreme low temperatures. Potential applications can be found in the hydrogen storage tank of the BMW Hydrogen 7 and also in the fuel supply to the engine.
The research has focused on testing DIN 1.4404 (316L stainless steel) materials produced by the metal injection molding process, and the results obtained so far were presented at the Euro PM2007 Congress in Toulouse and are published in the issue December 2007 issue of Powder Injection Moulding International.
ARC Seibersdorf Research GmbH, a research partner in the project, reported the surprising finding that MIM 316L stainless showed an almost threefold increase in tensile strength and with only modest loss of ductility at -253ºC compared with room temperature properties, and that they would be excellent candidate materials for components used in the BMW Hydrogen 7 car. Other Austrian partners in the project include Magna Steyr, Ernst Wittner GmbH and Westcam Project Management GmbH.