Among the technologies that are discussed is one that is well known: the force applied in rolling aluminum plate is crucial to its fatigue resistance. Accordingly, the Zhenjiang mill has been equipped with what Aleris says is the most powerful rolling mill in the global industry, a Siemens VAI unit capable of applying a force of 6 meganewtons (1.35 million lb.) as it squeezes slabs into plates.
The Zhenjiang mill is not yet producing salable aerospace aluminum. It must first prove itself with lower-grade aluminum for other industries and work on reaching the AS9100 certification standard necessary to supply aerospace. That should be achieved after a year of operation. The plant will make 7050, 7075 and 2024 aluminum—conventional aerospace grades, not the more recent types called advanced aluminums, nor the alloys aluminum-lithium and aluminum-magnesium-scandium. Aleris has for years been working intensively on the latter alloy in Germany, and more recently on aluminum-lithium, a favored product of rival Alcoa. The third big supplier to aerospace, Constellium, opened an aluminum-lithium foundry at Issoire, France, in March. Aleris says it will not supply military customers from Zhenjiang.
The advantages of producing in Asia are simply cheaper and quicker deliveries to Asian customers, says Petry. The cost of raw materials is little affected, because the expensive 99.94% pure raw aluminum needed for aerospace alloy is available locally. If the market is big enough, the Zhenjiang plant's whole capacity of 35,000 tons a year can be devoted to aerospace product. Aleris estimates Asian demand for aerospace aluminum at 45,000 tons a year. Japanese producers such as Furukawa-Sky are focused mainly on their domestic market, which they do not fully satisfy; Japanese aerospace manufacturers are major aluminum importers.
Zhenjiang should be producing at its current designed capacity by year-end. The factory building is far from full, because Aleris has provided for expansion. Petry specifically mentions the possibility of a bigger stretcher, an enormous piece of equipment that literally stretches plate from the rolling mill to greater lengths and thinner thicknesses for such purposes as wing skins. The current stretcher at Zhenjiang can pull plates to a length of 24 meters (79 ft.) and is intended for narrowbody aircraft, such as the C919.
Of the more than 300 people who work at the plant, 150 were trained in Germany.
Industry officials say two Chinese aluminum suppliers, Nanning Nannan Aluminum and China Southwest, are working toward achieving production quality that would satisfy international aerospace standards. If and when they do, the global aerospace industry's material supply will again tilt toward China.