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A D V A N C E D M A T E R I A L S & P R O C E S S E S | S E P T E M B E R 2 0 1 9 2 6 Mercedes-Benz soldmore than 1.1 million A-Class cars in its seven-year production run. to build the A2 without any other sup- pliers involved. To that end, ALS bought BDW, a casting company with prior ex- perience in thin structural castings. ALS also produced the extrusions, using its own 6014 alloy. The design demanded great di- mensional accuracyandmuchattention was focused on reducing variability. For the castings, that meant using forced air quench, and for the extrusions, they used a tailored spray quench that pro- vided different spray densities on dif- ferent areas of the section. Some of the extrusions required hydroforming to finesse their dimensional performance, with the long roof rails being the most important. Again, ALS was responsible for the hydroforming. To better sup- port Audi, ALS set up their plant in close proximity to Audi, delivering machined, formed, and/or welded assemblies to the A2 body shop. On the sheet front, ALS and Audi negotiated a recycling agreement, with materials, and new powertrains. Ford seized the opportunity to further de- velop its AIV technology and keep the core development team intact. By 1996, Bill Stuef and his team were working on a new AIV sedan based on a stretch ver- sion of Ford’s global CDW132 platform. The program was called P2000, P for PNGV and 2000 for the targeted gross weight including the internal combus- tion engine (ICE). The mid-size sedan was designed to support several pow- ertrains, from an exotic small displace- ment ICE to an electric hybrid and even a fully electric version powered by a fuel cell. The first build started in 1997 with the prototype presented to the press at the North American International Auto Show on January 11, 1998. COMPETITION AMONG ALUMINUM SUPPLIERS Meanwhile, in 1994 Alcan moved to secure a potential ABS footprint in Europe by acquiring and upgrading the cold mill and heat treat facilities in Nachterstedt, Germany. Alcan was enjoying small-scale successes with their AVT body structures: In Septem- ber 1996, Lotus unveiled the Elise, a lightweight minimalist sportscar, and in December, GM delivered the first EV1. Alcoa had beaten them both to the punch though, with Chrysler stag- ing the press release of the Plymouth Prowler on June 26. Alcoa built and operated a dedicated facility in North- wood, Ohio, to build the spaceframe for Chrysler, shipping partially finished bodies to the Conner Avenue Assem- bly Plant in Detroit. Alcoa’s new plant was similar to the one in Soest, Germa- ny, where the company had just started production of the front structure for the Mercedes-Benz A-Class. By the time of the Mercedes A-Class reveal at the Geneva Motor Show in 1996, Audi was working on its answer, based on an updated concept of the Audi Space Frame (ASF). Unlike the A8, which was essentially hand built at a maximum sustained rate of 80 cars per day, production plans for the new model (the A2) called for a build rate of 300 cars per day. The engineers includ- ed all the lessons learned from the A8: They simplified the design, aiming for more than 80% automation in the body shop and eliminating the expensive oven cure after the body shop. They lim- ited the number of bent extrusions to just six. The underbody structure was a simple ladder of high precision straight extrusions, with T-joints replacing the previous cast nodes. They replaced 30 meters of MIG seams with laser welds and nearly doubled the number of riv- ets. The new design placed a heavy emphasis on part integration and form- ability lessons learned from the A8. Further, the new design reduced the number of castings from 50 to 20, ex- trusions from 47 to 22, and stampings from 237 to 183 for a total of 225 parts instead of 334. One of the more impres- sive achievements was a steel-like, one- piece body side panel, eliminating a joint on the rear pillar (Fig. 1). The total body weight was 153 kg, a 43% weight savings versus a compa- rable steel body. The A2 was also more spacious than its across-town com- petitor, and by virtue of additional lightweighting actions, it weighed in at just 895 kg—a full 200 kg less than the Mercedes A-Class. Al- though Alusuisse (ALS) had only entered Audi’s supply base due to Alcoa’s lack of a European foot- print, the two companies had soon forged a tight relationship, andAudi was now ALS’s top priority custom- er. The two companies committed Fig. 1 — Exploded view of the Audi A2, showing the one-piece body side panel.