Appendix C: Pechiney Aluminum, CRV

Site:               Pechiney Aluminum, CRV
                    BP 27, 38340 Voreppe
                    France

Date Visited:       April 2, 1996

WTEC Attendees:     D. Apelian (report author),
                    M.C. Flemings, P.H. Mikkola

Hosts:              Jean-Francois Wadier
                    William Loue
                    Jean Charbonnier

BACKGROUND

Pechiney, a large private corporation in France (formerly a major national corporation that was recently privatized) has corporate axes in the packaging industry and metal production -- magnesium, aluminum, and other refractory materials. Its annual sales are on the order of $8-9 billion/year. CRV is a major Pechiney laboratory located in Voreppe, a suburb of Grenoble. CRV is the major research center for all the Pechiney corporations including the packaging operations in North America. Over 400 professional and non-profession staff work at CRV, covering a very broad spectrum of research activities from artificial intelligence and process control to metal forming and polymer technologies. The annual budget for CRV is $50 million, and the research laboratory space at Voreppe is around 400,000 ft². The WTEC team visited the solidification and forming processes sector, which is under the direction of Dr. Wadier. Figure CRV.1 gives background on the organization of the solidification forming sector, which covers melting and casting, cast alloys and foundry, and metal forming. The assets of the organization are given in Figure CRV.2, which shows that the sector has a variety of facilities available for R&D purposes, covering everything from liquid metal to the end product.

CRV is a major player in establishing ties and collaborative efforts with various groups around the globe. As shown in Figure CRV.3, by 1994 CRV had 50 ongoing activities within public research universities and laboratories in France. In addition to the French liaisons, CRV has strong ties with centers outside France as well as outside Europe. CRV is also engaged in a variety of European projects such as the Eureka and the Brite-Euram projects in packaging as well as aeronautical and automotive transportation applications. It also has a major investment in educating the future leaders of CRV by supporting post-doctoral appointments at 20 universities around the world. These are students who, in lieu of military service, spend a year and a half at a research laboratory overseas obtaining training for future research positions back in France.

RESEARCH AND DEVELOPMENT

Pechiney's group in melting and solidification research is very strong in personnel, equipment and intellectual property. It also is uniquely positioned in that Pechiney is one of the few aluminum producers in the world that is in both the primary aluminum production business and secondary aluminum production. The company is very much involved in recycling and thus has developed a great deal of expertise and proprietary information in melting, removal of secondary phases (inclusions), degassing of molten aluminum, flexing, etc. Moreover, since the casting operation is integrated into a corporation with an end product such as packaging, the performance of the metal produced can be assessed in the marketplace. For example, the refining techniques used during casting and the resultant performance in the beverage can industry can be measured under one umbrella at Pechiney.

Fig. CRV.1. Organization of CRV.

Fig. CRV.2. CRV's assets.

Fig. CRV.3. CRV and the international scientific community (as of 1994).

Much effort is spent on semisolid processing, specifically on thixocasting. The R&D program is devoted to the production of thixotropic billets as well as to the development of the thixoforming processes. The product name of the thixotropic billets is ALTHIX; these are now being produced commercially on an industrial scale. Currently available products are A356 and A357 in 3" diameter billets. Larger diameters are also being developed. The corporate philosophy is that Pechiney will supply aluminum billets to independent companies and will provide technical assistance to its clients. The emphasis is to contribute to the development of thixocast parts, especially for the automotive industry. Potential applications for thixocast components are parts needing high compactness such as brake master cylinders, ABS components, and fuel rails as well as parts needing good mechanical properties such as engine supports, suspension parts, and wheels. A schematic diagram of the billet casting process used by Pechiney is shown in Figure CRV.4. It can be seen that the approach is to circulate the fragmented dendrites in the hot top of the continuous casting apparatus. The hot top, the inductors, and the water chamber needed to control the cooling rates and to fragment the dendrites through electromagnetic steering can be noted on the schematic diagram.

The solidification group at Pechiney has also devoted considerable effort to the lost foam process, and has developed a process technology for carrying out the solidification of evaporative pattern casting (EPC) under controlled atmosphere and under a pressure differential. The apparatus is quite substantial, and the group has a great deal of expertise in defect prevention and control of such defects during EPC. The laboratories and the cast shop facilities are most impressive, with state of the art equipment and very qualified personnel.

Pechiney has made a significant commitment to the development of solidification modeling to predict casting quality. The model it has developed and is commercially supplying is called SIMULOR, an integrated model which addresses the liquid from filling the cavity to final solidification, yielding an integral simulation model. SIMULOR integrates easily into any process from initial design to manufacture and provides integral visualization of mold behavior at the pre-design stage. With SIMULOR it is possible to predict the integral behavior of a mold to a high degree of accuracy before the mold has been designed. Even though the calculations and the background are highly complex, SIMULOR is extremely easy to use. User friendliness and interactivity are the main features of its language, and many foundries in Europe and some in the United States are using this solidification modeling software.

Fig. CRV.4. Billet casting: ALTHIX^TM EM-stirred DC casting.

Trends observed and discussed during the WTEC team's visit are summarized below:

For aluminum, 80% of the castings are used for automotive applications
Pechiney anticipates new parts for aluminum brakes
For the specific application of wheels, in Europe 25% of the wheels produced are aluminum; this figure is 40% in the United States
All cylinder heads and pistons in Europe are made of aluminum
50% of engine blocks made in Europe are aluminum
In Europe about 62% of aluminum casting is done via high pressure die casting; 27% is done via sand casting

The French have excellent expertise in semipermanent mold technology and do not excel in die casting technology, whereas this is the reverse for the Italians. In contrast to Japan, many parts made in Japan via squeeze casting are made by permanent mold in France. Lost foam technology is not penetrating in France. The problem of folds and the difficulty of not being able to detect via x-rays are major obstacles.

In 1995 Pechiney produced 70,000 tons of primary and 50,000 tons of secondary aluminum (compared to 100,000 tons of casting produced at GM in 1995). As indicated earlier, a major asset of Pechiney is its expertise in secondary aluminum production.

The R&D facilities at Pechiney are quite impressive, and it is a major research laboratory in metal casting in France.

Published: March 1997; WTEC Hyper-Librarian