May/June_AMP_Digital

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 | M A Y / J U N E 2 0 1 8 2 6 the company had been working on its own Voiture Populaire (VP) since 1941. It too was a lightweight alumi- num bodied concept with a similar front drive, two-cylinder air-cooled boxer engine, and four-speed trans- mission, but as a four-door sedan. On October 19, Grégoire took Paul Panhard (nephewof company founder René Pan- hard) for a 500-mile test drive in an AFG, and a week later PL and Grégoire signed a contract to develop the concept to production. This was the beginning of an accelerated development that tran- sected the last year of occupation, the liberation, the ensuing turmoil and aus- terity, and even an attempt from the French Ministry of Industrial Production to ration automobile production. Despite these challenging times, on December 14, 1945, PL was able to present the Dyna VP2 to the Service des Mines for homologation. It was a radical design that rode on a lightweight steel chassis with a cast aluminum space- frame supporting a mostly aluminum shell. The sill outers, floorpan, trunk floor, and front fender support were steel. It was not a one-off luxury body, but was intended for series production, which meant developing stamping tools. An established tool and die sup- plier estimated tool development at 10 months, but it required twice the time A new alloy, AG3 (Al + 2.5-3.7%Mg) had to be developed to overcome form- ability issues so severe that early parts had to be annealed between stamping steps. The car was officially introduced at the 1946 Paris Salon 11 months lat- er—the Panhard Dyna X. Production was delayed due to a shortage of raw materials, but slowly ramped up from 50 a month in January 1948 to 200 by December. The first aluminum inten- sive production car was on its way. Sev- eral derivatives would eventually be offered, including a convertible and station wagon/delivery vans. Howev- er, by 1952 the car looked dated and sales began to decline. When produc- tion stopped in 1954, PL had produced 47,049 units, including 33,093 sedans. Another notable development oc- curred in post-WWII U.K., where the Rover Co. developed a light agricultural and utility vehicle, a cross between a Willys Jeep and a tractor. By the time the first three prototypes were shown at the 1948 RAI automobile exhibition in Amsterdam, the classic Land Rover was born. As a utility vehicle, it need- ed none of the baroque styling of the Dyna X. It was a simple flat sided vehi- cle on a steel chassis, with an alumi- num body using N4 aluminum alloy (2% Mg, 0.25% Mn; predecessor to alloy 5251) sheet [11] produced by the Northern Aluminium Co., U.K. The styl- ing was specifically chosen to eliminate the need for expensive stamping tools. The floor used the same alloy but at a higher temper and thicker gauge. That simplicity was key to its long-term suc- cess: Intended for a two to three year production stint to earn precious ex- port currency, these three prototypes were instead a smash hit that grew into their own brand and whose direct de- scendants remained in production until 2016. ~AM&P Note: Look for the second part of this article series in the July/August issue of AM&P. For more information: Laurent Chap- puis, president, Light Metal Consultants LLC, 8600 Church Rd., Grosse Ile, MI 48138, lbchappuis@icloud.com. References 1. https://aluminiumleader.com/ application/transport/. 2. D.F. Martin, The Race for Cheap Aluminum: Hall Versus Heroult, Chem- istry Faculty Publications, Paper 6, University of South Florida, http://scholarcommons.usf.edu/ chm_facpub/6. 3. http://montana-aluminum.com/ part-i-a-new-metal-age. 4. The Aluminium Courier, No. 16, Alu- minium Development Assoc., London, 1951. 5. B.W. McCalley, Model T Ford – The Car that Changed the World, ISBN 0-87341-293-1, 1994. 6. Benson Ford Research Center, Model T archives, Accession #1701, Box #13. Print version dated 7.28.1913. 7. Model T archives, Accession #1701, Box #13, Benson Ford Research Center. 8. Q.R. Skrabeck, Aluminum in Amer- ica: A History, p 99-103, ISBN 978- 0786499557. 9. W.S. Peterson and R.E. Miller, Cast Shop Technology and Reclamation: 100 Years of Progress, Hall-Heroult Centennial: First Century of Aluminum Process Technology: 1886-1986, TMS, 2002. 10. D. Beare, Panhard − The Flat-Twin Cars 1945-1967 and Their Origins V2, Stinkwheel Publishing, ISBN 978-0- 9547363-2-3, 2017. 11. F.G. Woolard, The Development of the Aluminium Automobile, The Alu- minium Courier, No. 16, Aluminium Development Assoc., London, p 8-9, Sept. 1951. 1951 Panhard Dyna X, with a cast aluminum spaceframe supporting a mostly aluminum shell on a lightweight steel chassis. 1948 Rover Co. Land Rover Series I with sheet aluminumbody on a steel chassis. Courtesy of Wikimedia Commons/ DeFacto.