Automobile Materials SRJC - ENGR 45 Semester Project (Fall ’09)

1. Automobile MaterialsSRJC - ENGR 45 Semester Project (Fall ’09) Brian Goff Mario Grasso Oscar Briceno

2. Some Background... • Cars at first were built entirely of wood, and later of wood frames with steel body panels. • In the early 1900’s, the idea of a body-on-frame design came about. • These vehicles had • a load-bearing chassis • that supported all the • mechanical parts • and a body usual made • of steel. Ford Model T Courtesy Car Body Design http://www.carbodydesign.com/articles/2005-04-13-chassis-history/2005-04-13-chassis-history.php

3. Moving Forward... Honda Civic Frame http://automobiles.honda.com/images/2009/civic-sedan/safety/safety-header.jpg • Today, most smaller vehicles such as small SUV’s and sedans use a unibody (or monocoque) construction. • Heavy-duty vehicles like trucks and busses still use the idea of body-on-frame. • Regardless of the construction technique, steel is still the predominant material used in automotive frames.

4. A Quick Comparison Typical Ladder Frame Monocoques

5. What it’s all About • Today, the new revolution in car design is the use of new materials in the vehicle structure. • As fuel economy restrictions become tighter, manufacturers must find new ways to meet them. • This has led them away from using so much steel in the vehicles, and more and more are moving towards aluminum. • The central theme of our project was to compare these new lightweight aluminum cars to their steel predecessors and see if anything is being sacrificed and/or gained.

6. A Basic Comparison • Two common alloys used in car manufacturing: • For Aluminum: AA 5182 • For Steel: AISI 1020 Data Courtesy efunda http://www.efunda.com/materials/alloys/carbon_steels/show_carbon.cfm?ID=AISI_1020&prop=all&Page_Title=AISI%201020 http://www.efunda.com/materials/alloys/aluminum/show_aluminum.cfm?ID=AA_5182&show_prop=all&Page_Title=AA%205182

7. Properties • Density of Steel: 7.88 g/cm3 • Density of Aluminum: 2.7 g/cm3 • Aluminum is about 3 times lighter than steel per unit volume, but can be made just as strong using certain alloys/shapes/bonding methods. • Because of this, AL parts can be thicker, and thus stronger, than their steel counterparts, all while weighing less.

8. The Cost Issue • While Al may seem like a miracle metal for car production, there is a reason not all cars are made from Al... It costs a lot more than Steel.

9. The Move to Aluminum • The first production vehicle to move to an Al frame was the Audi A8 in 1994. • This allowed Audi to make their full-size car lighter than the competitions (BMW, Mercedes,Lexus...), thus giving them the edge in performance & handling. • This comes at a price premium though, for instance compared to a Lexus LS460 (Steel framed) which costs around $65,000. The A8 starts at $75,000 Audi A8 Lexus LS460

10. An Increasing Trend http://www2.prnewswire.com/mnr/duckerworldwide/37515/

11. Cars Utilizing Al Frames • Audi A8 • Jaguar XJ • Corvette Z06 • Honda NSX • Audi A2 • Audi R8

12. Weight • The most obvious advantage to using aluminum in place of steel in cars is aluminum weighs less. Cars with Mostly Al Space Frames

13. Safety • Not too many safety tests have been performed on Al framed vehicles due to their usually higher price. • However, the Audi A2 is an inexpensive compact car that has been tested, and received overall favorable reviews compared to its steel bodies counterparts.

14. Some other advantages... • There are some manufacturing methods that can only be done with aluminum, such as extrusions. • These extrusions allows the Al Space Frame to have about half the amount of parts as a traditional steel monocoque. • Because of all this, Al is already a cheaper material to use for low volume production cars (under 100,000 units a year or so).

15. A Few Other Facts... • Today, the average car contains about 200 pounds of aluminum parts. • Aluminum space frames (like that from Audi), contain fewer parts and fewer connection nodes, which helps keep production costs lower.

16. In The Future http://andrewbeard.wordpress.com/2009/05/11/technology-carbon-fiber-monocoque-chassis/ • While Aluminum may be the wave of the future for now, some exotic car companies are already looking ahead to composite materials. • Take for example Porsche Carrera GT, which used a completely Carbon-Fiber monocoque construction in addition to Carbon-Fiber body panels. • Because of this, the curb weight of the car was only 3000 lbs., even with a 5.7L V-10 engine powering it. Porsche Carrera GT http://upload.wikimedia.org/wikipedia/commons/thumb/6/65/Porsche_Carrera_GT_-_Goodwood_Breakfast_Club_%28July_2008%29.jpg/800px-Porsche_Carrera_GT_-_Goodwood_Breakfast_Club_%28July_2008%29.jpg

17. References • Building an aluminum carhttp://www.allbusiness.com/professional-scientific/scientific-research-development/443897-1.html • History of Automobile Body and Chassishttp://www.carbodydesign.com/articles/2005-04-13-chassis-history/2005-04-13-chassis-history.php • Automobile Bodies: Can Aluminum Be an Economical Alternative to Steel?http://www.tms.org/pubs/journals/JOM/0108/Kelkar-0108.html • Different Types of Chassishttp://www.autozine.org/technical_school/chassis/tech_chassis2.htm • Aluminum Versus Steelhttp://www.travistrailer.com/public/pag16.aspx