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

Brian GoffBrian Goff

Mario GrassoMario Grasso

Oscar BricenoOscar Briceno

Some Background...Some Background...Cars at first were built entirely of wood, and Cars at first were built entirely of wood, and later of wood frames with steel body panels.later of wood frames with steel body panels.

In the early 1900’s, the idea of a body-on-In the early 1900’s, the idea of a body-on-frame design came about.frame design came about.

These vehicles hadThese vehicles hada load-bearing chassisa load-bearing chassisthat supported all thethat supported all themechanical partsmechanical partsand a body usual madeand a body usual madeof steel.of steel.

Ford Model TFord Model TCourtesy Car Body DesignCourtesy Car Body Design

http://www.carbodydesign.com/articles/2005-04-13-chassis-history/2005-04-13-chassis-history.phphttp://www.carbodydesign.com/articles/2005-04-13-chassis-history/2005-04-13-chassis-history.php

Moving Forward...Moving Forward...

Heavy-duty vehicles like trucks and busses still Heavy-duty vehicles like trucks and busses still use the idea of body-on-frame.use the idea of body-on-frame.

Regardless of the construction technique, steel is Regardless of the construction technique, steel is still the predominant material used in still the predominant material used in automotive frames.automotive frames.

Today, most smaller Today, most smaller vehicles such as small vehicles such as small SUV’s and sedans use a SUV’s and sedans use a unibody (or unibody (or monocoque) monocoque) construction.construction.

Honda Civic FrameHonda Civic Framehttp://automobiles.honda.com/images/2009/civic-sedan/safety/safety-header.jpghttp://automobiles.honda.com/images/2009/civic-sedan/safety/safety-header.jpg

A Quick ComparisonA Quick Comparison

MonocoquesMonocoques

Typical Ladder FrameTypical Ladder Frame

What it’s all AboutWhat it’s all AboutToday, the new revolution in car design is the Today, the new revolution in car design is the use of new materials in the vehicle structure.use of new materials in the vehicle structure.

As fuel economy restrictions become tighter, As fuel economy restrictions become tighter, manufacturers must find new ways to meet manufacturers must find new ways to meet them.them.

This has led them away from using so much This has led them away from using so much steel in the vehicles, and more and more are steel in the vehicles, and more and more are moving towards aluminum.moving towards aluminum.

The central theme of our project was to The central theme of our project was to compare these new lightweight aluminum cars compare these new lightweight aluminum cars to their steel predecessors and see if anything to their steel predecessors and see if anything is being sacrificed and/or gained.is being sacrificed and/or gained.

A Basic ComparisonA Basic ComparisonTwo common alloys used in car manufacturing:Two common alloys used in car manufacturing:

For Aluminum: AA 5182For Aluminum: AA 5182

For Steel: AISI 1020For Steel: AISI 1020

SteelSteel AlAl

Yield Yield StrengthStrength

(MPa)(MPa)294.8294.8 395395

UTS (MPa)UTS (MPa) 394.7394.7 420420

Hardness Hardness (HB500)(HB500) 104104 5858

Data Courtesy efundaData Courtesy efundahttp://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%205182http://www.efunda.com/materials/alloys/aluminum/show_aluminum.cfm?ID=AA_5182&show_prop=all&Page_Title=AA%205182

PropertiesProperties

Density of Steel: 7.88 g/cm3Density of Steel: 7.88 g/cm3

Density of Aluminum: 2.7 g/cm3Density of Aluminum: 2.7 g/cm3

Aluminum is about 3 times lighter than steel Aluminum is about 3 times lighter than steel per unit volume, but can be made just as per unit volume, but can be made just as strong using certain alloys/shapes/bonding strong using certain alloys/shapes/bonding methods.methods.

Because of this, AL parts can be thicker, and Because of this, AL parts can be thicker, and thus stronger, than their steel counterparts, all thus stronger, than their steel counterparts, all while weighing less.while weighing less.

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

The Move to AluminumThe Move to AluminumThe first production vehicle to move to an Al The first production vehicle to move to an Al frame was the Audi A8 in 1994.frame was the Audi A8 in 1994.

This allowed Audi to make their full-size car This allowed Audi to make their full-size car lighter than the competitions (BMW, lighter than the competitions (BMW, Mercedes,Lexus...), thus giving them the edge in Mercedes,Lexus...), thus giving them the edge in performance & handling.performance & handling.

This comes at a price premium though, for This comes at a price premium though, for instance compared to a Lexus LS460 (Steel instance compared to a Lexus LS460 (Steel framed) which costs around $65,000. The A8 framed) which costs around $65,000. The A8 starts at $75,000starts at $75,000

Audi A8Audi A8

Lexus LS460Lexus LS460

An Increasing TrendAn Increasing Trend

http://www2.prnewswire.com/mnr/duckerworldwide/37515/

Cars Utilizing Al FramesCars Utilizing Al Frames

WeightWeightThe most obvious advantage to using aluminum in The most obvious advantage to using aluminum in place of steel in cars is aluminum weighs less.place of steel in cars is aluminum weighs less.

Cars with Mostly AlCars with Mostly AlSpace FramesSpace Frames

SafetySafetyNot too many safety tests have been performed on Not too many safety tests have been performed on Al framed vehicles due to their usually higher price.Al framed vehicles due to their usually higher price.

However, the Audi A2 is an inexpensive compact However, the Audi A2 is an inexpensive compact car that has been tested, and received overall car that has been tested, and received overall favorable reviews compared to its steel bodies favorable reviews compared to its steel bodies counterparts.counterparts.

Some other Some other advantages...advantages...There are some manufacturing There are some manufacturing methods that can only be done methods that can only be done with aluminum, such as with aluminum, such as extrusions.extrusions.

These extrusions allows the Al These extrusions allows the Al Space Frame to have about half Space Frame to have about half the amount of parts as a the amount of parts as a traditional steel monocoque.traditional steel monocoque.

Because of all this, Al is already a Because of all this, Al is already a cheaper material to use for low cheaper material to use for low volume production cars (under volume production cars (under 100,000 units a year or so).100,000 units a year or so).

A Few Other Facts...A Few Other Facts...

Today, the average car contains about 200 Today, the average car contains about 200 pounds of aluminum parts.pounds of aluminum parts.

Aluminum space frames (like that from Audi), Aluminum space frames (like that from Audi), contain fewer parts and fewer connection contain fewer parts and fewer connection nodes, which helps keep production costs nodes, which helps keep production costs lower.lower.

In The FutureIn The FutureWhile Aluminum may be the wave of the future While Aluminum may be the wave of the future for now, some exotic car companies are already for now, some exotic car companies are already looking ahead to composite materials.looking ahead to composite materials.

Take for example Porsche Carrera GT, which used Take for example Porsche Carrera GT, which used a completely Carbon-Fiber monocoque a completely Carbon-Fiber monocoque construction in addition to Carbon-Fiber body construction in addition to Carbon-Fiber body panels.panels.

Because of this, the curb weight of the car was Because of this, the curb weight of the car was only 3000 lbs., even with a 5.7L V-10 engine only 3000 lbs., even with a 5.7L V-10 engine powering it.powering it.

http://andrewbeard.wordpress.com/2009/05/11/technology-carbon-fiber-monocoque-http://andrewbeard.wordpress.com/2009/05/11/technology-carbon-fiber-monocoque-chassis/chassis/

Porsche Carrera GTPorsche Carrera GThttp://upload.wikimedia.org/wikipedia/commons/thumb/6/65/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/800px-Porsche_Carrera_GT_-_Goodwood_Breakfast_Club_%28July_2008%29.jpg_Goodwood_Breakfast_Club_%28July_2008%29.jpg

ReferencesReferencesBuilding an aluminum carBuilding an aluminum carhttp://www.allbusiness.com/professional-scientific/scientific-research-development/http://www.allbusiness.com/professional-scientific/scientific-research-development/443897-1.html443897-1.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 Automobile Bodies: Can Aluminum Be an Economical Alternative to Steel?to Steel?http://www.tms.org/pubs/journals/JOM/0108/Kelkar-0108.htmlhttp://www.tms.org/pubs/journals/JOM/0108/Kelkar-0108.html

Different Types of ChassisDifferent Types of Chassishttp://www.autozine.org/technical_school/chassis/tech_chassis2.htmhttp://www.autozine.org/technical_school/chassis/tech_chassis2.htm

Aluminum Versus SteelAluminum Versus Steelhttp://www.travistrailer.com/public/pag16.aspxhttp://www.travistrailer.com/public/pag16.aspx