Error 404--Not Found

From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:

10.4.5 404 Not Found

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent.

If the server does not wish to make this information available to the client, the status code 403 (Forbidden) can be used instead. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address.

Error 404--Not Found

Error 404--Not Found

From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:

10.4.5 404 Not Found

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent.

If the server does not wish to make this information available to the client, the status code 403 (Forbidden) can be used instead. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address.

The battle of the metals
The aluminum angle


Ford's PNGV P2000 vehicle features a stamped and welded aluminum body unit similar in overall concept to a conventional steel body.


Ford's PNGV P2000 vehicle features a stamped and welded aluminum body unit similar in overall concept to a conventional steel body.


The Prodigy's lighter body enables smaller vehicle systems, including powertrain and suspension.

By most accounts, aluminum is the most recently discovered commonly used metal, and exists naturally only in combination with other materials such as silicates and oxides. Although early civilizations used aluminum-bearing clays to make pottery and aluminum salts to make dyes and medicine, it was not until 1808 that Sir Humphrey Davy established the existence of aluminum and named it. It took another 17 years for Hans Christian Oersted to isolate it, and it has been produced commercially only since 1854. It was not until 1886 that two scientists, Paul Louis Toussaint Héroult in France and Charles Martin Hall (founder of the Aluminum Company of America, or Alcoa) in the U.S., separately but simultaneously invented the electrolytic process that is the basis of all aluminum production today, the Hall-Héroult process. By contrast, the Iron Age, characterized by mankind's smelting of iron and its use in industry, began before 1000 B.C.

Considering its relatively recent entrance into not only the automotive industry but the metal industry as well, aluminum has made great strides in grabbing a respectable amount of the automotive spotlight from steel. According to the Aluminum Association, between 1991 and 1999 the use of automotive aluminum doubled, and is expected to double again by 2005. A report released by the Ducker Research Co. in 1999 stated that 61.9% of passenger car and light truck aluminum content is castings for drivetrain components such as engine blocks, cylinder heads, and manifolds. Another 12.9% of the aluminum content of a typical North American-built car or light truck is aluminum foil, largely for heat exchangers such as the radiator. According to the report, the remaining aluminum applications include wheels (15.7%, mostly castings), exterior trim and interiors (4.6%), chassis and suspensions (2.6%), closure panels (1.2%, mostly hoods), body structures (0.7%), and bumper systems (0.4%).

The above percentages will no doubt fluctuate before stabilizing if the use of aluminum grows as predicted. For example, Alcan Aluminum invested $200 million since the early 1990s to develop the special alloys for the Ford Partnership for a New Generation of Vehicles (PNGV) P2000 body and many of its structural parts. Alcan's investment also yielded a new bonding and welding technology required to build the P2000, which is about 40% lighter than a Ford Taurus. Researchers at Ford Forschungszentrum Aachen (FFA) have also been busy investigating a number of advanced lightweight materials and manufacturing techniques. Their aim is a familiar one, which is to develop solutions that allow lightweight vehicles to be built in high volumes at competitive cost.

The body alone accounts for about 25% of the total mass of a typical vehicle and offers the greatest potential for mass savings. FFA considers aluminum as the currently most favored material, as it is much lighter than steel, and widely available. Aluminum has one-third the density of steel, which means a component can be 1.5 times thicker than a steel version while retaining a 50% mass advantage. It can also absorb twice as much energy as steel at the same mass. Aluminum has a naturally high resistance to corrosion due to an invisible oxide film formed on exposure to air. Its corrosion resistance may be further improved by an electrolytic anodic oxidation treatment, known as anodizing, in which a thicker and more adherent oxide skin is developed. However, the construction of aluminum car bodies presents a number of challenges.

Aluminum is more difficult to weld and stamp than steel, and behaves differently when stressed, which means engineering a body structure to meet crash safety and stiffness requirements demands a different approach. Some manufacturers currently offering aluminum bodies use a spaceframe with attached aluminum panels, but this approach cannot be produced in high volume at low cost.

The P2000 features a stamped and welded aluminum body unit similar in overall concept to a conventional steel body, but uses advanced design and technology to achieve a stiff and safe structure. The front shock towers, for example, are light castings, eliminating the need for a heavier, more complex, more costly three-piece aluminum stamping. The P2000 also features epoxy adhesive weld bonding to improve rigidity. The resulting body-in-white (BIW) has a mass of 182 kg (401 lb), compared with 398 kg (877 lb) for a conventional steel version. Overall, the P2000 is made of about 332 kg (733 lb) of aluminum as well as significant amounts of magnesium and plastics, contributing to a total mass of about 907 kg (2000 lb).

Some of the technologies used in the P2000 program were transferred to the platform of the prototype hybrid electric vehicle (HEV) Ford Prodigy family sedan unveiled at the North American International Auto Show (NAIAS) in January. Ford considers the Prodigy to be an interim step between the P2000 and an affordable production hybrid. Aluminum was used extensively for major components such its direct-injection aluminum engine and the body. Additionally, carbon fiber, magnesium, and titanium were used in a variety of body parts for further mass savings. The Prodigy's total mass is 1083 kg (2387 lb), which is approximately 454 kg (1000 lb) lighter than an average family sedan.

General Motors Corp.'s PNGV vehicle, the Precept, makes extensive use of aluminum throughout its chassis, body, and front-seat frames. It features a 152-kg (335-lb) aluminum spaceframe composed of 64 kg (144 lb) of stampings, 49 kg (108 lb) of extrusions, and 32 kg (71 lb) of castings. The Precept's exterior panels are made of aluminum and composite materials. Its mass is 45% less than a comparable steel design.

The EXS3 is DaimlerChrysler's latest PNGV effort. It has an aluminum powertrain, seat frames, and chassis, and its primary propulsion system is an all-aluminum 1.5-L diesel engine. To give the vehicle's body the needed strength and crash protection, the ESX3 uses tubular aluminum sections, combined with injection-molded thermoplastic body sections.

Another vehicle unveiled at the NAIAS displayed other possible trends for future automotive aluminum use. Volkswagen describes its Advanced Activity Concept (AAC) as an "off-road study," which is essentially a free interpretation of a conventional pickup truck. At the rear of the vehicle, brushed aluminum is used for the underride guard, which protects the vehicle when crossing rough terrain. The vehicle's tailpipes are located at the left and right of the guard. The sills have what Volkswagen describes as a scuff-resistant sheet aluminum trim. Aluminum also makes an aesthetic contribution to the interior of the AAC. About 10 cm (4 in) below the windows appear aluminum strips that continue forward onto the dashboard. Brushed aluminum is also a dominant feature on the center console.

Unveiled at the 1999 Tokyo Motor Show, the Lexus Sport Coupe concept features a retractable aluminum hardtop. In about 20 s, the vehicle is transformed from a coupe into a convertible. The roof unfolds in multiple steps simultaneously for quick, smooth operation. The concept also features an aluminum, double overhead cam V8 engine equipped with variable valve timing with intelligence (VVT-I).

It would be almost impossible to not include the Audi A8 in a discussion about aluminum. Crafted around the Audi Space Frame (ASF), an aluminum spaceframe body technology created in partnership with Alcoa, Inc., the A8 is the first luxury car to earn the dual five-star safety rating for both the driver and front seat passenger under NHTSA's New Car Assessment Program. The ASF is a high-strength aluminum structure in which the large integral aluminum-sheet components also perform a load-bearing function. The actual spaceframe consists of extruded sections joined by vacuum-formed die cast nodes. Acting as a safety cell, the ASF's aluminum alloy structural members absorb energy better in relation to their weight than steel. Less mass also translates into lower kinetic energy levels, so a collision in an Audi A8 would in theory involve less deformation. Under collision loads, the long members in the front and rear are designed to crumple in accordion-like fashion, absorbing energy and sparing the remaining central structure.

Through the use of magnesium, aluminum, and plastics, the mass of the A8 4.2-L, DOHC engine has been reduced to 200 kg (441 lb). Adopting valve gear with pressure-cast aluminum cam followers and low-friction contact rollers has led to a reduction in mean friction pressure while simultaneously increasing valve lift by comparison with the bucket-tappet design. Moreover, this reduces the moving masses in the valve gear, enabling the engine to run safely at up to 6200 rpm. The wheel carriers, front and rear suspension links, brake calipers, shock absorber mountings, and wheels of the A8 are all made of aluminum, helping to reduce unsprung mass.

Error 404--Not Found

Error 404--Not Found

From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:

10.4.5 404 Not Found

The server has not found anything matching the Request-URI. No indication is given of whether the condition is temporary or permanent.

If the server does not wish to make this information available to the client, the status code 403 (Forbidden) can be used instead. The 410 (Gone) status code SHOULD be used if the server knows, through some internally configurable mechanism, that an old resource is permanently unavailable and has no forwarding address.