Wrought Aluminum Technologies for Automobiles: Part Two

Aluminum may best be used by redesigning the dimension of the part to suit its characteristics. In this way, rigidity can be restored or even enhanced without increasing weight. The limit to this process is the increase in susceptibility to buckling failure.

The latest models of the Corvette automobile, among others, are a good example of redesigning parts to make best use of aluminum's advantages. The aluminum chassis and suspension parts of these cars have large overall dimensions for stiffness but are lightened by reducing cross-sectional area and removing unneeded metal. As a result, they are not only equally or more durable and stiff than the steel parts they replace, but they possess an airy gracefulness that most people find attractive. Similarly, aluminum bicycle frames can be optimally designed so as to provide rigidity where required, yet exhibit some extra flexibility, which functions as a natural shock absorber for the rider.

A sampling of those wide-ranging applications is listed below.

Air Conditioners - Aluminum is an excellent conductor of heat and is widely used in automotive air conditioner condensers, evaporators, liquid lines, and compressor housings.

Body Panels - Aluminum has been successfully used in hoods, deck lids and other exterior parts in large production volume models of passenger cars, pickup trucks, vans and sport utility vehicles.

Brackets - Aluminum’s combination of strength, resilience, and durability makes it an excellent material for engine mounting and accessory brackets. It is widely used for power steering brackets, pump-mounting brackets, air conditioner mounting brackets, steering column brackets and similar applications.

Brake Cylinders and Pistons - Light weight, corrosion resistance, economy, and reliability explain the choice of aluminum in this important application.

Brake Drums - Strength and durability under exposure to water, road salt and dirt are among the advantages of aluminum in this application. In addition, the heat-transfer capability of aluminum helps to keep brake linings from overheating and so reduces brake “fading” in severe use, an important safety factor.

Bumper Reinforcements - These safety-related parts have high strength, light weight, good forming characteristics, and resistance to corrosive environments.

Charge Air Coolers - In addition to its good heat exchange and corrosion resistance characteristics, aluminum can be readily formed, cast or extruded into complex hollow shapes, as required for this application.

Complete Bodies - Aluminum has been used successfully for complete auto bodies, demonstrating strength, light weight, durability, and excellent crashworthiness. It is the preferred body material for large trucks, buses and other utility vehicles and was selected for the current U.S. Postal Service van, with a projected body life of 24 years.

Drive shafts - this relatively new application of aluminum was prompted by the metal’s combination of high strength, light weight, and corrosion resistance in a severely exposed location.

Engine Heads and Blocks - the engine is one of the heaviest single units in an automobile and offers one of the greatest opportunities for weight saving through the use of aluminum.

Fuel Injection Systems - Aluminum offers weight savings, corrosion resistance, machinability and extrudability, as manufacturers continue to make fuel injection systems smaller and lighter. Aluminum is used for pump housings, tubing and cylinder parts.

Heater Cores - Aluminum is an appropriate material for heater core applications, since it is an excellent conductor of heat and is formable, and can be brazed, soldered or welded.

Intake Manifolds - Aluminum allows the production of intake manifolds in more advanced shapes and with thinner walls than are practical in iron.

Load Floors - its combination of light weight, strength, and corrosion resistance provides a part that can take contact with various materials, weights and impacts, without special protection or maintenance.

Luggage Racks and Air Deflectors - in these parts, aluminum combines esthetic appearance and styling with function and durability in environmental exposure without painting or coatings.

Oil Coolers - Auxiliary engine oil coolers and transmission oil coolers make use of aluminum for efficient heat exchange, durability, and light weight.

Pistons - these moving parts must last for the life of the vehicle in a demanding environment of high heat, stress, and potentially corrosive compounds. Aluminum meets these demands, with the added advantage that its light weight makes engines more responsive and efficient in converting fuel energy into vehicle performance. Aluminum has been the standard material for automobile pistons since the 1950s.

Radiators - throughout automobile history, aluminum has been used in the radiators of selected cars. Now, with new production techniques, automakers are equipping most models with aluminum radiators to take advantage of their light weight, heat-transfer capacity, and corrosion resistance. Aluminum is formable, machinable, and can be brazed, soldered or welded.

Seat Tracks, Shells and Headrests - the mechanical properties of lightweight aluminum alloys and their ease of fabrication make them an advantageous choice for these safety-sensitive parts.

Spare Tire Carrier Parts - these parts are both functional and styled for appearance. Aluminum provides both the necessary functional strength and durability plus the desired styling.

Cost reduction is the major issue for aluminum products to be used more in the automobile applications. It is obviously important for an aluminum manufacturer to reduce cost of their products; however, total cost reduction will require application technologies of aluminum to draw the maximum benefit of using aluminum. Those technologies include cost and parts reductions of peripheral parts by utilizing recyclability and lightness of aluminum.

Finally, when a car must be scrapped aluminum is readily recycled with a high residual scrap value, providing both economic and environmental benefits.

Aluminum, with its wide choice of alloys and tempers, offers a wealth of advantages to automotive engineers developing new car designs of the future.