Aluminum is an alloy material composed of aluminum and other elements such as copper, magnesium, silicon and zinc. Aluminum itself is a lightweight metal with good electrical and thermal conductivity, as well as excellent corrosion resistance. By adding other elements, the mechanical properties of aluminum can be improved and enhanced, such as strength, hardness, wear resistance, etc., thus extending its range of applications. Aluminum alloys play an important role in the manufacture of automobiles
Lightweight Aspect
The weight of a car has a significant impact on fuel efficiency and performance. According to relevant data, for every 50kg reduction in vehicle weight, the distance traveled per liter of fuel can increase by 2km; a 1% reduction in vehicle weight can improve fuel efficiency by 0.6% – 1%. Aluminum alloys have low density, and replacing traditional steel structures with aluminum alloy structures can reduce vehicle weight by 30% – 40%, engines can be made 30% lighter, and wheels can be made 50% lighter. For example, the Audi A8L6.0 quattro sedan uses a W12 engine, and due to the use of lightweight materials such as aluminum alloys in the engine part, the overall weight of the vehicle is reduced to 1980kg, lower than other models, and the power is strong, with only 4.7kg of weight needed to accelerate per horsepower, comparable to high-performance sports cars.
Performance Enhancement Aspects
Good Thermal Conductivity: Aluminum alloys have excellent thermal conductivity. In terms of engine components, with the development of engine technology, four-valve structures have become the mainstream design trend. Components such as pistons, radiators, oil pans, cylinder blocks, cylinder heads, and crankcases in automobile engines are made of aluminum alloy materials, which help dissipate heat from the engine, improving its work efficiency and performance. Currently, using aluminum alloy to replace cast iron in engines has become the mainstream trend.
Strength and Durability: Although aluminum alloys have a low density, they can achieve certain strength requirements through various alloy additions and processing treatments. They possess high strength and durability, meeting the various mechanical requirements of cars during driving and ensuring their safety and reliability.
Cost Savings Aspect
Raw Material Costs: In the long run, as the production scale of aluminum alloys expands and manufacturing processes improve, unit costs gradually decrease. Moreover, due to the high recyclability of aluminum alloys, the cost of recycling and reusing is relatively low, which can save costs throughout the entire lifecycle of a vehicle.
Manufacturing and Processing Costs: Aluminum alloys have excellent plasticity and are suitable for casting, forging, and stamping processes. Cast aluminum alloys are used the most in automobiles (accounting for over 80%). Aluminum alloy parts produced by die-casting have a high yield rate, can reduce wall thickness and subsequent machining, have good surface quality and dimensional accuracy, and are well suited for mass production, thereby reducing manufacturing costs.
Enhanced Security Aspects
For example, foam aluminum AFS (aluminum foamsandwich) has a high stiffness/weight and strength/weight ratio, can effectively absorb impact energy, has shock and noise resistance, is easy to recycle, etc. It can be applied to safety-related parts such as door pillars, bumpers, side door beams, front collision beams, etc., enhancing the safety of automobiles.
Wide Application of Components
Engine Components: This includes pistons, cylinder heads, cylinder blocks, oil pans, and crankshafts. The use of aluminum alloys in engine manufacturing for lightweight purposes is most evident, typically resulting in a weight reduction of more than 30%. For instance, Nissan used a new VQ series V6 cast aluminum cylinder block engine and aluminum valve pushrods in the new Maxima model. By adopting high-pressure die casting technology to make the cylinder block thinner, the weight was reduced by more than 50% compared to the original V6 cylinder block.
Body Parts: Body panels such as doors, trunks, and body panels, engine hoods, seats, floor pans, and fenders can be produced using corrosion-resistant aluminum or hard aluminum. Many concept cars from American manufacturers like Ford and General Motors, as well as Japanese Honda and German Audi, have adopted aluminum alloys for their bodies, resulting in a weight reduction of over 40% compared to steel structures. The main aluminum alloys used for body panels are AL-Mg-Si, AL-Cu-Mg, AL-Mg, and AL-Mg-Zn-Cu systems. Furthermore, in recent years, the use of aluminum has increased in car bumpers and doors for lightweighting purposes. Resin coating has become the mainstream for small car surfaces, with reinforcement materials supplementing iron-based rigid components, fiber-reinforced plastics, and aluminum parts. The trend towards full aluminumization is becoming increasingly evident.
Chassis and Suspension Components: Chassis structural components, brackets, and suspension parts are also gradually adopting aluminum alloys, which contribute to the overall lightweight design of automobiles.
Other Components: Also used in clutch shells, heat exchangers, brackets, wheels (including hubs, etc.), decorative parts, etc. The United States, Japan, and Germany are the countries that use aluminum alloys the most in cars. For example, the body of German Volkswagen Audi A8, A2, and Japanese NXS uses 80% aluminum alloy. In China, except for Shanghai Santana, First Automobile Works Audi and Jetta (all imported production lines) use aluminum alloy, domestic cars use more Red Flag models, about 80-100 kg.
Aluminum alloy, with its unique physical and chemical properties, has become one of the important and indispensable materials in modern society.