Automotive lightweighting is an important way to achieve energy saving and emission reduction in the automotive field. Automotive lightweighting is a comprehensive project integrating material technology, manufacturing technology, and structural design technology, including the application of lightweight materials, new manufacturing technology and techniques, and advanced structural optimization or design methods, which is reflected in three aspects of product structure, material, and manufacturing.
Aluminum alloy is an excellent lightweight material because of its low density, only one-third of steel, good workmanship, corrosion resistance, vibration damping, weldability, and easy recycling. The weight reduction effect of traditional structural parts can reach 30%-40% after aluminum replaces steel. After the weight reduction of the body, the brake system and suspension, and other parts can be designed to be lighter due to the reduced load, thus bringing secondary weight reduction, and the weight reduction effect can reach 50%. Therefore, aluminum alloy as a structural material to replace steel can bring a significant weight reduction effect. At the same time, aluminum has the characteristics of easy recycling. According to the analysis of the European Aluminum Association, 95% of the aluminum material can be recycled after the end of the car, and 95% of the energy consumption can be saved compared with the production of primary aluminum.
According to the statistics of the European Aluminum Association, the amount of aluminum used in each motor vehicle in Europe has increased significantly in the past 20 years, from 50 kg in 1990 to 140 kg in 2012, and is expected to reach 160 kg in 2020, and the amount of aluminum used in some models has even exceeded 500 kg.
At present, the aluminum used in automobiles is mainly concentrated in the drive system, transmission components, suspension components, drive train, brake system, and other positions. With the further improvement of technology, the application scope will extend the castings to the hood, fenders, car doors, rear compartment, roof, whole body, and other large parts which are now mainly steel castings, and the penetration rate will be further improved. Aluminum alloy parts of new energy vehicles mainly include the body, wheels, chassis, crash beam, floor, power battery, seats, etc. The body includes the body skeleton made of high-performance aluminum and the skin and doors made of high-precision aluminum plate. Aluminum for automobiles is mainly put into use in the automotive industry in three forms: die-casting, extrusion, and calendering, of which die-casting aluminum accounts for about 80% of the usage.
According to the experiment, a 10% weight reduction of gasoline passenger cars can reduce 3.3% fuel consumption, 15% weight reduction can reduce 5% fuel consumption; diesel passenger cars can reduce 3.9% and 5.9% fuel consumption respectively; electric vehicles (including plug-in hybrid vehicles) can also reduce 6.3% and 9.5% of electrical energy consumption respectively.
