Automobile lightweight can effectively reduce the weight of automobile, which is one of the main directions to realize automobile energy saving and emission reduction. Automotive lightweight materials mainly use light alternative materials, improve the manufacturing process of body parts, and optimize the design of body structure. The small series mainly starts with one of the three methods of lightweight materials, and briefly analyzes its application trend by introducing the classification of five alternative materials.

The development of the automobile industry is currently facing three major issues: resources, safety and environmental protection. Many developed regions have formulated countermeasures and measures such as fuel consumption and emission regulations. In the response of the automotive industry, automotive lightweight materials have been verified as one of the effective methods to solve these three problems.

The ratio of car quality to fuel consumption and emission reduction is 5:4.

The power and power transmission system required for car driving are closely related to the quality of the car. After reducing the quality, the car can perform the same performance under low traction. When a car is running, 75% of the fuel consumption is related to the quality of the vehicle. Reducing the quality of the car can effectively reduce fuel consumption and emissions. The quality is reduced by 10%, the fuel consumption is reduced by 8%, and the emissions are reduced by 4% (Figure 1). Therefore, from the perspective of automobile industry development and social environmental requirements, it is of great significance to reduce automobile quality, improve fuel economy and environmental performance.

5 Alternative Materials Applications for Automotive Lightweight Materials Including Bodies, Frames and Parts

(1) High-strength steel plates have high tensile strength and yield strength, and are mainly suitable for vehicle core frame members. It has the characteristics of high tensile strength and high yield strength, and can maintain performance on the basis of the reduction of steel sheet and car body weight. In recent years, it has been increasingly applied to automobile frames. According to its characteristics, it can be divided into low-strength steel, High-strength steel and ultra-high-strength steel. The material is mainly used in the core structure of AB column, floor, threshold and other vehicles.

(2) Aluminum alloy is corrosion-resistant and has strong wear resistance. It is used to transition from the internal parts cover to the entire aluminum body. It has good density, strength, rigidity, elasticity, impact resistance, corrosion resistance and wear resistance. It is an ideal material for lightweight automobiles. Aluminum alloy was used in automobile engine hood and trunk lid in the early stage. At present, it has developed into the application of all-aluminum body. Among them, aluminum alloy and aluminum composite materials are used in automobiles. At present, more than 80% of aluminum alloy and aluminum composite materials are used abroad. Aluminum alloys used in automobiles are divided into cast aluminum alloys and wrought aluminum alloys. At present, more than 60% of the cars in the industry are made of aluminum, and the energy consumption of 1t aluminum alloy with recycled aluminum is 95% less than that of processing and manufacturing 1t.

(3) Magnesium alloy has good bending strength and sound insulation performance, and is used in body structure and parts. Under the condition of constant bending stiffness, using magnesium instead of steel can be reduced by 61%. Under the condition of constant bending strength, using magnesium instead of steel can be reduced by 74%. Using 1kg of magnesium each time can reduce the life of the car by 30kg of exhaust emissions. Magnesium alloy also has sound insulation performance, which proves that it can improve the comfort of the car.