Due to the addition of components such as batteries and motors, new energy vehicles significantly increase in overall weight. Compared to traditional fuel vehicles, the total vehicle weight can increase by 50% or even 100%, with some new energy vehicles reaching 3-4 tons.

This weight increase undoubtedly places higher demands on vehicle driving safety and controllability, particularly in terms of collision safety. Different types of collisions occur at varying rates. The heavier the vehicle, the greater the challenge for energy-absorbing components to effectively absorb and transfer impact energy during short-distance deceleration.

However, new energy vehicles have great potential for weight reduction. Whether for fuel or new energy vehicles, a 10% reduction in total vehicle weight can increase driving range by 5-8%, significantly improving carbon reduction effects throughout the vehicle’s lifecycle.

Automotive lightweight design can be achieved through structural optimization, process improvements, and material selection. Material lightweight solutions include polymeric materials such as carbon fiber, glass fiber, composites, and light alloys such as aluminum, magnesium, and titanium alloys.

Light alloys are mainly used to replace steel materials. Additionally, different components have varying performance requirements, necessitating matched forming processes and product designs.

Cast aluminum alloys are mainly used in manufacturing new energy vehicle engine components, housing parts, and chassis components, such as engine blocks, cylinder heads, clutch housings, bumpers, wheels, and engine mounts.

Wrought aluminum alloys, including rolled, forged, and extruded materials, are primarily used in car bodies, such as engine hoods, roofs, doors, fenders, trunk lids, floor panels, body frames, and covering parts.

The aluminum alloys used in new energy vehicles mainly include 2xxx, 3xxx, 5xxx, 6xxx, and 7xxx series.

The 2xxx series is mainly used for body structures, 3xxx series for heat exchangers and battery housings, 5xxx series for body panels, and 6xxx series for extruded profiles and various powertrain and suspension components.

Heat exchanger materials are mainly composed of 3xxx, 4xxx, 7xxx, or 6xxx series aluminum alloys. The 3xxx series aluminum alloys are often used for battery housings due to their good formability, low yield ratio, high strain hardening index, large plasticity index, low deformation resistance, and low through-thickness anisotropy index.

1. Body Structure

Extrusion Forming: Typically uses 6000 series aluminum alloys, such as 6061 and 6082. Aluminum ingots are heated and placed in an extrusion machine to form profiles of various cross-sections for body frame production.

Stamping: Uses aluminum sheet metal, which is cut and stamped on pressing machines through dies to form components like doors, engine hoods, and trunk lids.

Welding: Uses arc welding, laser welding, and other welding technologies to connect extruded and stamped parts into body structures, requiring controlled welding parameters to ensure weld quality and joint strength.

2. Engine and Transmission System

Casting: Mainly uses 3000 and 4000 series aluminum alloys, such as 380 for cylinder blocks and 4032 for pistons. Casting processes include gravity casting, pressure casting, and centrifugal casting. Gravity casting is suitable for complex-shaped cylinder blocks; pressure casting offers high production efficiency and casting precision for small engine components; centrifugal casting produces dense structures for high-performance components.

Machining: Post-casting parts undergo turning, milling, drilling, and other operations to meet dimensional accuracy and surface roughness requirements.

3. Chassis and Suspension System

Forging: Generally uses 7000 series aluminum alloys, such as 7075. Aluminum alloy billets are heated and subjected to pressure on forging equipment to undergo plastic deformation, significantly improving material strength for manufacturing critical components like suspension control arms and steering knuckles.

Heat Treatment: Forged components undergo solution treatment and aging to further enhance their mechanical properties.

4. Interior and Electrical Systems

Drawing: For components like electrical wires and cables, 1000 series pure aluminum is drawn through dies to produce wire of required diameters.

Bending and Stamping: Uses 5000 series magnesium-containing aluminum alloys, such as 5052, to form sheet metal into instrument panels, seat frames, and other interior components through bending and stamping processes.

5. Wheels

Casting: Predominantly uses A356 aluminum alloy, with gravity casting and low-pressure casting technologies. Gravity casting is simple and practical, while low-pressure casting effectively improves casting quality and mechanical properties.

Machining: Cast wheels undergo turning, drilling, and other operations to ensure dimensional and mounting accuracy.

Battery Components

Battery Housing

Advantages: Aluminum’s low density effectively reduces overall battery weight, improving new energy vehicle range; excellent corrosion resistance protects internal battery structures in complex environments; good thermal conductivity facilitates battery cooling, ensuring operation within suitable temperature ranges.

Process: Usually produced using die casting processes, such as high-pressure die casting, which can produce complex, high-precision housings with high production efficiency.

Battery Tray

Advantages: High strength and stiffness to support battery pack weight and provide good support; excellent fatigue resistance to withstand various vibrations and impacts during vehicle operation.

Process: Mainly uses extrusion forming to produce aluminum profiles of different cross-sections and dimensions according to design requirements, followed by welding assembly into trays.

Energy conservation, emission reduction, and lightweight design can improve overall vehicle range and represent trends in the automotive industry, especially for new energy passenger vehicles. Body lightweight design is the most important approach, and aluminum alloy materials are the ideal raw materials. With advantages including abundant reserves, natural corrosion resistance, good mechanical properties, excellent formability, and reasonable costs, aluminum alloys are increasingly being applied in new energy vehicle body manufacturing.