New energy vehicles Reshape the landscape: How does aluminum alloy die-casting Respond to the Structural Changes in body and chassis

New energy vehicles Reshape the landscape: How does aluminum alloy die-casting Respond to the Structural Changes in body and chassis

If you keep an eye on the cutting-edge of new energy vehicle manufacturing, you will surely notice a distinct trend: the vehicle body is increasingly resembling a complete skeleton rather than a frame composed of hundreds of parts. Behind all this lies the automotive industry's ultimate pursuit of lightweighting and safety, and the high-pressure die-Casting Technology of aluminum alloys is becoming the core driving force to realize this vision. However, in the face of increasingly complex "one-piece" large components, the process itself is also evolving. Especially in fields with strict requirements for structural integrity, low-pressure casting technology is demonstrating its irreplaceable unique advantages.

I. The dual propositions of "slimming down" and "strengthening the backbone" of new energy Vehicles
The rise of new energy vehicles has fundamentally changed the underlying logic of automotive design. The "three-electricity system" (battery, motor, and electronic control) brings additional weight, making "range anxiety" an inescapable shadow. Studies show that reducing the weight of electric vehicles by 10% can cut their electricity consumption by approximately 6.3% and increase their driving range by 14%. Therefore, lightweighting is no longer merely an option for enhancing performance, but a survival rule concerning the core competitiveness of products.

At the same time, higher body rigidity is the foundation for ensuring handling stability and passive safety, and it is also the physical prerequisite for the stable operation of high-level autonomous driving sensors. How to lose weight while strengthening the muscles and bones poses a huge challenge to traditional manufacturing processes.

Aluminum alloy has become the preferred material to solve this contradiction due to its excellent strength-to-weight ratio, good machinability and recyclability. Market forecasts indicate that by 2025, the domestic market size of automotive aluminum alloys is expected to exceed 260 billion yuan. However, the sharp increase in the use of aluminum alloys, especially when applied to body structural components and chassis safety parts, has led to a bottleneck in the traditional "stamping + welding" process path - aluminum alloy welding is difficult and costly, and the connection points are prone to become weak points in the structure.

Ii. Integrated Die Casting: The Efficiency Revolution and Technological Boundaries in the Wave
Against this backdrop, integrated high-pressure die-casting emerged. Tesla was the first to integrate the rear floor of the Model Y from over 70 parts into one large die-cast part, achieving an astonishing effect of reducing weight by 30% and lowering manufacturing costs by 40%. This efficiency revolution has rapidly swept across the world. From new forces like NIO and XPeng to traditional giants such as Volvo and Volkswagen, all are actively making plans.

The charm of integrated die casting lies in its ability to die-cast multiple components in one go through integrated design, significantly reducing the number of parts and connection processes, and increasing production efficiency by 30% to 50%. By 2025, the domestic market size of integrated die-Casting Parts is expected to reach nearly 30 billion yuan.

However, when the industry turns its attention to chassis structural components (such as subframes and steering knuckles) and large unitized body frames, which have more stringent requirements for mechanical properties, fatigue strength and internal quality, traditional high-pressure die-casting faces challenges. Especially for super-large hollow structures with complex reinforcing ribs inside, how to ensure the smooth filling of molten metal in the ultra-long flow channel, avoid entrainment, and achieve uniform solidification in areas with significant wall thickness differences is the key to ensuring the compactness and structural reliability of the castings. At this point, the value of another Casting Process was re-evaluated and highlighted.

Iii. Low-pressure Casting: An irreplaceable precision art in critical safety fields
While the industry is abuzz with discussions about high-pressure die-casting, a latest technological breakthrough has revealed another possibility for us. Recently, the world's first all-aluminum load-bearing large frame formed by an integrated low-pressure casting process was officially released. This "aluminum-gold bone beam" with a projection area of 4.2 square meters has a thinnest part of only 4 millimeters and a thickest part of 50 millimeters, successfully achieving synchronous high-quality forming under extreme wall thickness differences.

Unlike the "high-speed injection" in high-pressure die casting, in low-pressure casting, compressed air is introduced into a closed holding furnace, allowing the molten metal to smoothly fill the mold cavity from bottom to top at a lower pressure. This technological feature brings several core advantages:

Outstanding metal quality: Smooth filling, significantly reducing turbulence and entrainment, with fewer internal pores and oxide inclusions in the castings, and superior bulk performance.

Outstanding compactness: It crystallizes and solidifies under pressure, providing better feeding effect. The casting structure is dense, and the mechanical properties, especially fatigue strength, are high.

Competent for complex hollow structures: Highly suitable for manufacturing complex structural components with closed inner cavities that require the placement of sand cores, which is a typical feature of many chassis safety parts (such as steering knuckles). Academic research indicates that the low-pressure casting process is a feasible and high-quality solution for manufacturing safety components like steering knuckles that bear complex multi-axis loads.

In short, when it comes to core structural components such as the chassis of new energy vehicles and large thin-walled frames that are crucial to the ultimate safety and performance of vehicles, low-pressure casting, with its ability to produce high-quality and highly reliable castings, occupies an irreplaceable ecological position. Industry research also clearly indicates that for such super-large and structurally complex components, low-pressure casting remains the primary forming method.

Iv. The Road Ahead: The Co-evolution of High and Low Voltage
The lightweighting journey of new energy vehicles is not an either-or technological elimination competition, but rather a process co-evolution based on the functional requirements of different components. The manufacturing landscape of the future will become increasingly clear

Large body panels, rear underbody panels, etc. : Will continue to be dominated by integrated high-pressure die-casting, pursuing the ultimate production efficiency and integration.

Chassis suspension components, steering knuckles, large load-bearing frames, etc. : Low-pressure casting will be further applied in its areas of expertise, providing reliable "bones" and "joints" for vehicles, and constantly breaking through the technological limits such as super-large thin-walled structural components.

For vehicle manufacturers and Tier 1 suppliers, understanding the characteristic boundaries of these two mainstream aluminum alloy forming processes and conducting the optimal component design and supply chain layout based on this will become the key to building the core competitiveness of the next-generation new energy vehicle platform. For material and manufacturing enterprises, this means that they must simultaneously possess a profound understanding of both processes and the ability to provide customized technical solutions.

This manufacturing revolution driven by new energy vehicles is far from over. It is moving from merely "weight reduction" to a deeper level of "structural reconstruction" and "maximizing material performance". In this process, whether it is high-pressure die-casting or low-pressure casting, both will jointly shape the body and soul of the next generation of smart electric vehicles on the stage they are most proficient in.