0102030405
Die-casting technology, the "behind-the-scenes hero" of automobile light weighting
2025-06-05
In recent years, with the rapid development of new energy vehicles, the die-casting body integrated molding process has become the focus of publicity by major manufacturers. Die-casting frequently appears in various media. As one of the important technologies for achieving lightweight automobiles, this process has attracted much attention.
1. What is die casting?
Die Casting is a Precision Manufacturing process that injects molten metal into a mold cavity under high pressure (10-150MPa) and high speed (10-70m/s), and rapidly cools and forms it. Its principle is similar to making cookies with a mold, but the raw material is high-temperature molten metal, and the filling and solidification must be completed in a very short time, ultimately obtaining high-precision, complex-structured metal parts.
Core Process:
a, Molten metal: low melting point alloys such as aluminum and magnesium are heated to liquid state;
b, High-pressure injection: The molten metal is injected into the mold at high speed through the die-casting machine;
c, Cooling molding: The metal solidifies rapidly in the mold to form parts;
d, Post-processing: removing burrs, surface treatment, etc.
2. Why has die-casting become the "darling" of new energy vehicles?
Under the trend of lightweight and electrification of automobiles, die-casting technology stands out due to its three major advantages: high efficiency, cost reduction, and strong performance:
a, Quantitative demand: Aluminum alloy die-castings are 30%-40% lighter than traditional steel components, significantly improving the range of electric vehicles.
b, Revolution in production efficiency: Integrated die-casting integrates hundreds of parts into 1-2 large castings, shortening production time from several hours to 2-3 minutes.
c, Cost control: The rear floor of Tesla Model Y is made through integrated die-casting, which reduces manufacturing costs by 31% and factory area by 30%.
Typical cases:
Tesla: The Model Y rear floor uses one die-cast part to replace 79 parts, reducing 1,600 welding points.
Xiaomi Auto: Self-developed 9,100-ton super die-casting machine achieves “zero welding” on the rear floor of the car body, increasing production efficiency by 10 times.
SERES M9: After the body is formed in one go by a 9,000-ton die-casting machine, the number of parts is reduced from 222 to 10, and the body rigidity is increased by 30%.
3. Advantages and disadvantages of die-casting integrated body
Advantages:
a,High precision: dimensional tolerance reaches CT4-CT6 level, surface roughness Ra1.6-6.3μm, can be directly used for precision parts;
b,Material utilization rate exceeds 90%: Liquid metal is injected on demand, with very little scraps and a recovery rate of up to 95%;
c, High design freedom: complex rib structures can be manufactured to improve the collision energy absorption performance of the vehicle body.
Disadvantages:
a,High maintenance cost: the Integrated Die Casting needs to be replaced as a whole if it is damaged;
b,Equipment and material barriers: The cost of a single large die-casting machine exceeds 40 million yuan, and the heat-treatment-free aluminum alloy and high-vacuum mold technology rely on imports;
c, Yield rate bottleneck: The yield rate of traditional steel car bodies exceeds 99%, while that of integrated die-castings is only 80%-90%, and the problems of porosity and stress concentration need to be solved.
4. How does China lead the global die-casting market?
a, Equipment breakthrough: Only four companies in the world can produce die-casting machines above 6,000 tons, three of which are from China (LK, Haitian Metal, and Yizumi). The 16,000-ton die-casting machine jointly developed by Xiaopeng and LK has been put into use.
b,Material innovation: Lizhong Group, Shuai Yichi and others have developed aluminum alloys that do not require heat treatment, and SERES has launched magnesium alloy die-casting technology, which has further increased the weight reduction effect by 30%.
c,Intelligent upgrade: Xiaomi introduced an AI simulation system and completed 10.16 million material simulation experiments. The quality inspection process used X-ray + AI to detect microscopic defects.
d, Industry forecast: In 2025, the scale of China's integrated die-casting market may reach 27.2 billion yuan, and the market space for die-casting machines will exceed 6 billion yuan.
5. Future Trends
From “larger tonnage” to “more sustainable”.
a, Material innovation: magnesium-aluminum alloy composite die-casting and semi-solid forming technology, taking into account both lightness and strength;
b,Intelligent process: AI real-time mold temperature control increases the yield rate to 98%, and 3D printing + die-casting hybrid manufacturing is accelerated;
c,Green Manufacturing: Integrated die-casting reduces carbon emissions by 15%-18%, and the magnesium alloy recovery rate exceeds 95%.
6.Conclusion: Die casting is more than just “car manufacturing”
From mobile phone mid-frames to aviation components, die-casting technology is reshaping the manufacturing industry with "efficiency, precision, and low carbon". With breakthroughs in the entire chain of equipment, materials, and processes, China has become the core engine of global die-casting innovation.