How does die-casting technology become an “invisible driving force”

2025-07-17

With the explosive growth of new energy vehicles, the electric drive system is the most critical system of the entire electric new energy vehicle. Its efficiency, weight and cost directly determine the competitiveness of the vehicle. However, industry discussions often focus on motor design and battery energy density, but rarely mention a key link - die-casting process.

In fact, from the motor housing to the battery pack bracket, the lightweight and performance breakthroughs of electric drive components are inseparable from the continuous innovation of die-casting technology. High vacuum die-casting, integrated molding, semi-solid process... How do these "invisible drivers" help the advancement of electric drive systems? Die-casting technology is currently the most cost-effective lightweight molding technology. Which top die-casting suppliers have made great contributions to rewriting industry rules? They are rewriting industry rules with their die-casting technology.

Die-casting requirements for electric drive components: lightweight, high precision, low cost

1.Motor housing: Traditional cast iron is heavy and has poor thermal conductivity, which affects heat dissipation. With efficient and low-cost die-casting technology, aluminum alloy motor housing has become the mainstream. Die-casting technology can produce 3mm die-castings, and even 2mm can still be well formed. High-performance aluminum alloy die-castings have high tensile strength (tensile strength ≥ 250MPa). The use of high-vacuum aluminum die-casting motor housing can reduce weight by 35% compared to cast iron; the use of high-vacuum aluminum alloy die-casting can even reach 40%. In recent years, there has been a trend of magnesium alloy replacing aluminum alloy, which can reduce weight by more than 50% compared to cast iron and can be 10~20% lighter than aluminum alloy die-castings (depending on different models, complexity, design indicators and loads).

2. Inverter housing: The requirements for electromagnetic shielding and sealing are extremely high. High vacuum aluminum alloy die castings can control the porosity of die castings to (≤0.3%) and integrate cooling water channels. For example, the Tesla V3 electric drive system die-casts the inverter and motor housing into one, reducing 40% of connectors, which well meets the needs of the inverter housing.

3. Battery pack structural parts: Integrated die-casting replaces Sheet Metal Welding, greatly improving the structural rigidity of components and the entire vehicle (by more than 30%), while reducing costs by 20% and reducing weight by more than 20%.

How does die-casting technology solve the pain points of the electric drive industry?

1. Lightweight and strength: Using high-strength aluminum alloy (such as A380, AlSi10MgMn) and magnesium alloy, combined with high vacuum die-casting (porosity <0.5%), tensile strength exceeds 300MPa, elongation reaches 10%, and weldable die-castings, completely achieving a weight reduction of 30%~50%.

2. High integration: Reduce the number of parts through ultra-large integrated die-casting (such as die-casting machines above 6000T), and pre-embed inserts/cooling pipelines through the insert process to improve structural rigidity.

3. Reduce costs and increase efficiency: Develop heat-treatment-free alloys (such as AlSi9MnMoZr) to eliminate the heat treatment step, and intelligent mold temperature control reduces the scrap rate to less than 2%.

4. Heat dissipation and sealing: integrated conformal cooling channel, high vacuum die-casting (≤5mbar) combined with nano-coating to achieve IP69K protection.

5. Sustainable manufacturing: Recycled aluminum alloys (such as ADC12-R) and low-carbon magnesium alloys reduce carbon emissions by 75%.

Typical cases: Tesla and NIO use integrated die-casting to reduce weight by 25%; BYD achieves IP69K through high vacuum die-casting; LK, Yizumi, Haitian, and Buhler provide key equipment and process support. Die-casting technology is driving the upgrade of electric drive to "fewer parts, higher performance, and lower cost".