Can Die-cast Aluminum Alloy Auto Parts Improve the Heat Dissipation Efficiency of Electric Drive Systems in New Energy Vehicles?
Publish Time: 2025-12-16
In today's rapidly developing new energy vehicle market, the electric drive system, as one of the core "three electrics" (electric motor, electronic control, and electronic control system), directly determines the vehicle's power, energy efficiency, and reliability. However, high power density operation also brings severe thermal management challenges—if heat cannot be dissipated in time, it will lead to overheating failure of semiconductor devices, demagnetization of magnets, and even system shutdown. Die-cast aluminum alloy auto parts, with their excellent thermal conductivity, lightweight characteristics, and ability to form complex structures, are becoming a key solution for improving the heat dissipation efficiency of electric drive systems.1. The Inherent High Thermal Conductivity of Aluminum Alloys Lays the Foundation for Heat DissipationAluminum alloys have a thermal conductivity of approximately 96–150 W, far exceeding that of engineering plastics and superior to many steels. This means that under the same temperature difference, aluminum alloys can more efficiently conduct heat generated by heat sources such as motor windings and IGBT modules to the outer casing surface, and then quickly dissipate it through air cooling or liquid cooling systems. Die casting integrates heat sink fins, flow channels, and mounting cavities into a single housing, maximizing the continuity of the heat conduction path and avoiding interfacial thermal resistance caused by splicing multiple parts, thus significantly improving overall heat dissipation efficiency.2. Die casting enables integrated design of complex heat dissipation structures.New energy vehicles have extremely high space utilization requirements, and traditional welded or assembled heat sink housings are insufficient to meet compact layout needs. Die casting can manufacture housings with complex geometric features such as internal cooling channels, dense external heat dissipation ribs, and irregularly shaped mounting bosses in a single molding process. For example, motor end caps or electrical control boxes can be directly integrated with serpentine liquid cooling channels through die casting, allowing coolant to flow closely to the back of the heat-generating chip for efficient heat exchange. This "structure as function" design concept not only improves heat dissipation performance but also reduces the number of sealing surfaces, lowers the risk of leakage, and improves system reliability.3. End-to-end post-processing ensures performance and durability.While die-cast aluminum alloy auto parts possess good thermal conductivity potential, a rigorous subsequent process chain is needed to unlock their full value. The standard process includes:Stamping and deburring/grinding: Removing gates and flash to ensure smooth assembly surfaces;Shot peening: Introducing surface compressive stress to improve fatigue strength and extend service life under vibration;CNC machining: Precision machining of mounting holes, sealing surfaces, and mating surfaces to ensure dimensional accuracy and airtightness;Surface treatment: Selecting powder coating, anodizing, electrophoresis, or passivation based on the application environment.It is particularly noteworthy that while anodizing slightly reduces surface thermal conductivity, the resulting dense oxide film prevents long-term thermal performance degradation due to corrosion; and the special passivation treatment used for the inner walls of liquid cooling channels can significantly improve resistance to coolant corrosion without significantly affecting heat exchange efficiency.4. Lightweighting and heat dissipation synergistically contribute to improved energy efficiencyDie-cast aluminum alloy auto parts have low density, reducing weight by 30%–60% compared to cast iron or steel housings. In new energy vehicles, every kilogram of weight reduction translates into a small but cumulative increase in driving range. More importantly, its excellent heat dissipation capabilities allow the electric drive system to operate continuously at higher power densities, reducing energy waste caused by power descent due to overheating and indirectly improving overall vehicle energy efficiency. This dual advantage of "lightweight design + efficient heat dissipation" makes it the preferred material solution for high-end electric drive platforms.In summary, die-cast aluminum alloy auto parts not only naturally meet heat dissipation requirements due to their high thermal conductivity, but also achieve structural and functional integration through the die-casting process, and ensure long-term reliability through a complete post-processing procedure. In the context of new energy vehicles pursuing high performance, high integration, and long lifespan, it has transformed from an "optional" to a "must-have."
