# New Energy Vehicle Aluminum Alloy Explosion-Proof Valve Die Castings: A Dual Guardian of Lightweight Design and Safety

In the wave of rapid development in the new energy vehicle industry, aluminum alloy die-cast parts have become a key material for core components such as power battery systems and vehicle body structures, thanks to their lightweight properties, high strength, and excellent corrosion resistance. Among these, aluminum alloy explosion-proof valve die-casts serve as the first line of defense for battery safety, and their performance directly impacts the range, safety, and reliability of new-energy vehicles.

### I. Aluminum Alloy: The "Golden Material" for Lightweighting New Energy Vehicles

Aluminum alloy has a density only one-third that of steel, yet its strength can be engineered through alloying to match or even surpass steel. For instance, according to data from the International Aluminium Association, every kilogram of aluminum used in a car can replace 2.25 kilograms of steel—and with optimized structural design, further weight reductions are possible, leading to an overall weight reduction exceeding 50%. This characteristic is particularly crucial in the field of new-energy vehicles, where battery systems typically account for 30% to 40% of the vehicle’s total weight. Lightweighting not only significantly boosts the vehicle’s range but also enhances efficiency. Take Tesla’s Model Y, for example: after adopting an integrated die-cast underbody that consolidates over 70 individual parts into a single component, the vehicle achieved a 30% weight reduction and a 10%-11% increase in range—while simultaneously cutting battery costs by 20%.

Aluminum alloys also excel in their machinability. They have a low melting point and excellent fluidity, allowing complex structures to be formed in a single step via die-casting. Moreover, their surface precision can reach as high as ±0.01 mm, perfectly meeting the stringent requirements of power battery explosion-proof valves for sealing performance and dimensional accuracy. Additionally, aluminum alloys boast a thermal conductivity three times higher than steel, enabling rapid dissipation of heat generated during battery charging and discharging—and ultimately helping to extend the battery's lifespan.

### II. Explosion-Proof Valve: The "Safety Sentinel" of Power Batteries

Power batteries may generate large amounts of gas under conditions such as overcharging, deep discharging, short circuits, or high temperatures. If the pressure exceeds a critical threshold, it can lead to battery swelling in mild cases—or even trigger an explosion in severe scenarios. As the safety valve for the battery pack, the burst valve must open precisely when the pressure reaches its set threshold, releasing the accumulated gas before automatically closing again, thereby preventing electrolyte leakage and blocking external moisture from entering.

The core advantage of aluminum alloy explosion-proof valve die castings lies in the perfect combination of their material properties and manufacturing process:

1. **High Strength and Toughness**: By adding elements such as silicon and magnesium, the tensile strength of aluminum alloy can reach over 300 MPa, while maintaining an elongation rate of 10%-15%. This ensures that the explosion-proof valve remains deformation-free and crack-resistant even under high-pressure impacts.

2. **Precision Molding Capability**: The die-casting process enables micron-level control over the internal flow channels of the explosion-proof valve, ensuring unobstructed gas release pathways. For instance, the battery pack’s explosion-proof valve in NIO ET5 utilizes high-pressure casting, with flow channel diameter tolerances maintained within ±0.02 mm, reducing the response time to as little as 0.1 second.

3. **Corrosion Resistance**: An dense oxide film forms naturally on the surface of aluminum alloys, enabling them to maintain stable performance even in harsh environments such as electrolytes and salt spray. Experimental data show that after being immersed in a 5% NaCl solution for 500 hours, the tensile strength of the aluminum alloy explosion-proof valve decreased by less than 5%.

### III. Technological Breakthrough: A Comprehensive Upgrade from Materials to Processes

1. **Heat-Treat-Free Materials**: Traditional die-cast parts typically require heat treatment to relieve internal stresses, but high temperatures can cause deformation of the explosion-proof valves. In recent years, breakthroughs have been made in the development of heat-treat-free aluminum alloy materials (such as C611 and THAS), which exhibit a 20% improvement in fluidity and threefold enhancement in resistance to thermal cracking. These materials can now be directly molded via die casting, boosting the yield rate to over 95%.

2. **Ultra-Large Die Casting Machine**: Integrated design of explosion-proof valves with battery pack housings is becoming a trend. Lingjin Group has launched a 9,000-ton die casting machine capable of producing large structural components such as rear floor panels and front engine compartments in a single molding process, reducing the number of parts from over 200 to fewer than 10—and shortening the production cycle by 70%.

3. **Intelligent Detection Technologies**: Non-destructive testing techniques such as X-ray flaw detection and ultrasonic testing can precisely identify internal defects in explosion-proof valves, including air pockets and cracks. For instance, the battery pack’s explosion-proof valve in the XPeng G6 utilizes an AI-powered visual inspection system, achieving a defect detection accuracy rate of up to 99.9%—ensuring that every product meets stringent safety standards.

### IV. Market Prospects: The "Hidden Champion" of a Trillion-Yuan Industry

According to statistics, China's aluminum alloy die-casting parts market reached 207.6 billion yuan in 2023, with the new energy vehicle sector accounting for over 40% of this figure. As the "New Energy Vehicle Industry Development Plan (2021-2035)" continues to advance, China's new energy vehicle sales are expected to account for 20% of total automotive sales by 2025, driving the aluminum content per vehicle up to 250 kg. Meanwhile, market demand for precision die-cast components such as explosion-proof valves is set to experience a sustained surge.

Currently, China has established a leading enterprise cluster represented by Guangdong Hongtu, Wencan Shares, and Aikedi. Their products not only supply domestic automakers such as Tesla, NIO, and XPeng, but are also exported to markets in Europe and North America. Looking ahead, as technologies like solid-state batteries and 800V high-voltage platforms become more widespread, explosion-proof valves will need to withstand even higher pressures and temperatures. Consequently, aluminum alloy die-cast components will continue evolving toward enhanced strength, superior thermal conductivity, and lightweight designs.

From material innovation to process revolution, from safety protection to performance enhancement, aluminum alloy explosion-proof valve die-cast components are quietly leading the way—as "hidden champions"—as new-energy vehicles move toward a safer, more efficient, and more sustainable future.