In modern thermal management technologies, liquid cooling plates serve as critical components for heat dissipation in electronic devices, industrial machinery, and other fields due to their high-efficiency heat conduction performance. Their working principle relies on the circulation of cooling fluid within the channels, which carries away heat through heat exchange to achieve temperature reduction of target components. However, in practical applications, the channels of liquid cooling plates face severe corrosion problems, which not only affect heat dissipation efficiency but may also lead to the failure of the entire cooling circulation system. Therefore, in-depth research on this issue is of significant practical importance.
The corrosion of liquid cooling plate channels primarily originates from the selection of cooling fluid and the oxides and bacteria generated as the fluid contacts air. These factors erode the channel materials, roughening the inner walls of the channels, increasing fluid flow resistance, and reducing the circulation efficiency of the cooling fluid. Additionally, corrosion products continuously accumulate, blocking the channels and causing a sharp decline in heat dissipation performance. Due to the lack of regular maintenance by most users, the performance of liquid cooling plates deteriorates over time, eventually leading to component damage due to overheating.From a material perspective, liquid cooling plate channels made of different materials exhibit distinct characteristics in corrosion resistance and application scenarios:
1. Aluminum-Based Channels
Aluminum is widely used in manufacturing liquid cooling plates, with common types including 6063 and 1100 series aluminum alloys. Channel fabrication methods are diverse, such as milling channel structures directly on aluminum plates via CNC machining, pressing round aluminum tubes into aluminum plates to form channels, or using die casting processes. While aluminum offers advantages like low density and cost-effectiveness, its chemically active nature makes the aluminum plate surface highly prone to reacting with oxygen in contact with air and cooling fluid, generating bacteria and forming oxides such as aluminum trioxide. These oxides often appear as white flocculent substances that gradually accumulate over time, eventually blocking the entire cooling circulation system and severely impacting the heat dissipation efficiency of liquid cooling plates.
2. Copper-Based Channels
Copper-based liquid cooling plates typically use copper alloy materials such as C102 or C1100. Channel fabrication often relies on CNC precision machining, or standard copper tubes can be directly used to construct channel structures. Compared to aluminum, copper has excellent oxidation resistance and is highly resistant to corrosion in cooling fluids, maintaining long-term stable performance. However, when copper contacts air, oxygen can generate corrosion products such as copper chloride. Although the corrosion process of copper is relatively slow, its corrosion products still accumulate over time, eventually causing channel blockages—though its service life is longer than that of aluminum-based channels.
3. Stainless Steel-tube Channels
304 stainless steel is a commonly used material for manufacturing liquid cooling plate channels. It features stable chemical properties and strong resistance to oxidation when exposed to air, making it an ideal choice for channel materials. Additionally, titanium alloy stainless steel tubes offer a higher corrosion resistance rating and are widely used in cooling circulation systems in industrial applications due to their exceptional corrosion resistance, capable of adapting to more complex and harsh environments.
4. Advantages and Disadvantages of the Three Channel Materials
• Aluminum Channels:
◦ Advantages: Excellent thermal conductivity, low cost, and lightweight, meeting diverse application needs and commercialization requirements. The low density helps effectively control overall equipment weight, facilitating installation and transportation.
◦ Disadvantages: Chemically active, prone to oxidation and corrosion, with resulting oxides blocking channels and shortening the service life of liquid cooling plates. Frequent maintenance is required, increasing operational costs and management complexity.
• Copper Channels:
◦ Advantages: Superior oxidation resistance and strength, ensuring excellent stability in cooling fluid environments and maintaining consistent heat dissipation performance over extended periods.
◦ Disadvantages: Higher density increases equipment weight, and the relatively high cost of copper raises production costs. Corrosion products still form upon air contact, posing long-term channel blockage risks.
• Stainless Steel Channels:
◦ Advantages: Exceptional chemical stability and corrosion resistance (especially for 304 stainless steel and titanium alloy stainless steel tubes), suitable for complex and harsh environments, with long service life and low maintenance frequency.
◦ Disadvantages: Relatively poor thermal conductivity compared to aluminum and copper, potentially affecting heat dissipation efficiency; higher machining difficulty and manufacturing costs.
5. Material Selection and Cooling Fluid Optimization Strategies
The selection of liquid cooling plate channel materials must closely align with practical application requirements.
In highly corrosive environments like marine or high-salt settings, use titanium alloy or 304 stainless steel for their excellent corrosion resistance. This ensures your equipment runs stably for a long time. For food-grade applications, 304 food-grade stainless steel is essential to prevent harmful substance migration and ensure food safety.
In addition to material selection, optimizing cooling fluids is key to reducing channel corrosion. Cooling fluids are mainly divided into two categories: pure water and formulated coolants.
• Pure Water: Ultra-pure water free of impurities and oxygen can be used, or the entire circulation system can be modularly sealed to minimize air contact, reducing oxidation and microbial growth risks. Antifreeze can also be added to prevent freezing in low-temperature environments and maintain system stability.
• Formulated Coolants: These are prepared by mixing pure water, formulated chemicals, and antifreeze. The chemical formulations typically include inhibitors, biocides, and reducing agents:
Inhibitors form protective films on channel surfaces to slow corrosion.
Biocides eliminate microorganisms in the fluid to prevent biological corrosion.
Reducing agents regulate the fluid’s redox potential to inhibit oxidation reactions.
>These components work synergistically to significantly reduce channel corrosion risks and enhance the reliability and service life of liquid cooling plates.
6. Comparison Between Pure Water and Formulated Coolants
• Pure Water Coolant:
Requires no specialized skills, low cost, and no real-time monitoring.
High compatibility with copper and aluminum channels.
Technically transparent and widely applicable. Maintenance involves monthly conductivity testing to assess corrosion levels—higher conductivity indicates increased ionic impurities from corrosion, prompting timely replacement or cleaning.
• Formulated Coolants:
Require professional technical guidance from suppliers, higher cost, and regular chemical replenishment.
Formulations must be tailored for copper and aluminum due to their different corrosion behaviors.
Core chemical compositions are trade secrets, with non-public technical details.
Commonly used in large-scale servers and data centers requiring heat dissipation stability.
7. Cleaning and Maintenance Strategies for Corrosion Products in Liquid Cooling Plates
Scientific cleaning and maintenance are critical to ensuring stable operation of liquid cooling plates:
• Routine Maintenance: Use high-pressure cleaning to remove dust and debris from channels, and regularly inspect and lubricate components. When idle, completely drain internal fluids to prevent residual corrosion.
• Metal Corrosion Product Removal:
◦ Acid Cleaning: Circulate acidic fluids to dissolve metal oxides, monitoring pH values. After dissolution, drain, neutralize, and flush with pure water until inlet/outlet pH values are consistent, ensuring no residue.
• Microbial and Organic Contaminant Removal:
◦ Alkali Cleaning: Circulate alkaline fluids to kill microorganisms and decompose organic matter, using pH monitoring to assess effectiveness. Drain, neutralize, and flush with pure water until pH balance is achieved.
These procedures ensure thorough removal of corrosion products and contaminants, maintaining the high-efficiency and stable operation of liquid cooling plates.
