Technical Analysis of Gravity Die-Casting Liquid Cooling Plate Products
Product Overview
In demanding application scenarios such as heavy industry, new energy vehicles, and outdoor electronic power equipment, thermal management systems are required not only to deliver high-efficiency heat exchange performance, but also to withstand extreme operating conditions including continuous vibration, strongly corrosive media, and alternating high and low temperatures. Conventional heat sinks often suffer from pain points such as weld cracking, pipeline corrosion, severe functional degradation, short service life and high maintenance costs due to single material selection or structural design defects.
With anti-vibration, corrosion resistance and stable performance as its core design concept, the gravity die-cast water-cooled radiators innovatively adopt a composite structure consisting of 316 stainless steel tubes and a gravity-cast A356 aluminum alloy main body. The stainless steel tubes are fully wrapped within the aluminum alloy body, with only stainless steel connectors exposed as water inlets and outlets, which achieve physical isolation of the internal tubing from external corrosive environments at the structural level. Combining the excellent toughness of A356 aluminum alloy and the dense grain structure formed by gravity casting, this product redefines heat dissipation solutions for extreme operating conditions, aiming to provide customers with reliable maintenance-free performance throughout the entire product life cycle.
Technical Analysis of Gravity Die-Casting Liquid Cooling Plate Products
Core Advantages: Comprehensive Breakthroughs from Materials to Structure
Anti vibration design: withstand the test of "Vibration"
To address the risks of pipe weld cracking, loose connections and water leakage caused by equipment vibration during operation, as well as reduced thermal conductivity or even functional failure resulting from separation between pipes and cooling plates, gravity die-casting technology thoroughly resolves structural failure issues through three core technologies.
Integrated main body of A356 by gravity die-casting
● Process Improvement: Replacing conventional welded assembly with gravity die-casting using A356 aluminum alloy.
● Technical Principle: During gravity casting, the molten metal fills the mold smoothly. Combined with modification treatment, the A356 alloy forms a fine and uniform eutectic silicon structure, eliminating internal porosity and shrinkage defects.
● Functional Advantage: Compared with die-cast aluminum, A356 offers higher elongation (up to 6%–10%) and impact toughness. Under vibrating conditions, the main material can undergo slight elastic deformation to absorb energy, instead of cracking directly like brittle materials, thereby fundamentally eliminating the risk of structural fracture.
Fully Wrapped Structural Design:
● Structure: Adopting the gravity die-casting process, the cooling plate main body fully encapsulates the molten A356 aluminum alloy and 316 stainless steel pipelines inside, with only stainless steel connectors reserved as water inlet and outlet.
● Performance: A tight metallurgical bonding interface is formed between the aluminum alloy body and stainless steel pipelines during the casting process, completely eliminating the risk of interface loosening existing in traditional welding or mechanical connection methods. Under continuous high-frequency vibration, the integrated A356 main body acts as the overall load-bearing structure to absorb and disperse vibration energy. The stainless steel pipelines are barely subjected to external alternating stress, fundamentally eliminate the possibility of fatigue failure in the tubing.
Corrosion Resistance: Standing the Test of Time
To cope with humid conditions, salt spray, acid, alkali and other corrosive environments, the gravity casting solution adopts a dual anti-corrosion strategy: structural isolation plus upgraded materials.
Fully Wrapped Structural Design with physical isolation:
● Design Concept: During the manufacturing process, the 316 stainless steel pipelines are fully wrapped by molten A356 aluminum alloy, achieving complete physical isolation between the pipelines and external corrosive environments.
● Performance: External corrosive sources such as salt spray, acid rain and chemical media only contact with the surface of the A356 aluminum alloy main body, and cannot reach the internal stainless steel pipelines. Even under extreme corrosive conditions including high salt spray and strong acid-base environments, the structural integrity of the tubing remains fully protected, completely eliminating the risk of external pipe wall corrosion. Meanwhile, the aluminum alloy cooling plate is fully and directly bonded with the SUS316 tubes, leaving no risk of foreign matter penetration.
SUS304 Stainless Steel Connectors
● Material Properties: The exposed inlet and outlet connectors adopt SUS304 stainless steel, featuring excellent corrosion resistance and superior mechanical strength, suitable for most industrial and outdoor application scenarios.
● Performance: Under regular industrial environments, coastal areas and outdoor working conditions, SUS304 connectors deliver long‑term reliable anti‑corrosion protection, ensuring durable service at all connection points.
Surface Cleaning Treatment for A356 Main Body
● Process Technology: Adopting pickling and passivation for pipelines plus professional surface cleaning processes to remove casting scale and contaminants, forming a clean metallic surface.
● Performance: As an Al‑Si‑Mg alloy, the treated A356 surface forms a uniform natural oxide film, providing a good corrosion resistance foundation in conventional industrial environments. Combined with the physical isolation advantage of the fully wrapped structure, the main body meets anti‑corrosion requirements for the majority of industrial and outdoor applications.
Process & Material Comparative Analysis: Why Choose A356 Over ADC12?
In the manufacturing of radiator main bodies, ADC12 (high-pressure die casting) and A356 (gravity casting with T6 heat treatment) are two mainstream solutions. Although ADC12 features high production efficiency and low cost, A356 gravity casting is firmly adopted for scenarios requiring extreme vibration resistance and high reliability. Below is an in-depth comparison across core technical dimensions:
Comparison Items | Conventional Solution: ADC12 (High-Pressure Die Casting) | Gravity Casting Solution: A356 (Gravity Casting + T6) | Impact on Extreme Operating Conditions |
Core Alloy Composition | Al-Si-Cu series (high copper content) | Al-Si-Mg series (copper-free, magnesium-containing) | Corrosion Resistance: Copper in ADC12 tends to form microcells, reducing corrosion resistance; A356 is inherently superior due to no copper content. |
Mechanical Toughness (Elongation) | Low (<4%), brittle texture, weak impact resistance | High (6%-10%), excellent ductility and impact toughness | Vibration Resistance: Under 20g high-frequency vibration, ADC12 is prone to brittle fracture or microcracks; A356 absorbs vibration energy through elastic deformation to avoid structural failure. |
Internal organizational structure | Fast cooling, prone to porosity and shrinkage defects | Stable filling combined with modification treatment results in fine, dense grains with almost no porosity. | Pressure Resistance & Service Life: Porosity is the origin of fatigue cracks. A356’s dense structure ensures zero-leakage reliability under high water pressure and long-term vibration. |
Heat Treatment Capability | Non-heat-treatable; mechanical properties fixed | T6 heat-treatable (solution + aging); significantly enhanced strength and toughness after treatment. | Comprehensive Performance: After T6 treatment, A356 achieves yield strength above 240MPa while maintaining high toughness, realizing "both strength and toughness". |
Thermal Conductivity | 96-100 W/(m·K)， actual conductivity slightly lower due to internal porosity | 150-170 W/(m·K) (T6 condition); dense structure enables smoother heat transfer paths. | Heat Dissipation Efficiency: Beyond vibration resistance, A356’s thermal conductivity is significantly higher than ADC12, enabling faster heat dissipation. |
Applicable scenarios | Civil electronics, home appliances, low-vibration environments; pursuing low cost and mass production. | Automotive-grade, industrial-grade, marine engineering; pursuing high reliability, long service life, and extreme environment adaptability. | Gravity Casting Positioning: Born for extreme conditions, prioritizing optimal performance over cost considerations. |
Expert Analysis: Why "Brittleness" Is a Fatal Flaw for Heat Exchangers
In laboratory static tests, ADC12 may appear to deliver good strength data. However, under real-world extreme conditions — (such as vibration in off-road vehicles, wave impact on vessels, and resonance in heavy machinery )— the material is subjected to alternating stress.
With low elongation (<4%), ADC12 cannot relieve stress through slight deformation under repeated vibration. Stress rapidly accumulates at grain boundaries or material defects, causing fatigue cracks to propagate instantly and eventually leading to catastrophic fracture and water leakage.
With high elongation (>6%), A356 absorbs vibration energy like a "spring" and resists fracture even under considerable deformation.
Conclusion: By adopting A356 gravity casting, we accept higher material costs and lower production efficiency in exchange for over 3 times longer fatigue life and inherently safe anti-vibration performance. This is a necessary investment for extreme operating conditions.
Material Combination Analysis: Why 316 Stainless Steel + A356?
This product series features an optimized "rigid-flexible integrated" design based on engineering mechanics and thermodynamics principles.
Functional Division Logic
Component | Core Mission | Material Selection Strategy |
Pipeline System | Defender: Withstand internal pressure and ensure zero leakage | 316 Stainless Steel: With high strength and excellent resistance to chloride ion corrosion, it provides reliable performance as a fluid channel. The fully wrapped structure physically isolates it from external corrosive environments, further enhancing long-term reliability. |
Main Body | Conductor: Rapid heat dissipation, high toughness for vibration resistance, complex flow channel forming. | A356 Aluminum Alloy (Gravity Casting): Resists vibration and impact via high elongation and toughness. Gravity casting delivers a dense microstructure for balanced pressure resistance and thermal conductivity. It also acts as an outer structural layer, providing complete physical protection for the internal tubing. |
Connectors | Connector: Inlet & outlet connection, local corrosion resistance. | SUS304 Stainless Steel: Provides good corrosion resistance and excellent mechanical strength, meeting interface anti-corrosion requirements for general industrial and outdoor applications. |
Key Performance Comparison Analysis
Performance | 316 stainless steel (pipeline) | A356 Aluminum Alloy (Gravity Casting Body) | System Benefit After Combination |
Mechanical Toughness | High (high strength, high rigidity) | Extremely high (elongation 6%–10%, superior to die-cast aluminum) | Core anti-vibration advantage: High toughness of A356 prevents brittle fracture under severe vibration, forming “rigid-flexible complementation” with 316 tubing. The fully wrapped structure protects the pipeline from external alternating stress. |
Casting Quality | Seamless or welded pipe | Dense, porosity-free (gravity casting + modification treatment) | Gravity casting eliminates common porosity defects in die casting, greatly improving pressure resistance and long-term reliability of the main body. |
Thermal Conductivity | ~16 W/(m·K) | ~150-170 W/(m·K) (after T6 heat treatment) | A356 exhibits excellent thermal conductivity after T6 treatment, even better than some die-cast aluminum alloys, ensuring efficient heat dissipation. |
Corrosion Resistance | Extremely high (molybdenum-containing) | Excellent (forms uniform natural oxide film after surface cleaning) | Fully wrapped structure provides physical isolation so the pipeline itself does not contact corrosive media. SUS304 connectors satisfy anti-corrosion requirements in general applications. |
Core Performance Comparison: Gravity Casting vs. conventional heat sink
To clearly demonstrate the value brought by technological innovation, we have conducted an in-depth comparison between gravity casting and mainstream conventional heat sinks on the market across five key dimensions:
Comparison Dimension | Conventional heat sinks (Copper Tube + Ordinary Aluminum Alloy / Die Casting) | Gravity Casting (316 Stainless Steel Tube + A356 Gravity Casting + Fully Wrapped Structure) | Core Difference Analysis |
Vibration Resistance | Weak / Medium, Die-cast aluminum is brittle and prone to generate microcracks. Rigid connections easily loosen. | Extremely High, A356 offers high toughness, absorbing vibration energy without brittle fracture. Gravity casting provides a dense structure free of internal defects. Fully wrapped structure protects tubes from alternating stress. | Upgraded material toughness plus rigid structural design, completely eliminates vibration fatigue fracture. |
Corrosion Resistance | Medium / Poor, Copper tubes are prone to oxidation; aluminum alloy has weak salt spray resistance. Outer tube walls are directly exposed to corrosive environments. | Excellent, Fully wrapped structure physically isolates tubes from the external environment.316 stainless steel tubing delivers outstanding corrosion resistance. SUS304 connectors meet anti-corrosion requirements in general applications. | Structural isolation plus material upgrade ensures the pipeline itself never contacts corrosive sources. |
Thermal Conductivity Efficiency | High initially but decays rapidly. Copper pipes have good thermal conductivity, but their thermal resistance increases sharply after corrosion. The material has low thermal conductivity | Stable & High Efficiency, A356 (T6) thermal conductivity reaches 150+ W/(m·K). Inner walls never corrode, maintaining consistent efficiency. | Balances high thermal conductivity and long service life, delivering a higher overall energy efficiency ratio. |
Service Life | 3–5 years | Over 10 years | With high-toughness anti-vibration design and physical pipeline isolation, the service life increased by 2–3 times. |
Maintenance Cost | High， Requires regular inspection and replacement. | Extremely Low (Maintenance-Free) | "Install and forget", significantly reducing total cost of ownership (TCO). |
Comparison Conclusion
Although conventional heat sinks hold a slight advantage in initial thermal conductivity (due to the high thermal conductivity of copper), they have fatal weaknesses in adaptability to extreme working conditions and long-term reliability. Once exposed to vibration or corrosive environments, their high-performance characteristics degrade rapidly.
Through material restructuring and the innovative fully wrapped structure, gravity casting not only achieves excellent thermal conductivity values but also delivers an overall improvement in comprehensive heat dissipation efficiency and economic value by eliminating corrosion risks and preventing structural failure. For industrial and automotive-grade applications demanding high reliability and low maintenance costs, gravity casting represents an irreplaceable optimal solution.
Technical Specification Summary
Item | Specification / Description |
Main Body Material | A356 Aluminum Alloy (T6 heat treated, integrally formed by gravity casting) |
Pipeline Material | SUS316 Stainless Steel (molybdenum‑bearing, high corrosion resistance), fully wrapped in the aluminum alloy body |
Connectors Material | SUS304 Stainless Steel (inlet and outlet connectors) |
Connection Method | Fully wrapped casting integration (tight metallurgical bonding interface between aluminum alloy and stainless steel tubes) |
Surface Treatment | Pickling and passivation of pipelines + surface cleaning of the main body |
Salt Spray Resistance | Main body surface meets anti‑corrosion requirements for general industrial and outdoor applications; fully wrapped pipeline structure provides physical isolation with zero corrosion risk. |
Thermal Conductivity (Main Body) | 150–170 W/(m·K) (T6 condition) |
Compatible Media | Deionized water, ethylene glycol aqueous solution, various industrial coolants |
Typical Applications | New energy vehicle battery / motor cooling, marine engineering equipment, chemical machinery, outdoor communication base stations, wind power equipment |
Conclusion
By adopting gravity-cast A356 aluminum alloy for the main body instead of conventional die-cast aluminum, the gravity casting liquid-cooled radiator significantly improves toughness and fatigue resistance. Meanwhile, the fully wrapped structural design completely embeds 316 stainless steel pipelines inside the aluminum alloy body, with only SUS304 stainless steel connectors exposed as water inlet and outlet, achieving physical isolation between the pipelines and external corrosive environments at the structural level.
This innovative solution of "high-toughness body + high-strength pipelines + physical isolation" effectively solves heat dissipation problems under extreme vibration and highly corrosive environments, providing maintenance-free reliability for more than 10 years for high-end equipment.
Gravity Casting — Defying Extremes, Remaining Steady.