In recent years, as new energy, 5G communications, industrial control, and high-end electronic equipment iterate towards high power, miniaturization, and high density, aluminum profile radiators are the core components of passive heat dissipation. Their comprehensive heat dissipation efficiency, stability, and service life have become key factors restricting equipment performance. Industry practice shows that the thermal conductivity of aluminum profile substrates tends to be stable, and the surface treatment process has become the core variable to widen the gap in heat dissipation performance of radiators and optimize the adaptability to working conditions. Different surface treatment methods directly determine the heat dissipation performance of the radiator in different scenarios by changing the profile surface thermal radiation rate, heat dissipation contact area, surface thermal resistance and protective performance.
The heat dissipation principle of aluminum profile radiators mainly includes three core dimensions: heat conduction, heat convection, and heat radiation. Although raw aluminum profiles have excellent thermal conductivity, their surfaces are smooth and their infrared thermal radiation rate is extremely low, only 0.05-0.2. Most of the heat cannot be dissipated through radiation, and exposed aluminum is prone to oxidation, corrosion, and dust accumulation. Long-term use will significantly reduce the heat dissipation efficiency. The core value of the surface treatment process is not to simply improve the thermal conductivity of aluminum materials, but to optimize heat convection and thermal radiation efficiency, while reducing the loss of the heat dissipation system caused by environmental interference, to achieve dual breakthroughs in short-term heat dissipation improvement and long-term performance stability.
Differential effects of mainstream surface treatment processes on heat dissipation performance
The current mainstream surface treatment processes in the radiator industry include anodizing, black hard anodizing, sandblasting, micro-arc oxidation, plastic spraying, etc. The differences in film properties and surface structures of various processes bring about completely different heat dissipation performance and scene adaptability.
1. Natural anodizing: basic protection, extremely low heat dissipation loss
Natural anodizing is the most common basic treatment process for radiators. It electrochemically generates a dense aluminum oxide film on the surface of the aluminum material. The thickness of the film is generally controlled at 8-12 μm. From the perspective of heat dissipation performance, the thermal conductivity of the aluminum oxide film is only 1-1.5 W/(m·K), which is much lower than that of the aluminum substrate. However, because the film layer is extremely thin and closely combined with the substrate, the increase in the overall thermal resistance is less than 2%, and it has almost no negative impact on the thermal conductivity performance.
This process mainly optimizes the corrosion resistance, anti-oxidation and insulation properties of the radiator to avoid heat dissipation failure caused by oxidation corrosion of aluminum materials after long-term use. However, the thermal radiation rate of the surface of the profile after natural oxidation is limited, and it is only suitable for forced air cooling and high wind speed conditions. The heat dissipation gain is not obvious in natural convection scenarios, and it is mostly used in conventional power supplies and ordinary industrial control equipment radiators.
2. Black anodizing: natural convection heat dissipation core is optimized, and the efficiency is significantly improved.
Black anodizing is the mainstream process in current high heat dissipation demand scenarios, and it is also the most cost-effective heat dissipation optimization solution recognized by the industry. Compared with natural oxidation, black oxidation greatly improves the infrared heat radiation capability of the profile surface through special dyeing and sealing processes. Actual measurement data shows that the thermal emissivity of raw aluminum profiles is only 0.1-0.2, while the emissivity of black anodized profiles can reach 0.85-0.9, and the radiation heat dissipation efficiency is increased by 4-9 times.
Under natural convection conditions, thermal radiation accounts for more than 40% of the overall heat dissipation. The overall heat dissipation efficiency of the radiator with standardized black anodization can be increased by about 8%, and the film thickness is controllable, the thermal resistance is stable, and there will be no heat dissipation attenuation problem. At the same time, it retains excellent insulation and anti-corrosion properties, making it perfectly suitable for equipment scenarios without forced air cooling such as LED lamps, sealed cabinets, smart homes, and 5G micro base stations.
3. Sandblasting: Increase the heat dissipation area and strengthen convection heat transfer
The sandblasting process uses high-speed and high-pressure abrasives to impact the surface of the profile to form a uniform micro-concave-convex structure. The core function is to expand the effective heat dissipation surface area of the radiator and enhance the convection heat transfer efficiency between the air and the profile. The surface of smooth aluminum profiles has high air adhesion and poor circulation, while the rough surface after sandblasting can break the air layer stagnation and increase the heat exchange rate.
This process has no problems with film layer thickening or thermal resistance increase. It has outstanding advantages in harsh heat dissipation environments with airtight, no wind, and low wind speed, and can effectively improve the natural convection heat dissipation effect. However, sandblasting alone has no protective capabilities, and the profiles are prone to oxidation, discoloration, and dust accumulation. It is usually used with an anodizing process to take into account heat dissipation optimization and surface protection. It is widely used in industrial frequency converters and new energy electronically controlled radiators.
4. Micro-arc oxidation: High-end working conditions combine efficient heat dissipation and ultra-high protection
Micro-arc oxidation is an advanced process that has emerged in the field of high-end radiators in recent years. It relies on high-voltage discharge technology to grow a ceramic oxide film in situ on the surface of aluminum, completely breaking through the performance upper limit of traditional anodizing. According to continuous test data from the Institute of Process Engineering of the Chinese Academy of Sciences from 2024 to 2026, the hardness of the micro-arc oxidation film layer can reach more than HV1200, the wear resistance is three times that of traditional anodizing, while retaining an ultra-high thermal radiation rate of 0.85-0.9.
The biggest advantages of this process are zero heat loss, high stability, and strong anti-interference. The film layer is dense and has no pores. It will not crack or fall off due to long-term high temperature, vibration, or humid environment, and can maintain stable radiation heat dissipation capabilities for a long time. Although the process cost is high, it is the core upgrade direction of high-end radiators to perfectly adapt to high-frequency vibration, high-load, and high-reliability demand scenarios such as server cooling modules, new energy vehicle power cooling, and high-end industrial control high-power equipment.
5. Spraying/spraying process: excellent protection, obvious loss in heat dissipation
Coating processes such as plastic spraying and painting will form a thick organic coating on the surface of aluminum profiles, which has excellent protection, anti-rust, and insulation effects, but has a significant negative impact on heat dissipation performance. The thermal conductivity of organic coatings is extremely low, which will greatly increase the surface thermal resistance and hinder heat conduction and convection. At the same time, the coating is prone to aging, powdering, and dust accumulation. Long-term use will lead to a continued decline in heat dissipation efficiency.
Therefore, radiators with high heat dissipation requirements are strictly prohibited from using thick-layer plastic spraying. This process is only suitable for ordinary aluminum profile accessories that have extremely low heat dissipation requirements and focuses on appearance protection. It is not suitable for high-power and high-precision heat dissipation equipment.
Industry core consensus: process selection determines the overall energy efficiency of the radiator
Combining the measured data and engineering application experience of the radiator industry in 2026, the industry has formed a clear technical consensus: the core logic of surface treatment of aluminum profile radiators is to adapt to working conditions, control resistance and increase radiation, and achieve long-term stability. Thermal conductivity is mainly determined by the aluminum base material, and surface treatment can hardly improve it. However, the radiation and convection heat dissipation efficiency can be greatly improved by optimizing the surface emissivity and heat dissipation area. At the same time, reasonable surface treatment can avoid heat dissipation attenuation caused by corrosion, dust accumulation, and aging, ensuring long-term stable operation of the equipment.
From the perspective of selection principles: conventional low-power, forced air-cooled equipment can choose natural color anodizing, taking into account cost and basic stability; natural convection and closed working conditions give priority to black anodizing to achieve optimal heat dissipation efficiency; industrial harsh working conditions, high vibration and high load equipment are suitable for sandblasting + anodizing combined processes; high-end high-power, high-reliability scenarios prefer micro-arc oxidation technology; all high-heat dissipation scenarios need to avoid thick-layer plastic spray coating processes.
Industry development trend: lightweight, efficient, long-term process iteration
As downstream industries continue to increase their requirements for energy efficiency levels, service life, and environmental adaptability of cooling equipment, the aluminum profile radiator surface treatment industry is accelerating its iteration. The traditional single protection process is gradually upgraded to the integrated process of "heat dissipation optimization + long-term protection + insulation adaptation". Thin-layer high-radiation oxidation process, low-loss micro-arc oxidation process, and refined sandblasting composite process have become hot spots in research and development and application.
Industry experts said that in the future, the performance competition of radiators will shift from competition in base material specifications to competition in surface refinement treatment processes. By accurately controlling the film thickness, surface roughness, and emissivity parameters, the heat dissipation efficiency can be improved by 5% to 15% without increasing the volume and weight of the radiator. It perfectly adapts to the development trend of miniaturization and high power of electronic equipment, and provides core heat dissipation support for the upgrading of new energy, high-end manufacturing, and communications industries.
