Brazing Sheet
Author:Frank Time:2023-05-16
What is brazing sheet
Blazing sheet refers to the layered aluminum alloy composed of aluminum alloy whose melting temperature is lower than the core material melting point, cladded one side or both sides by core material. Brazing plate is mainly used to manufacture components of motor vehicles’ heat exchange system.
Cladding structure of brazed sheet foundation
cladding structure
There are two kinds of cladding:Commonly used brazing layer materials: Al-Si(4xxx)
Commonly used sacrificial anode material(Anticorrosive coating): AL-Zn-Cr（7072）,etc.
Commonly used Core material: Al-Mn(3xxx),Al-Si-Mg(6xxx)Common function of brazing aluminum sheet alloy elements
The function of Mn
Aluminum alloy with Mn as the main alloy element cannot be strengthened by heating, and it has good corrosion resistance. It can also be called antirust aluminum. It has good welding performance and good plasticity.
The function of Zn
The corrosion potential of this kind of alloy is reduced. The more Zn is added, the more potential is reduced. The heatsink after punching is first corroded as an anode to protect the media channel. Reduce the strength of the oxide film on the alloy surface, the surface will be easy to peel off and completely corroded, so as to inhibit corrosive pitting. However, if the content of Zn is too high, it may accelerate the corrosion of the heatsink, which will cause the heatsink to lose its cooling effect and reduce its service life.
The function of Si
The lowest melting point of Al-Si alloy can be 577 ℃ near eutectic point, which is its advantage as brazing material.
After recombination, the Si element will diffuse to the matrix alloy due to the gradient of concentration, forming [Al (MnFe) Si] anode strip, which makes the corrosion preferentially occur on the sub surface layer of the matrix.
Si can change the fluidity of solder, make the material uniform and fine, and improve the brazing quality.
The function of Mg
Mg in the cladding layer is an activator and getter to ensure the quality of vacuum brazing, but it has a certain impact on the corrosion resistance of composite plates.
Performance advantages of aluminum brazing plate in heat exchanger
- Heat transfer rate: good thermal conductivity to dissipate heat
- Corrosion resistance performance: cannot be corroded by refrigerant or coolant
- Strength: high strength,
- Weight: as light as possible,
- Anti-sag performance: no high-temperature buckling during brazing
Application of Brazed Aluminum Plate in Automobile Heat Exchanger
Under the background of lightweight and electrification, Aluminum has the outstanding cost performance as the automobile heat transfer materials.
The density of aluminum is 2.7g/cm3, which is only 34% of that of steel and 30% of that of copper.
Brazed Aluminum sheet in Automobile Heat Exchanger
The thermal conductivity of pure aluminum is 237W/m.K, pure copper is 398W/m.K, pure silver is 411W/m.K, iron is 73W/m K. The thermal conductivity performance of aluminum is not as good as that of silver and copper, but it is much higher than that of iron; The price of Aluminum is far lower than that of silver and copper. So, its cost performance is outstanding.
Different proportion of aluminum materials in the automobile heat exchange system: brazed sheet metal 29%, Die-casting 23%, extruded tube 23%, heat dissipation fin foil 21%, and others 4%.
Proportion of brazed aluminum sheet used in automobile heat exchanger
Engine radiator
The radiator is composed of a water inlet chamber, a water outlet chamber, a radiator core, a fan, etc. It adopts the combination of water cooling and air cooling to dissipate heat.
Among them, radiator cores are classified as fin-tube radiator core and tube belt radiator core.
classification of condensers
| classification | fin-tube radiator | Tube belt radiator | Advection radiator |
|---|---|---|---|
| advantage |
High voltage resistance High stiffness and strength |
Simple manufacturing process Low cost |
It has the 30%-40% higher heat dissipation efficiency than that of the tube belt type |
| disadvantage |
Complicated manufacturing process high cost Large volume |
The structural stiffness is not as good as that of the fin-tube radiator The heat dissipation efficiency is 15% - 20% higher than that of the fin-tube radiator |
expensive |
| application |
Diesel engine Coach engine |
Car engine | Limousine engine |
Customer Example for the Brazing Aluminum Plate of Engine Radiator
| Alloy | Temper |
Thickness (mm) |
Tolerance (mm) |
Clad Ratio(%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 4343/3003 | O | 1.2~3.0 | ±0.03 | 5~10 | 100~150 | ≥45 | 25 |
| 4343/3003/7072 | O | 1.2~3.0 | ±0.03 | 5~10 | 100~150 | ≥45 | 25 |
Oil cooler
The oil cooler is a device to accelerate the heat dissipation of lubricating oil and keep it at a lower temperature.
On the engine with high performance and high-power intensified, because of the large heat load, oil cooler must be installed. Common turbocharged engines and diesel engines are generally equipped with oil coolers.
Air vs Water cooled oil cooler
Customer Example for Brazing Aluminum Plate of oil cooler
| Alloy | Temper |
Thickness> (mm) |
Tolerance (mm) |
Clad Ratio (%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 3003 (inner fin) | O | 0.2~0.3 | ±0.007 | None | 100~150 | ≥45 | 15 |
| 6951(inner fin) | O | 0.2~0.3 | ±0.007 | None | 115~165 | ≥50 | 15 |
| 3003(external fin) | H14 | 0.1~0.15 | ±0.005 | None | 150~200 | ≥120 | 1 |
Air conditioning condenser
Air conditioning condenser in cars
The condenser can convert gas or steam into liquid, and transfer the heat to the air around the pipe. The working process of the condenser is the exothermic process, so the temperature of the condenser is high.
The example for Brazing Aluminum Plate of air conditioner condenser
| Alloy | Temper |
Thickness (mm) |
Tolerance (mm) |
Clad Ratio (%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 3003 | H14 | 0.08~0.12 | ±0.005 | None | 150~200 | ≥120 | 1 |
Air conditioner evaporator
Air conditioner evaporator
Air conditioning evaporator is one kind of evaporator. The function of the air conditioning evaporator is to make use of the phenomenon that the liquid cryogenic refrigerant is easy to evaporate under low pressure, convert into steam, and absorb the heat of the cooled medium, so as to achieve the refrigeration purpose.
Customer example of Air conditioner evaporator blazing aluminum plate| Alloy | Temper |
Thickness (mm) |
Tolerance (mm) |
Clad Ratio (%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 3003 | H14 | 0.08~0.12 | ±0.005 | None | 150~200 | ≥120 | 1 |
Heater
aluminum brazing sheet in heater
It is mainly used for preheating the engine in winter and heating the drivers’ cabs of the trucks or the passenger cabs of coaches. It mainly utilizes the heat generated by the engine.
Customer example for Brazing Aluminum Plate of heater
| Alloy | Temper |
Thickness (mm) |
Tolerance (mm) |
Clad Ratio (%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 3003 | O | 0.2~0.3 | ±0.01 | None | 100~150 | ≥45 | 15 |
| 3003 | H16 | 0.5~0.7 | ±0.02 | None | 150~210 | ≥120 | 1 |
| 4047 | H18 | 0.05~0.1 | ±0.005 | None | ≥200 | ≥170 | 0.5 |
Intercooler
aluminum brazing sheet in intercooler
The intercooler is the component of turbocharging. Its function is to reduce the temperature of high air temperature after turbocharging, reduce the heat load of the engine and increase the air intake volume and thus increase the power of the engine.
Customer example for Brazing Aluminum Plate of Intercooler
| Alloy | Temper |
Thickness (mm) |
Tolerance (mm) |
Clad Ratio (%) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
Elongation(%) Min |
|---|---|---|---|---|---|---|---|
| 4343/3003/4343 | H14 | 0.1~0.12 | ±0.005 | 8~12 | 150~120 | ≥120 | 1 |
| 4045/3003/4045 | H14 | 0.1~0.12 | ±0.005 | 8~12 | 150~200 | ≥120 | 1 |
Battery material and battery cooler
The temperature of the power battery of new energy vehicles will gradually increase while the driving process. When the temperature is too high, it may lead to the thermal runaway of the battery. So, it is very important to cool the battery pack.
brazing sheet of battery cooler
Customer example for brazing plate of battery cooler
| Parts | Material | Cladding rate of composite layer |
|---|---|---|
| Mainboard | 4104/3003/4104 | 10% |
| Side plate | 4104/6063/4104 | 10% |
| Pressing plate | 3003 | 0 |
Supplier of brazing aluminum plate: Signi Aluminum
We manufacture the core material and brazing metal combination products from numerous available alloys. The products are the most suitable for the using environment and customer requirement.
We are developing the aluminum material to form the welding joints with high reliability by adjusting the alloy setting of blazing filler metal, the cladding rate, the interface diffusion and flow control caused by the metal composition of core material.
In order to provide heat exchanger with high corrosion resistance, the compatibility with brazing counterpart (fin material or tube) shall also be considered, and the alloy design, metal composition and optimum tempering of core material shall be processed.
We are able to provide full range of aluminum brazing sheet for heat exchangers, composite fins, composite plates, composite strips, tube blanks and various weld tubes.
