Automobile Radiator & Low Temperature Vacuum Brazing Furnace

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In order to adapt to the overall development trend of the automobile industry, the radiator, one of the important parts of the cooling system, must also continuously improve its work efficiency and gradually lighten it to reduce production costs. The brazing process is generally suitable for the mass production of automobile radiators. Its production efficiency is relatively high, and the automation of the production process can be realized more conveniently, so as to ensure the basic quality level of the welded products. The quality of brazing workpieces is directly affected by various technical parameters in the production process.

1. Various Technical Parameters of Brazing Process

1.1 The drying temperature of the work piece After spraying the flux, the work piece should be further dried to remove the excess water contained in the flux. At the same time, the moisture adsorbed on the surface of the work piece must be removed to keep the work piece dry. Moisture corrodes the mesh belt and affects the brazing atmosphere in the brazing furnace body, and affects the brazing quality of the product. According to different product specifications, the set drying temperature is not the same. Therefore, before the formal production, it is necessary to repeatedly adjust the temperature through experiments to determine the most suitable temperature parameters. After the moisture on the surface of the workpiece is completely removed, the temperature during the drying operation should be as low as possible within the range required by the technical standards.

1.2 The temperature during the brazing operation The temperature during brazing is affected by the properties of the brazing filler metal and the base material of the product. Generally, the brazing temperature must match the melting point temperature of the brazing filler metal. If the temperature is too high, it is easy to cause the dissolution of the base material or produce other defects. If the temperature is too low, the phenomenon of virtual welding may occur, which reduces the strength of the joint. Therefore, in actual production, the temperature of the brazing operation should be adjusted appropriately according to the material properties of the product base material and the required brazing quality, and it is best to perform it in a low-temperature vacuum brazing furnace.

1.3 The holding time and the holding time of the mesh belt speed brazing should be set according to the size of the workpiece and the degree of interaction between the base material and the solder. Generally, larger workpieces need to be kept warm for a longer time, while the brazing filler metal strongly acts on the base material, and the required heat preservation time can be shorter. Adjusting the holding time can make the brazed joint stronger. The determination of the holding time can be achieved by adjusting the corresponding mesh belt speed. In actual production, after the brazing temperature is determined, the running speed of the mesh belt can be adjusted through experiments, so as to obtain the optimal length of heat preservation. If the brazing quality of the product during the brazing operation is stable and the cut is normal, in order to further improve the welding efficiency, the running speed of the mesh belt can be adjusted appropriately.

1.4 Oxygen content in the heating stage of brazing During the brazing operation, the brazing atmosphere in the brazing furnace body is very important. After the workpiece enters the heating stage of the brazing furnace, ensure that the nitrogen completely wraps the workpiece, and at the same time strictly monitor the oxygen concentration of the environment where the workpiece is located, to ensure that the nitrogen purity is above 5 9 (999%). If the oxygen content in the furnace body is too high, the workpiece will be seriously oxidized on the surface.For brazing quality, in order to ensure the brazing atmosphere in the furnace, the flow of nitrogen can be adjusted to achieve precise control of the oxygen content in the furnace.

1.5 The placement density of the welded product The density of the workpiece placed on the mesh belt will also affect the quality of the brazed joint. When the size of the workpiece itself is not large, but its quality is large, it is necessary to carry out related calculations and carry out related experiments to optimize the density of the placement of the workpieces.

2. Formation of Brazed Joints

2.1 Wetting and spreading the molten material Only the liquid solder with good wettability can be more easily filled into the extremely fine brazing seam. Wetting means that the solid-liquid phase interface replaces the original solid-gas phase interface. The liquid solder discharges the surface gas of the base material and spreads on its surface to form solder wetting. The temperature and different material properties during the brazing operation will affect the wetting of the solder.

2.2 During the capillary filling and brazing operation, the liquid solder should be able to automatically flow into the brazing seam without relying on external force. The brazing material flows in a small brazing seam by capillary action. What liquid brazing filler metal relies on to fill the brazing joints is its unique capillary action in the process of flowing between the gaps.

2.3 The interaction between the base material and the liquid solder The interaction between the base material and the liquid solder changes the structure of the original solder, resulting in a brazing seam with a different structure, and the composition of the solder is also The changes that have occurred, the composition of the brazing joints is also different from the original composition.

The welding quality of automobile radiators will directly affect the realization of the pressure resistance and air tightness of the radiator. The brazing technology is to weld the radiator’s heat pipe, heat sink, main sheet and other parts into a whole, and the core body and the aluminum alloy water chamber are assembled and then brazed as a whole, which saves some processes in the traditional process , Can effectively improve production efficiency and reduce production costs. Choose Shanghai Geheng Vacuum Technology Co., Ltd. for low temperature brazing furnace, the brand is trustworthy!

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