Vacuum brazing process of liquid cooling plate

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There are two main materials for liquid cooling plates: copper and aluminum.

Copper is expensive and weighs much more than aluminum of the same volume. Therefore, in many places, aluminum is used wherever it can be used, and copper is chosen as a last resort. Aluminum alloy liquid cooling plates also have various sizes and shapes and corresponding different manufacturing processes according to the usage scenarios.

Welding is a very important process in the processing of water cooling plates. Nowadays, the welding processing technology of water cooling plates is mainly divided into three categories: energized diffusion bonding, vacuum brazing and stir friction welding. Vacuum brazing liquid cooling plates have the characteristics of flexible design structure and high welding efficiency, and are widely used in the processing of some aluminum alloy products.

Welding principle of vacuum brazing

1.It refers to the heating and welding of workpieces in a vacuum chamber, which is mainly used for the welding of products requiring high quality and easily oxidized materials;

2.Brazing belongs to solid phase connection. The base material does not melt during brazing. Since a brazing material with a lower melting point than the base material is used, the heating temperature is lower than the base material solidus line and higher than the base material liquidus line. It is a connection method;

3.The connected parts and the brazing material are heated until the brazing material melts, and the liquid brazing material is used to wet, spread, dissolve and diffuse with the base material on the base material surface, wet, capillary flow, fill the gap, dissolve and diffuse with the base material to achieve the connection between the parts;

4.Vacuum brazing is to remove the oxide film with the help of different action mechanisms under vacuum environment. Because no brazing agent is used, the corrosion resistance of the product is significantly improved;

5.The brazing material has good wettability and fluidity, and can weld more complex and narrow channel parts, with a high yield rate and good safety production conditions.

Advantages of vacuum brazing process

1.Multiple adjacent welds can be brazed at one time to form the same surface. The furnace can be stacked during welding. According to the capacity of the furnace, multiple components can be brazed in the same furnace to improve welding efficiency.

2.The welded product can withstand high pressure without deformation.

3.The fixture is universal and the cost is one-time investment. Usually, no special design and investment is required for the product.

4.The workpiece is heated evenly as a whole, with small thermal stress, and the deformation can be controlled to a minimum, which can achieve small margin flatness and easy processing.

5.The workpiece is under vacuum conditions, and there will be no oxidation, carbon increase, decarburization, pollution and deterioration. The brazing seam is beautiful and difficult to corrode.

6.The corresponding cold plate flow channel structure can design complex flow channels according to the parameters, so that the product performance and heat dissipation characteristics can be better and more stable.

Disadvantages of vacuum brazing process

1.The hardness of the material decreases after high-temperature welding, and the cold plate characteristics require re-heat treatment to increase the hardness, which increases the cost.

2.The welding operation has high process requirements, high technical difficulty, high energy consumption and long time.

3.The cleaning and environmental protection costs before welding are high.

Learn More:

What Is Aluminum Vacuum Brazing

Titanium alloy vacuum brazing process

Why Switch To Brazing In A Vacuum Furnace