Application Of Friction Stir Welding In Cold Plate Processing

In the power electronic heat dissipation industry, cols plate heat dissipation is becoming popular. Due to the continuous pursuit of high reliability and low cost, traditional vacuum brazing technology has some drawbacks for certain industries and product structures.

The water cold plate adopts friction stir technology, which makes the design of the water channel more free, and the reliability of the seal is better. At the same time, it can be treated with hard anode surface.

Friction stir welding is a solid-phase connection method under the action of mechanical force and frictional heat. During the friction stir welding process, a cylindrical stirring head with a special shoulder and needle convex is rotated and slowly inserted into the workpiece to be welded. The frictional shear resistance between the stirring head and the welded material generates frictional heat, which makes the stirring head adjacent to the area. The material is thermally plasticized (the welding temperature generally does not reach or exceed the melting point of the material being welded). When the stirring head rotates and moves forward, the thermoplasticized metal material transfers from the front to the back Under the combined action of friction, heat generation and forging pressure between the head shoulder and the surface of the workpiece, a dense solid-phase connection joint is formed.

Technical features:

1. There are no fusion welding pore defects in the weld, no element burnout, no thermal cracks, and high reliability without leakage is always guaranteed;

2. There is no elemental segregation during solidification, the microstructure of the weld zone is isotropic, and there is no weld reinforcement;

3. The welding process is simple and belongs to the type of welding without flux: no wire filling, no groove opening, no pre-welding treatment, no protective gas:

4. The processing process is environmentally friendly, without light and gas pollution;

5. The welding area has small shrinkage and deformation;

6. Due to the popularization of equipment, the cost of friction stir welding will be further reduced and become a commonly used welding technology.