Friction stir welding （FSW）technology is a solid-phase connection technology.

It can seal and connect water chambers with the outer cover, which are  formed by different processes .This method does not require solder or flux, and can ensure that the entire weld joint obtains a uniform and consistent welding depth and a dense weld structure in the forged state. It has good sealing performance, high weld strength, and is close to the base material.

ü FSW & Extrusion 

Suitable for using extrusion technology to directly shape the cold plate flow channel, and opening the cycle through machining. The liquid cooling plate components are assembled using friction welding technology for welding and sealing. The surface of this type of liquid cooling plate is not suitable for too many screw holes.

ü FSW C&  Die casting

Die casting followed by friction stir welding: The water chamber is formed using die casting technology, which controls issues such as impurities and pores in the process. Further use friction welding for connection, which needs to improve reliability to avoid water leakage issues.

ü Good heat uniformity

Friction stir welding water-cooled plates have safer and more stable heat dissipation performance. Friction stir welding water-cooled plates have larger flow channels, further reducing thermal resistance. Especially in dealing with complex flow channels and certain flow channels with height differences, it has more flexibility.

ü High reliability of joints

There are no welding porosity defects, element burning damage, or thermal cracks in the weld seam. As a solid-state welding process, friction stir welding is a basically defect free connection method, ensuring high reliability without leakage.

ü High material strength

 FSW is a solid-state connection that does not require heating of the entire material, so the substrate will not soften. In addition, the material strength of the joint part is equal to or higher than the strength of the base material.

ü Flow channel design: Design the cold plate flow channel structure based on manufacturing process, product conditions, thermal resistance distribution, and other factors, including the size of the cold plate, flow channel structure, and inlet and outlet positions.

ü The flow channel design needs to meet the following requirements for friction stir welding process:

Welding structure of cover plate: There are mainly three types of welding structures: overlap, butt overlap, and non planar. The butt overlap is a conventional water-cooled plate welding structure, which has the best welding effect. The overlap step of the cover plate is not less than 1mm to avoid collapse during the welding process.

Cover plate machining allowance: As the surface needs to be milled flat after welding, the thickness of the cover plate generally needs to have CNC machining allowance. The general cover plate thickness is 2-3mm, with an allowance of about 0.5mm, which can meet the pressure within 1 megapascal.

ü Weld edge margin: There should be a margin of friction stir welding stirring head at the edge of the weld. Generally, for a 3mm cover plate, at least 5mm margin should be left at the edge to avoid edge welding collapse. It is best to communicate with the welding process party before design.

ü Friction stir welding has a simple welding process, high production efficiency, and is suitable for mass production.

ü The welding process does not require additional welding materials, which is economical and environmentally friendly.

ü Walmate ready to provide professional and more economical opinions based on your specific application scenario and demand scale.