Friction welding (friction stir welding radiator / heat sink) refers to: The heat generated by the friction between the high-speed rotating welding tool and the workpiece is used to locally plasticize the material to be welded. When the welding tool moves forward along the welding interface, the plasticized material flows from the front to the back of the welding tool under the action of the rotational friction of the welding tool. And under the extrusion of the welding tool, a dense solid phase weld is formed.
Friction welding usually consists of the following four steps:
1. Convert mechanical energy into heat energy;
2. Material plastic deformation;
3. Forging pressure under thermoplasticity;
4. Intermolecular diffusion and recrystallization.
The main advantages of friction stir welding heat sink are as follows:
(1) The microstructure change of the heat-affected zone of the welding joint of the heat sink is small. The residual stress is relatively low, and the welding workpiece is not easy to deform;
(2) It can complete the welding of long welds, large cross-sections, and heat sinks at different positions at one time.
(3) The operation process is convenient to realize mechanization and automation, the equipment is simple, the energy consumption is low, the efficiency is high, and the requirements for the working environment are low.
(4) No need to add welding wire, no need to remove oxide film before welding when welding aluminum alloy, no need for shielding gas, low cost;
(5) Weldable heat-crack sensitive heat sink material, suitable for welding dissimilar materials;
(6) The welding process of the heat sink is safe, pollution-free, smoke-free, and radiation-free.
The biggest difference between friction stir welding and traditional fusion welding is that during the entire welding process, the temperature at which the metal to be welded gains energy does not reach its melting point. That is, the metal of the heat sink is solid-phase connected in a forging-like state in a thermoplastic state.
Compared with traditional fusion welding, friction-welded radiators have high-quality welded joints—— It can reach the strength of the weld seam and the strength of the base material, and the welding efficiency is high, the quality is stable, and the consistency is good. Welding of dissimilar heat sink materials can be realized.
Friction welding (the heat sink of friction stir welding) is connected with its high-quality, high-efficiency, energy-saving, and pollution-free technical characteristics. New technologies and traditional industries such as aviation, aerospace, nuclear energy, weapons, automobiles, electric power, marine development, and machinery manufacturing have been used more and more widely.
