Friction welding

Friction welding is a method in which the workpiece is used for relative movement, and the heat generated by the friction of the contact surface is used as a heat source to cause the workpiece to undergo plastic deformation under pressure to perform welding.

After years of development, friction welding has developed from several traditional forms to more than 20 types, including friction stud welding, embedded friction welding, inertial friction welding, friction stir welding, linear friction welding, etc., which greatly expands friction welding Application areas. The shape of the welded parts has been expanded from a typical round cross-section to a non-circular cross-section (linear friction welding) and plate (friction stir welding), and the welded materials have been expanded from traditional metal materials to powder alloys, composite materials, functional materials, refractory Materials, and ceramic-metal and other new materials and dissimilar materials.

　　Friction welding is usually composed of four steps: the conversion of mechanical energy into thermal energy, plastic deformation of materials, forging pressure under thermoplasticity, and intermolecular diffusion and recrystallization. The biggest difference between friction 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 is a forging-like solid phase connection in a thermoplastic state.
Compared with traditional fusion welding, friction welding has the following advantages:

　　01 The welding quality of the joint is good and stable. The scrap rate of friction welding is also very low, about 1% of the general welding method. The crystallization of the weld zone is fine grains with good performance.

　　02 The weldment has high dimensional accuracy. Friction welding can be used not only to weld blanks, but also to weld assembled products. The groove processing of the weldment is easy.

　　03 Suitable for welding dissimilar steel and dissimilar metals. Friction welding can not only weld ordinary dissimilar steels, but also dissimilar steels and dissimilar metals with very different mechanical and physical properties at room temperature and high temperature. In addition, it can also weld dissimilar metals that produce brittle alloys, such as aluminum-copper, aluminum-steel and so on.

　　04 The welding machine has low power and energy saving. Compared with friction welding and flash welding, the energy saving is about 80~90%.

　　05 The workplace of friction welding is sanitary, free of sparks, arcs and harmful gases, which is conducive to environmental protection.