Ultrasonic metal welding is similar to friction welding, but there are differences. Ultrasonic welding takes a short time and the temperature is lower than recrystallization; it is also different from pressure welding, because the added static pressure is much smaller than pressure welding. It is generally believed that in the initial stage of the ultrasonic welding process, the tangential vibration removes the oxides on the metal surface, and the protruding part of the rough surface produces repeated micro-welding and destruction processes, which increases the contact area and increases the temperature of the welding zone. High, plastic deformation occurs at the interface of the weldment. In this way, under the action of contact pressure, when they approach each other to the distance where atomic gravity can act, a solder joint is formed. If the welding time is too long, or the ultrasonic amplitude is too large, the welding strength will decrease or even be destroyed.
Principle:
Ultrasonic metal welding machine uses tens of thousands of high-frequency vibration waves per second to transmit to the surface of two metal workpieces to be welded, and then applies a certain pressure to make the metal surfaces rub against each other to form fusion between molecular layers. To achieve the purpose of welding.
Features:
(1) The two objects to be welded are overlapped and bonded into a solid state by ultrasonic vibration and pressure. The bonding time is short, and the bonding part does not produce casting structure (rough surface) defects.
(2) Compared with the method of ultrasonic welding and resistance welding, the life of the mold is longer, the time for mold repair and replacement is less, and it is easy to realize automation.
(3) Ultrasonic welding can be performed between the same metal and different metals, which consumes much less energy than electric welding.
(4) Compared with other pressure welding, ultrasonic welding requires less pressure, and the deformation is less than 10%, while the deformation of cold pressure welding reaches 40%-90%.
(5) Ultrasonic welding does not require pretreatment of the welded surface and post-welding post-treatment like other welding.
(6) Ultrasonic welding does not require external factors such as flux, metal fillers, and external heating.
(7) Ultrasonic welding can minimize the temperature effect of the material (the temperature of the welding zone does not exceed 50% of the absolute melting temperature of the metal to be welded), so that the metal structure does not change, so it is very suitable for welding applications in the electronic field.
Advantages of metal welding machine:
High fusion strength;
Close to cold processing, the workpiece is not annealed, and there is no oxidation trace;
Good electrical conductivity after welding, very low or almost zero resistivity;
Low requirements on the surface of the welded metal, both oxidation and electroplating can be welded;
The welding time is short, without any flux, gas, solder.
Welding without sparks, environmental protection and safety.
Disadvantages of metal welding machine:
The metal parts to be welded should not be too thick, and the solder joints should not be too large, which requires pressure