Process characteristics of ultrasonic welding
The solder joints of ultrasonic welding should have high joint strength and qualified surface quality. In addition to the obvious extrusion pits and protrusions on the edge of the solder joints on the surface, attention should be paid to the surface conditions of the solder joints in contact with the upper sonotrode. , Cracks and partial unfusion are not allowed. Therefore, the selection of ultrasonic welding form, joint design and welding parameter selection are very important.
Process characteristics of ultrasonic welding:
1) A wide range of materials that can be welded can be used for the welding of the same metal materials, especially materials with high electrical conductivity and high thermal conductivity (such as gold, silver, copper, aluminum, etc.) and some refractory metals, and can also be used for different properties The welding of dissimilar metal materials (such as heat conduction, hardness, melting point, etc.), metal and non-metal, plastics, etc., can also realize the welding of special structures such as large differences in thickness and multilayer foils.
2) The weldment is not energized, no external heating source is needed, no macroscopic pores and other defects appear in the joint, no brittle intermetallic compounds are generated, and no problems such as splashing of molten metal that easily occur during resistance welding.
3) The physical and mechanical properties of the weld metal do not undergo macroscopic changes, and the static load strength and fatigue strength of the welded joint are higher than those of the resistance welded joint, and the stability is good.
4) The oxide film or coating on the surface of the welded metal has little effect on the welding quality, and the preparation of the surface of the weldment before welding is relatively simple.
5) The electric energy required to form the joint is less, which is only 5% of that of resistance welding; the deformation of the weldment is small.
6) There is no need to add any binder, filler or solvent, and it has the advantages of simple operation, fast welding speed, high joint strength, and high production efficiency. The main disadvantage of ultrasonic welding is that it is limited by the power of the existing equipment, so the thickness of the weldment in contact with the upper sonotrode should not be too thick, and the joint form can only be lap joints, but butt joints are not yet applicable.